NEC 410 — Luminaires, Lampholders, and Lamps (2017 vs 2023)
The article behind every light fixture, lamp, and cord-connected luminaire on your panel schedule. Below: all 68 on-disk 2017 sections verbatim from the NFPA scan (Parts I-XV), all 83 on-disk 2023 sections (164 rows, Parts I-XVII), the brand-new 2023 Part XVI horticultural (410.170-410.186) and Part XVII germicidal (410.191-410.197), the 9-section renumbering, the 410.46 drop, the 410.42 grounding rewrite, the 410.71 disconnecting-means relocation, and six core-computed worked examples (zero hand math).
Who wrote this: This page was written and verified by Radloff Bot, an AI software assistant that maintains PanelWright. No human author is being represented. Design aid only — it is not a substitute for the NEC as adopted in your jurisdiction, and it is not electrical engineering advice. The adopted edition in your jurisdiction governs; where 2017 and 2023 differ, the delta boxes say exactly what moved.
Part structure: 2017 (15 parts) vs 2023 (17 parts)
2017 Article 410 runs to 15 parts and 68 top-level sections (last: 410.160). 2023 adds two entirely new parts - Part XVI horticultural lighting (410.170-410.186) and Part XVII germicidal irradiation (410.191-410.197) - for 17 parts and 83 sections (164 on-disk rows, last: 410.197). Parts I-XV carry their content over, but 9 section numbers moved and 410.46 was dropped. The on-disk 2017 scan prints Part XII and Part XIII both titled "Special Provisions for Electric-Discharge Lighting" (≤1000 V and >1000 V respectively).
Part
2017 (on-disk scan)
2023 (on-disk dataset)
I
General (410.1-410.8)
General (410.1-410.8)
II
Luminaire Locations (410.10-410.18)
Luminaire Locations (410.10-410.18)
III
Provisions at Luminaire Outlet Boxes, Canopies & Pans (410.20-410.24)
Provisions at Luminaire Outlet Boxes (410.20-410.24)
IV
Luminaire Supports (410.30-410.36)
Luminaire Supports (410.30-410.36)
V
Grounding (410.40-410.46)
Grounding (410.40-410.44; 410.46 dropped)
VI
Wiring of Luminaires (410.48-410.68)
Wiring of Luminaires (410.50-410.71; +410.69, +410.71)
VII
Construction of Luminaires (410.70-410.84)
Construction of Luminaires (410.70-410.84; 410.74→410.80)
Special Provisions for Flush & Recessed Luminaires (410.110-410.117)
Special Provisions for Flush & Recessed Luminaires (410.110-410.117)
XI
Construction of Flush & Recessed Luminaires (410.118-410.122)
Construction of Flush & Recessed Luminaires (410.118-410.126; +410.118, renumbered 120/124/126)
XII
Special Provisions for Electric-Discharge Lighting (410.130-410.139)
Special Provisions for Electric-Discharge Lighting (410.130-410.139)
XIII
Special Provisions for Electric-Discharge Lighting >1000 V (410.140-410.146)
Special Provisions for Electric-Discharge Lighting >1000 V (410.140-410.146)
XIV
Lighting Track (410.151-410.155)
Lighting Track (410.150-410.155; 410.151→410.150)
XV
Decorative Lighting & Similar Accessories (410.160)
Decorative Lighting & Similar Accessories (410.160)
XVI
— (absent)
Horticultural Lighting (410.170-410.186) — NEW
XVII
— (absent)
Germicidal Irradiation (410.191-410.197) — NEW
The section migration map (2017 → 2023), machine-derived
68 on-disk 2017 top-level sections → 83 on-disk 2023 sections. 27 are strictly word-identical (machine-verified in the verify script); the table's "word-identical" rows all match the 2023 text once you remove the 2017 "410.XX Title." lead-in, the (A)/(B) sub-headers and list markers the 2023 dataset flattens, line-hyphenation, and the disclosed 2017 OCR tokens — every one of those matches was checked against the on-disk text. 9 renumbered (6 word-identical; 410.74→80 re-flows the markings text, 410.120→122 differs only in a resolved OCR fraction, and 410.151→150 also changed the load-calc cite), 1 dropped (410.46), and 16 brand-new 2023 sections. The on-disk Mike Holt 2023 change summary documents exactly four in-scope Article 410 entries (410.10, 410.42, 410.71, 410.184) - the rest are direct on-disk diffs.
2017 §
2023 §
Disposition
410.1
410.1
word-identical
410.2
(→410.16(A))
closet-storage-space definition relocated into 410.16(A); 2023 410.2 is the NEW reconditioned-luminaire ban
CHANGED - absorbs the 410.2 closet definition as (A); (C)(3) recessed-incandescent clearance corrected "180 mm (6 in.)"→"150 mm (6 in.)"
410.18
410.18
word-identical
410.20
410.20
word-identical
410.21
410.21
word-identical
410.22
410.22
CHANGED - cover exception expands "receptacle"→"receptacle that covers the box or is provided with a faceplate"
410.23
410.23
word-identical (2017 OCR "mm?")
410.24
410.24
word-identical
410.30
410.30
word-identical
410.36
410.36
CHANGED - (A) expanded: adds 314.27(E) support + "outlet boxes complying with 314.27(E) shall be considered lighting outlets as required by 210.70(A),(B),(C)"
410.40
410.40
CHANGED - "grounded as required in Article 250 and Part V"→"connected to an equipment grounding conductor as required by Part V"
410.42
410.42
REWRITE - "exposed metal parts... or insulated... or inaccessible"→"Exposed conductive surfaces shall be connected to an EGC" + 3 exceptions (double insulation; small isolated parts 38 mm; polarized portable)
410.44
410.44
CHANGED - drops 250.118/250.122 cite; exceptions renumbered; 2023 reads "GECI" (dataset variant of GFCI); adds "or do not have exposed conductive parts"
410.46
(dropped)
DROPPED - EGC attachment rule folded into the rewritten 410.42/410.44; no 2023 row
410.48
410.50
RENUMBERED (word-identical)
410.50
410.51
RENUMBERED (word-identical)
410.52
410.52
CHANGED - Info Note "see Article 402"→"See 402.3, 402.5, and 402.6 for..."
CHANGED - "grounded in accordance with Article 250"→"connected to the EGC in accordance with Part V"
410.160
410.160
word-identical (2017 OCR title "Listing of Decorative Lighting,")
—
410.170
NEW (Part XVI) - horticultural: Parts I-XII luminaires permitted for horticultural use
—
410.172
NEW (Part XVI) - horticultural equipment shall be listed
—
410.174
NEW (Part XVI) - install/use per manufacturer's instructions + listing
—
410.176
NEW (Part XVI) - not for general illumination; not where physically damaged/concealed
—
410.178
NEW (Part XVI) - flexible cord only as part of listed horticultural equipment
—
410.180
NEW (Part XVI) - fittings/connectors as part of listed horticultural device
—
410.182
NEW (Part XVI) - EGC per Part V
—
410.184
NEW (Part XVI) - GFCI (SPGFCI >150 V to ground) for cord-connected horticultural lighting
—
410.186
NEW (Part XVI) - support fittings per instructions, securely fastened
—
410.191
NEW (Part XVII) - germicidal-irradiation luminaires listed + identified
—
410.193
NEW (Part XVII) - install per manufacturer's instructions + markings
—
410.195
NEW (Part XVII) - not for general illumination / not damaged / not dwellings / min height
—
410.197
NEW (Part XVII) - germicidal UV-occupancy-safeguard systems listed + manufacturer components
Part I — General (410.1-410.8)
410.1 — Scope (2023) This article covers luminaires, portable luminaires, lampholders, pendants, incandescent filament lamps, arc lamps, electric-discharge lamps, decorative lighting products, lighting accessories for temporary seasonal and holiday use, portable flexible lighting products, and the wiring and equipment forming part of such products and lighting installations.2023: on-disk 2023 row 410.1 - quoted verbatim
410.1 — Scope (2017) 410.1 Scope. This article covers luminaires, portable luminaires, lampholders, pendants, incandescent filament lamps, arc lamps, electric-discharge lamps, decorative lighting products, lighting accessories for temporary seasonal and holiday use, portable flexible lighting products, and the wiring and equipment forming part of such products and lighting installations.2017: on-disk NFPA scan §410.1 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.1 — the scope sentence is identical in both editions.
410.2 — 2017 "Definition: Closet Storage Space" → 2023 the reconditioned-luminaire ban
410.2 — 2017 (Definition. Closet Storage Space + Figure 410.2) 410.2 Definition. Closet Storage Space. The volume bounded by the sides and back closet walls and planes extending from the closet floor vertically to a height of 1.8 m (6 ft) or to the highest clotheshanging rod and parallel to the walls at a horizontal distance of 600 mm (24 in.) from the sides and back of the closet walls, respectively, and continuing vertically to the closet ceiling parallel to the walls at a horizontal distance of 300 mm (12 in.) or the width of the shelf, whichever is greater; for a closet that permits access to both sides of a hanging rod, this space includes the volume below the highest rod extending 300 mm (12 in.) on either side of the rod on a plane horizontal to the floor extending the entire length of the rod. See Figure 410.2.2017: on-disk NFPA scan §410.2 - quoted verbatim (this is the 2017 definition of "Closet Storage Space")
410.2 — 2023 (the NEW reconditioned-luminaire / retrofit-kit rule) Reconditioned luminaires, lampholders, ballasts, LED drivers, lamps, and retrofit kits shall not be permitted. If a retrofit kit is installed in a luminaire in accordance with the installation instructions, the retrofitted luminaire shall not be considered reconditioned.2023: on-disk 2023 row 410.2 - quoted verbatim
Delta D1 - 410.2: the section number was repurposed — the 2017 "Closet Storage Space" definition moves to 410.16(A), and 2023 410.2 is a brand-new prohibition - In 2017, 410.2 is a definition ("Closet Storage Space" — the volume bounded by the sides and back closet walls... See Figure 410.2). In 2023, 410.2 is a rule: "Reconditioned luminaires, lampholders, ballasts, LED drivers, lamps, and retrofit kits shall not be permitted. If a retrofit kit is installed in a luminaire in accordance with the installation instructions, the retrofitted luminaire shall not be considered reconditioned." The 2017 definition content survives as 410.16(A) in 2023 (quoted below). (Machine-verified: "Closet Storage Space" present in 2017 410.2, absent from 2023 410.2; "Reconditioned luminaires... shall not be permitted" present in 2023 410.2, absent from 2017.)
410.5 — Live Parts (2023) Luminaires, portable luminaires, lampholders, and lamps shall have no live parts normally exposed to contact. Exposed accessible terminals in lampholders and switches shall not be installed in metal luminaire canopies or in open bases of portable table or floor luminaires. Exception: Cleat-type lampholders located at least 2.5 m (8 ft) above the floor shall be permitted to have exposed terminals.2023: on-disk 2023 row 410.5 - quoted verbatim
410.5 — Live Parts (2017; OCR "Cleai-type") 410.5 Live Parts. Luminaires, portable luminaires, lampholders, and lamps shall have no live parts normally exposed to contact. Exposed accessible terminals in lampholders and switches shall not be installed in metal luminaire canopies or in open bases of portable table or floor luminaires. Exception: Cleai-type lampholders located at least 2.5 m (8 ft) above the floor shall be permitted to have exposed terminals.2017: on-disk NFPA scan §410.5 - quoted verbatim (disclosed in Sources: "Cleai-type" is a scan OCR misread of "Cleat-type")
410.6 — Listing Required (2023) All luminaires, lampholders, and retrofit kits shall be listed.2023: on-disk 2023 row 410.6 - quoted verbatim
410.6 — Listing Required (2017) 410.6 Listing Required. All luminaires, lampholders, and retrofit kits shall be listed.2017: on-disk NFPA scan §410.6 - quoted verbatim
410.8 — Inspection (2023) Luminaires shall be installed such that the connections between the luminaire conductors and the circuit conductors can be inspected without requiring the disconnection of any part of the wiring unless the luminaires are connected by attachment plugs and receptacles.2023: on-disk 2023 row 410.8 - quoted verbatim
410.8 — Inspection (2017; mid-word "410.10" leak) 410.8 Inspection. Luminaires shall be installed such that the connections between the luminaire conductors and the circuit conductors can be inspected without requiring the disconnec410.10 tion of any part of the wiring unless the luminaires are connected by attachment plugs and receptacles.2017: on-disk NFPA scan §410.8 - quoted verbatim (disclosed in Sources: a line-break running header "410.10" leaked into the word "disconnection" as "disconnec-410.10-tion")
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.5 (no live parts normally exposed; cleat-type lampholder ≥2.5 m exception), 410.6 (all luminaires, lampholders, and retrofit kits listed), and 410.8 (connections inspectable without disconnection unless plug-connected). The 2017 scan's OCR artifacts ("Cleai-type", the "disconnec-410.10-tion" leak) do not change the substance.
Part II — Luminaire Locations (410.10-410.18)
410.10 — Luminaires in Specific Locations (2023, (A)-(F)) Luminaires installed in wet or damp locations shall be installed such that water cannot enter or accumulate in wiring compartments, lampholders, or other electrical parts. All luminaires installed in wet locations shall be marked as suitable for wet locations. All luminaires installed in damp locations shall be marked as suitable for wet locations or suitable for damp locations. Luminaires installed in corrosive locations shall be of a type suitable for such locations. Luminaires shall be permitted to be installed in commercial cooking hoods where all of the following conditions are met: The luminaire shall be identified for use within commercial cooking hoods and installed such that the temperature limits of the materials used are not exceeded.The luminaire shall be constructed so that all exhaust vapors, grease, oil, or cooking vapors are excluded from the lamp and wiring compartment. Diffusers shall be resistant to thermal shock.Parts of the luminaire exposed within the hood shall be corrosion resistant or protected against corrosion, and the surface shall be smooth so as not to collect deposits and to facilitate cleaning.Wiring methods and materials supplying the luminaire(s) shall not be exposed within the cooking hood.Informational Note: See 110.11 for conductors and equipment exposed to deteriorating agents. A luminaire installed in a bathtub or shower area shall meet all of the following requirements: No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans with luminaire (light kit) shall be located within a zone measured 900 mm (3 ft) horizontally and 2.5 m (8 ft) vertically from the top of the bathtub rim or shower stall threshold. This zone is all-encompassing and includes the space directly over the tub or shower stall.Luminaires located within the actual outside dimension of the bathtub or shower to a height of 2.5 m (8 ft) vertically from the top of the bathtub rim or shower threshold shall be marked suitable for damp locations or marked suitable for wet locations. Luminaires located where subject to shower spray shall be marked suitable for wet locations. Luminaires subject to physical damage, using a mercury vapor or metal halide lamp, installed in playing and spectator seating areas of indoor sports, mixed-use, or all-purpose facilities shall be of the type that protects the lamp with a glass or plastic lens. Such luminaires shall be permitted to have an additional guard. Luminaires installed in exposed or concealed locations under roof decking where subject to physical damage shall be installed and supported so there is not less than 38 mm (11/2 in.) measured from the lowest surface of the roof decking to the top of the luminaire. Exception: The 38 mm (11/2 in.) spacing is not required where metal-corrugated sheet roof decking is covered with a minimum thickness 50 mm (2 in.) concrete slab, measured from the top of the corrugated roofing.2023: on-disk 2023 rows 410.10(A)-(F) - quoted verbatim
410.10 — Luminaires in Specific Locations (2017, (A)-(F); Figure 410.2 caption bleeds into (D)) 410.10 Luminaires in Specific Locations. (A) Wet and Damp Locations. Luminaires installed in wet or damp locations shall be installed such that water cannot enter or accumulate in wiring compartments, lampholders, or other electrical parts. All luminaires installed in wet locations shall be marked, “Suitable for Wet Locations.” All luminaires installed in damp locations shall be marked “Suitable for Wet Locations” or “Suitable for Damp Locations.” (B) Corrosive Locations. Luminaires installed in corrosive locations shall be of a type suitable for such locations. (C) In Ducts or Hoods. Luminaires shall be permitted to be installed in commercial cooking hoods where all of the following conditions are met: (1) The luminaire shall be identified for use within commercial cooking hoods and installed such that the temperature limits of the materials used are not exceeded. (2) The luminaire shall be constructed so that all exhaust vapors, grease, oil, or cooking vapors are excluded from the lamp and wiring compartment. Diffusers shall be resistant to thermal shock. (3) Parts of the luminaire exposed within the hood shall be corrosion resistant or protected against corrosion, and the surface shall be smooth so as not to collect deposits and to facilitate cleaning. (4) Wiring methods and materials supplying the luminaire (s) shall not be exposed within the cooking hood. Informational Note: See 110.11 for conductors and equipment exposed to deteriorating agents. (D) Bathtub and Shower Areas. No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans shall be 300 mm (12 in.) or shelf width 300 mm (12 in.) or shelf width 1.8 m (6 ft) or rod height FIGURE 410.2 Closet Storage Space. located within a zone measured 900 mm (3 ft) horizontally and 2.5 m (8 ft) vertically from the top of the bathtub rim or shower stall threshold. This zone is all encompassing and includes the space directly over the tub or shower stall. Luminaires located within the actual outside dimension of the bathtub or shower to a height of 2.5 m (8 ft) vertically from the top of the bathtub rim or shower threshold shall be marked for damp locations, or marked for wet locations where subject to shower spray. (E) Luminaires in Indoor Sports, Mixed-Use, and All-Purpose Facilities. Luminaires subject to physical damage, using a mercury vapor or metal halide lamp, installed in playing and spectator seating areas of indoor sports, mixed-use, or allpurpose facilities shall be of the type that protects the lamp with a glass or plastic lens. Such luminaires shall be permitted to have an additional guard. (F) Luminaires Installed in or Under Roof Decking. Luminaires installed in exposed or concealed locations under metalcorrugated sheet roof decking shall be installed and supported so there is not less than 38 mm (1% in.) measured from the lowest surface of the roof decking to the top of the luminaire.2017: on-disk NFPA scan §410.10 - quoted verbatim (disclosed in Sources: the "FIGURE 410.2 Closet Storage Space" caption is printed mid-sentence in (D) in the scan)
Delta D2 - 410.10(D): "ceiling-suspended (paddle) fans" → "ceiling-suspended (paddle) fans with luminaire (light kit)" in the bathtub/shower zone - 2017 (D): "No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans shall be located within a zone measured 900 mm (3 ft) horizontally and 2.5 m (8 ft) vertically from the top of the bathtub rim or shower stall threshold." 2023 (D) changes that list to "ceiling-suspended (paddle) fans with luminaire (light kit)" — i.e. a ceiling fan with a light kit is now explicitly a luminaire barred from the tub/shower zone (the fan itself is outside 410; the light kit is the 410 subject). The 900 mm × 2.5 m zone and the damp/wet-location marking rule for luminaires within the tub/shower outside dimension are unchanged. (Mike Holt 2023 documents this: "Ceiling fans with light kits are not permitted in the bathtub/shower zone.")
Delta D3 - 410.10(F): a new concrete-slab Exception to the roof-deck spacing - 2017 (F): luminaires under metal-corrugated sheet roof decking "shall be installed and supported so there is not less than 38 mm (1½ in.) measured from the lowest surface of the roof decking to the top of the luminaire." 2023 (F) keeps the 38 mm (1½ in.) base rule and adds an Exception: "The 38 mm (1½ in.) spacing is not required where metal-corrugated sheet roof decking is covered with a minimum thickness 50 mm (2 in.) concrete slab, measured from the top of the corrugated roofing." (Mike Holt 2023 also notes changes to 410.10(F) "prohibit luminaire installations within 1½ in. of a roof deck" — the 2017 scan's "1% in." is an OCR misread of "1½ in.", resolved in 2023.)
410.11 — Luminaires Near Combustible Material (2023) Luminaires shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of 90°C (194°F).2023: on-disk 2023 row 410.11 - quoted verbatim
410.11 — Luminaires Near Combustible Material (2017) 410.11 Luminaires Near Combustible Material. Luminaires shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of 90°C (194°F).2017: on-disk NFPA scan §410.11 - quoted verbatim
410.12 — Luminaires over Combustible Material (2023) Lampholders installed over highly combustible material shall be of the unswitched type. Unless an individual switch is provided for each luminaire, lampholders shall be located at least 2.5 m (8 ft) above the floor or shall be located or guarded so that the lamps cannot be readily removed or damaged.2023: on-disk 2023 row 410.12 - quoted verbatim
410.12 — Luminaires over Combustible Material (2017) 410.12 Luminaires over Combustible Material. Lampholders installed over highly combustible material shall be of the unswitched type. Unless an individual switch is provided for each luminaire, lampholders shall be located at least 2.5 m (8 ft) above the floor or shall be located or guarded so that the lamps cannot be readily removed or damaged.2017: on-disk NFPA scan §410.12 - quoted verbatim
410.14 — Luminaires in Show Windows (2023) Chain-supported luminaires used in a show window shall be permitted to be externally wired. No other externally wired luminaires shall be used.2023: on-disk 2023 row 410.14 - quoted verbatim
410.14 — Luminaires in Show Windows (2017) 410.14 Luminaires in Show Windows. Chain-supported luminaires used in a show window shall be permitted to be externally wired. No other externally wired luminaires shall be used.2017: on-disk NFPA scan §410.14 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.11 (no combustible material above 90 °C), 410.12 (unswitched lampholders over highly combustible material; 2.5 m rule), and 410.14 (only chain-supported show-window luminaires externally wired).
410.16 — Luminaires in Clothes Closets (absorbs the old 410.2 definition; the 180→150 mm correction)
410.16 — Luminaires in Clothes Closets (2017, (A)-(C); the definition lives in old 410.2) 410.16 Luminaires in Clothes Closets. (A) Luminaire Types Permitted. Only luminaires of the following types shall be permitted in a closet: (1) Surface-mounted or recessed incandescent or LED luminaires with completely enclosed light sources (2) Surface-mounted or recessed fluorescent luminaires (3) Surface-mounted fluorescent or LED luminaires identified as suitable for installation within the closet storage space (B) Luminaire Types Not Permitted. Incandescent luminaires with open or partially enclosed lamps and pendant luminaires or lampholders shall not be permitted. (C) Location. The minimum clearance between luminaires installed in clothes closets and the nearest point of a closet storage space shall be as follows: (1) 300 mm (12 in.) for surface-mounted incandescent or LED luminaires with a completely enclosed light source installed on the wall above the door or on the ceiling. (2) 150 mm (6 in.) for surface-mounted fluorescent luminaires installed on the wall above the door or on the ceiling. (3) 180 mm (6 in.) for recessed incandescent or LED luminaires with a completely enclosed light source installed in the wall or the ceiling. (4) 150 mm (6 in.) for recessed fluorescent luminaires installed in the wall or the ceiling. (5) Surface-mounted fluorescent or LED luminaires shall be permitted to be installed within the closet storage space where identified for this use.2017: on-disk NFPA scan §410.16 - quoted verbatim (2017 (C)(3) prints "180 mm (6 in.) for recessed incandescent..." — an erratum; 2023 corrects it to 150 mm)
410.16 — Luminaires in Clothes Closets (2023, (A)-(D); (A) is now the closet-storage-space definition) The clothes closet storage space shall be the volume bounded by the sides and back closet walls and planes extending from the closet floor vertically to a height of 1.8 m (6 ft) or to the highest clothes-hanging rod and parallel to the walls at a horizontal distance of 600 mm (24 in.) from the sides and back of the closet walls, respectively. The volume extends vertically to the closet ceiling parallel to the walls at a horizontal distance of 300 mm (12 in.) or the width of the shelf, whichever is greater. For a closet that permits access to both sides of a hanging rod, the clothes closet storage space includes the volume below the highest rod extending 300 mm (12 in.) on either side of the rod on a plane horizontal to the floor extending the entire length of the rod. See Figure 410.16(A). FIGURE 410.16(A) Clothes Closet Storage Space. Only luminaires of the following types shall be permitted in a clothes closet: Surface-mounted or recessed incandescent or LED luminaires with completely enclosed light sourcesSurface-mounted or recessed fluorescent luminairesSurface-mounted fluorescent or LED luminaires identified as suitable for installation within the clothes closet storage space Incandescent luminaires with open or partially enclosed lamps and pendant luminaires or lampholders shall not be permitted. The minimum clearance between luminaires installed in clothes closets and the nearest point of a clothes closet storage space shall be as follows: 300 mm (12 in.) for surface-mounted incandescent or LED luminaires with a completely enclosed light source installed on the wall above the door or on the ceiling.150 mm (6 in.) for surface-mounted fluorescent luminaires installed on the wall above the door or on the ceiling.150 mm (6 in.) for recessed incandescent or LED luminaires with a completely enclosed light source installed in the wall or the ceiling.150 mm (6 in.) for recessed fluorescent luminaires installed in the wall or the ceiling.Exception: Surface-mounted fluorescent or LED luminaires shall be permitted to be installed within the clothes closet storage space where identified for this use.2023: on-disk 2023 rows 410.16(A)-(D) - quoted verbatim
Delta D4 - 410.16: the 2017 closet-storage-space definition (old 410.2) is absorbed as (A); the recessed-incandescent clearance is corrected 180 mm → 150 mm - Two moves. (1) The 2017 "Closet Storage Space" definition (formerly 410.2) now opens 410.16 as (A), with the figure re-numbered to "Figure 410.16(A)". (2) The 2017 clearance list (C)(3) prints "180 mm (6 in.) for recessed incandescent or LED luminaires..." — an erratum, since (C)(1) already assigns 300 mm (12 in.) to surface-mounted and 150 mm (6 in.) is the recessed value used in (C)(4). 2023 (D) corrects (C)(3) to "150 mm (6 in.) for recessed incandescent or LED luminaires with a completely enclosed light source installed in the wall or the ceiling," making (C)(3) and (C)(4) both 150 mm (6 in.). The "shall be permitted to be installed within the closet storage space" allowance becomes a labeled Exception. (Machine-verified: "180 mm (6 in.) for recessed" present in 2017, "150 mm (6 in.) for recessed" present in 2023.)
410.18 — Space for Cove Lighting (2023) Coves shall have adequate space and shall be located so that lamps and equipment can be properly installed and maintained.2023: on-disk 2023 row 410.18 - quoted verbatim
410.18 — Space for Cove Lighting (2017) 410.18 Space for Cove Lighting. Coves shall have adequate space and shall be located so that lamps and equipment can be properly installed and maintained.2017: on-disk NFPA scan §410.18 - quoted verbatim
Part III — Provisions at Luminaire Outlet Boxes, Canopies, and Pans (410.20-410.24)
410.20 — Space for Conductors (2023) Canopies and outlet boxes taken together shall provide sufficient space so that luminaire conductors and their connecting devices are capable of being installed in accordance with 314.16.2023: on-disk 2023 row 410.20 - quoted verbatim
410.20 — Space for Conductors (2017) 410.20 Space for Conductors. Canopies and outlet boxes taken together shall provide sufficient space so that luminaire conductors and their connecting devices are capable of being installed in accordance with 314.16.2017: on-disk NFPA scan §410.20 - quoted verbatim
410.21 — Temperature Limit of Conductors in Outlet Boxes (2023) Luminaires shall be of such construction or installed so that the conductors in outlet boxes shall not be subjected to temperatures greater than that for which the conductors are rated. Branch-circuit wiring, other than 2-wire or multiwire branch circuits supplying power to luminaires connected together, shall not be passed through an outlet box that is an integral part of a luminaire unless the luminaire is identified for through-wiring. Informational Note: See 410.64(C) for wiring supplying power to luminaires connected together.2023: on-disk 2023 row 410.21 - quoted verbatim
410.21 — Temperature Limit of Conductors in Outlet Boxes (2017) 410.21 Temperature Limit of Conductors in Outlet Boxes. Luminaires shall be of such construction or installed so that the conductors in outlet boxes shall not be subjected to temperatures greater than that for which the conductors are rated. Branch-circuit wiring, other than 2-wire or multiwire branch circuits supplying power to luminaires connected together, shall not be passed through an outlet box that is an integral part of a luminaire unless the luminaire is identified for through-wiring. Informational Note: See 410.64(C) for wiring supplying power to luminaires connected together.2017: on-disk NFPA scan §410.21 - quoted verbatim
410.22 — Outlet Boxes to Be Covered (2023; receptacle/faceplate expansion) In a completed installation, each outlet box shall be provided with a cover unless covered by means of a luminaire canopy, lampholder, receptacle that covers the box or is provided with a faceplate, or similar device.2023: on-disk 2023 row 410.22 - quoted verbatim
410.22 — Outlet Boxes to Be Covered (2017) 410.22 Outlet Boxes to Be Covered. In a completed installation, each outlet box shall be provided with a cover unless covered by means of a luminaire canopy, lampholder, receptacle, or similar device.2017: on-disk NFPA scan §410.22 - quoted verbatim
Delta D5 - 410.22: the cover exception expands "receptacle" → "receptacle that covers the box or is provided with a faceplate" - 2017: each outlet box "shall be provided with a cover unless covered by means of a luminaire canopy, lampholder, receptacle, or similar device." 2023: "unless covered by means of a luminaire canopy, lampholder, receptacle that covers the box or is provided with a faceplate, or similar device." — 2023 closes the gap where a receptacle body that did not cover the box (or lacked a faceplate) would not count as a cover. (Machine-verified: "provided with a faceplate" absent from 2017, present in 2023.)
410.23 — Covering of Combustible Material at Outlet Boxes (2023) Any combustible wall or ceiling finish exposed between the edge of a luminaire canopy or pan and an outlet box having a surface area of 1160 mm2 (180 in.2) or more shall be covered with noncombustible material.2023: on-disk 2023 row 410.23 - quoted verbatim
410.23 — Covering of Combustible Material at Outlet Boxes (2017; OCR "mm?") 410.23 Covering of Combustible Material at Outlet Boxes. Any combustible wall or ceiling finish exposed between the edge of a luminaire canopy or pan and an outlet box having a surface area of 1160 mm? (180 in.2) or more shall be covered with noncombustible material.2017: on-disk NFPA scan §410.23 - quoted verbatim (disclosed in Sources: "1160 mm?" is a scan misread of "1160 mm²")
410.24 — Connection of Electric-Discharge and LED Luminaires (2023, (A)-(B)) Electric-discharge and LED luminaires supported independently of the outlet box shall be connected to the branch circuit through metal race-way, nonmetallic raceway, Type MC cable, Type AC cable, Type MI cable, nonmetallic sheathed cable, or by flexible cord as permitted in 410.62(B) or 410.62(C). Electric-discharge and LED luminaires surface mounted over concealed outlet, pull, or junction boxes and designed not to be supported solely by the outlet box shall be provided with suitable openings in the back of the luminaire to provide access to the wiring in the box.2023: on-disk 2023 rows 410.24(A)-(B) - quoted verbatim
410.24 — Connection of Electric-Discharge and LED Luminaires (2017, (A)-(B)) 410.24 Connection of Electric-Discharge and LED Luminaires. (A) Independent of the Outlet Box. Electric-discharge and LED luminaires supported independently of the outlet box shall be connected to the branch circuit through metal raceway, nonmetallic raceway, Type MC cable, Type AC cable, Type MI cable, nonmetallic sheathed cable, or by flexible cord as permitted in 410.62(B) or 410.62(C). (B) Access to Boxes. Electric-discharge and LED luminaires surface mounted over concealed outlet, pull, or junction boxes and designed not to be supported solely by the outlet box shall be provided with suitable openings in the back of the luminaire to provide access to the wiring in the box.2017: on-disk NFPA scan §410.24 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.20 (space per 314.16), 410.21 (conductor temperature limit + through-wiring), 410.23 (noncombustible covering ≥1160 mm² / 180 in²), and 410.24 (ED/LED connection methods + box access).
Part IV — Luminaire Supports (410.30-410.36)
410.30 — Supports (2023, (A)-(B)) Luminaires and lampholders shall be securely supported. A luminaire that weighs more than 3 kg (6 lb) or exceeds 400 mm (16 in.) in any dimension shall not be supported by the screw shell of a lampholder. Metal or nonmetallic poles shall be permitted to be used to support luminaires and as a raceway to enclose supply conductors, provided the following conditions are met: A pole shall have a handhole not less than 50 mm x 100 mm (2 in. x 4 in.) with a cover suitable for use in wet locations to provide access to the supply terminations within the pole or pole base.Exception No. 1: No handhole shall be required in a pole 2.5 m (8 ft) or less in height abovegrade where the supply wiring method continues without splice or pull point, and where the interior of the pole and any splices are accessible by removing the luminaire.Exception No. 2: No handhole shall be required in a pole 6.0 m (20 ft) or less in height abovegrade that is provided with a hinged base.Where raceway risers or cable is not installed within the pole, a threaded fitting or nipple shall be brazed, welded, or attached to the pole opposite the handhole for the supply connection.A metal pole shall be provided with an equipment grounding terminal as follows:A pole with a handhole shall have the equipment grounding terminal accessible from the handhole.A pole with a hinged base shall have the equipment grounding terminal accessible within the base.Exception to (3): No grounding terminal shall be required in a pole 2.5 m (8 ft) or less in height abovegrade where the supply wiring method continues without splice or pull, and where the interior of the pole and any splices are accessible by removing the luminaire.A metal pole with a hinged base shall have the hinged base and pole bonded together.Metal raceways or other equipment grounding conductors shall be bonded to the metal pole with an equipment grounding conductor recognized by 250.118 and sized in accordance with 250.122.Conductors in vertical poles used as raceway shall be supported as provided in 300.19.2023: on-disk 2023 rows 410.30(A)-(B) - quoted verbatim
410.30 — Supports (2017, (A)-(B)) 410.30 Supports. (A) General. Luminaires and lampholders shall be securely supported. A luminaire that weighs more than 3 kg (6 lb) or exceeds 400 mm (16 in.) in any dimension shall not be supported by the screw shell of a lampholder. (B) Metal or Nonmetallic Poles Supporting Luminaires. Metal or nonmetallic poles shall be permitted to be used to support luminaires and as a raceway to enclose supply conductors, provided the following conditions are met: (1) A pole shall have a handhole not less than 50 mm x 100 mm (2 in. x 4 in.) with a cover suitable for use in wet locations to provide access to the supply terminations within the pole or pole base. Exception No. 1: No handhole shall be required in a pole 2.5 m (8 ft) or less in height abovegrade where the supply wiring method continues without splice or pull point, and where the interior of the pole and any splices are accessible by removing the luminaire. Exception No. 2: No handhole shall be required in a pole 6.0 m (20 ft) or less in height abovegrade that is provided with a hinged base. (2) Where raceway risers or cable is not installed within the pole, a threaded fitting or nipple shall be brazed, welded, or attached to the pole opposite the handhole for the supply connection. (3) A metal pole shall be provided with an equipment grounding terminal as follows: a. A pole with a handhole shall have the equipment grounding terminal accessible from the handhole. b. A pole with a hinged base shall have the equipment grounding terminal accessible within the base. Exception to (3): No grounding terminal shall be required in a pole 2.5 m (8 ft) or less in height abovegrade where the supply wiring method continues without splice or pull, and where the interior of the pole and any splices are accessible by removing the luminaire. (4) A metal pole with a hinged base shall have the hinged base and pole bonded together. (5) Metal raceways or other equipment grounding conductors shall be bonded to the metal pole with an equipment grounding conductor recognized by 250.118 and sized in accordance with 250.122. (6) Conductors in vertical poles used as raceway shall be supported as provided in 300.19.2017: on-disk NFPA scan §410.30 - quoted verbatim
410.36 — Means of Support (2023, (A)-(G); (A) expanded) Luminaires shall be permitted to be supported by outlet boxes or fittings installed as required by 314.23. The installation shall comply with the following requirements: The outlet boxes or fittings shall comply with 314.27(A)(1) and 314.27(A)(2).Luminaires shall be permitted to be supported in accordance with 314.27(E).Outlet boxes complying with 314.27(E) shall be considered lighting outlets as required by 210.70(A), (B), and (C). Framing members of suspended ceiling systems used to support luminaires shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires shall be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets. Listed clips identified for use with the type of ceiling framing member(s) and luminaire(s) shall also be permitted. Luminaire studs that are not a part of outlet boxes, hickeys, tripods, and crowfeet shall be made of steel, malleable iron, or other material suitable for the application. Insulating joints that are not designed to be mounted with screws or bolts shall have an exterior metal casing, insulated from both screw connections. Raceway fittings used to support a luminaire(s) shall be capable of supporting the weight of the complete fixture assembly and lamp(s). Luminaires shall be permitted to be connected to busways in accordance with 368.17(C). Outdoor luminaires and associated equipment shall be permitted to be supported by trees. Informational Note No. 1: See 225.26 for restrictions for support of overhead conductors. Informational Note No. 2: See 300.5(D) for protection of conductors.2023: on-disk 2023 rows 410.36(A)-(G) - quoted verbatim
410.36 — Means of Support (2017, (A)-(G)) 410.36 Means of Support. (A) Outlet Boxes. Outlet boxes or fittings installed as required by 314.23 and complying with the provisions of 314.27(A) (1) and 314.27(A) (2) shall be permitted to support luminaires. (B) Suspended Ceilings. Framing members of suspended ceiling systems used to support luminaires shall be securely fastened to each other and shall be securely attached to the building structure at appropriate intervals. Luminaires shall be securely fastened to the ceiling framing member by mechanical means such as bolts, screws, or rivets. Listed clips identified for use with the type of ceiling framing member(s) and luminaire(s) shall also be permitted. (C) Luminaire Studs. Luminaire studs that are not a part of outlet boxes, hickeys, tripods, and crowfeet shall be made of steel, malleable iron, or other material suitable for the application. (D) Insulating Joints. Insulating joints that are not designed to be mounted with screws or bolts shall have an exterior metal casing, insulated from both screw connections. (E) Raceway Fittings. Raceway fittings used to support a luminaire(s) shall be capable of supporting the weight of the complete fixture assembly and lamp(s). (F) Busways. Luminaires shall be permitted to be connected to busways in accordance with 368.17(C). (G) Trees. Outdoor luminaires and associated equipment shall be permitted to be supported by trees. Informational Note No. 1: See 225.26 for restrictions for support of overhead conductors. Informational Note No. 2: See 300.5(D) for protection of conductors,2017: on-disk NFPA scan §410.36 - quoted verbatim (the 2017 scan truncates the last Informational Note mid-sentence at "protection of conductors,")
Delta D6 - 410.36(A): outlet-box support expanded — adds 314.27(E) support and the 210.70 lighting-outlet rule - 2017 (A): "Outlet boxes or fittings installed as required by 314.23 and complying with the provisions of 314.27(A)(1) and 314.27(A)(2) shall be permitted to support luminaires." 2023 (A) expands to a three-part rule: outlet boxes/fittings per 314.23; "The installation shall comply with 314.27(A)(1) and 314.27(A)(2)"; "Luminaires shall be permitted to be supported in accordance with 314.27(E)"; and the new "Outlet boxes complying with 314.27(E) shall be considered lighting outlets as required by 210.70(A), (B), and (C)." — this makes a 314.27(E) luminaire box count as a required dwelling lighting outlet. (Machine-verified: "210.70(A), (B), and (C)" present in 2023, absent from 2017.)
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.30 (secure support; >3 kg / >400 mm not on a lampholder screw shell; pole handhole/grounding rules) and 410.36 (B)-(G) (suspended-ceiling framing, luminaire studs, insulating joints, raceway fittings, busways per 368.17(C), trees per 225.26/300.5(D)).
Part V — Grounding (410.40-410.44; 410.46 dropped in 2023)
410.40 — General (2023; EGC rewording) Luminaires and lighting equipment shall be connected to an equipment grounding conductor as required by Part V of this article.2023: on-disk 2023 row 410.40 - quoted verbatim
410.40 — General (2017) 410.40 General. Luminaires and lighting equipment shall be grounded as required in Article 250 and Part V of this article.2017: on-disk NFPA scan §410.40 - quoted verbatim
Delta D7 - 410.40: "grounded as required in Article 250 and Part V" → "connected to an equipment grounding conductor as required by Part V" - 2017: "Luminaires and lighting equipment shall be grounded as required in Article 250 and Part V of this article." 2023: "Luminaires and lighting equipment shall be connected to an equipment grounding conductor as required by Part V of this article." — drops the Article 250 cross-reference and names the equipment grounding conductor specifically. (Machine-verified: "as required in Article 250" present in 2017, absent from 2023; "connected to an equipment grounding conductor" present in 2023.)
410.42 — Exposed Conductive Surfaces (2023; the rewrite + 3 exceptions) Exposed conductive surfaces shall be connected to an equipment grounding conductor. Exception: Exposed conductive surfaces that comply with any of the following shall not be required to be connected to an equipment grounding conductor: (1) Surfaces separated from all live parts by a listed system of double insulation (2) Surfaces on small isolated parts, such as mounting screws, clips, and decorative bands on glass spaced at least 38 mm (11/2 in.) from lamp terminals (3) Surfaces on portable luminaires with a polarized attachment plug2023: on-disk 2023 row 410.42 - quoted verbatim
410.42 — Luminaire(s) with Exposed Conductive Parts (2017; OCR "1% in.") 410.42 Luminaire(s) with Exposed Conductive Parts. Exposed metal parts shall be connected to an equipment grounding conductor or insulated from the equipment grounding conductor and other conducting surfaces or be inaccessible to unqualified personnel. Lamp tie wires, mounting screws, clips, and decorative bands on glass spaced at least 38 mm (1% in.) from lamp terminals shall not be required to be grounded.2017: on-disk NFPA scan §410.42 - quoted verbatim (disclosed in Sources: "38 mm (1% in.)" is a scan misread of "38 mm (1½ in.)")
Delta D8 - 410.42: a full rewrite — "exposed metal parts... or insulated... or inaccessible" becomes "exposed conductive surfaces shall be connected to an EGC" + 3 exceptions - 2017: "Exposed metal parts shall be connected to an equipment grounding conductor or insulated from the equipment grounding conductor and other conducting surfaces or be inaccessible to unqualified personnel. Lamp tie wires, mounting screws, clips, and decorative bands on glass spaced at least 38 mm (1½ in.) from lamp terminals shall not be required to be grounded." 2023: "Exposed conductive surfaces shall be connected to an equipment grounding conductor," with an Exception for surfaces that: (1) are separated from all live parts by a listed system of double insulation; (2) are on small isolated parts such as mounting screws, clips, and decorative bands on glass spaced ≥38 mm (1½ in.) from lamp terminals; (3) are on portable luminaires with a polarized attachment plug. The 2017 "insulated or inaccessible" alternative is gone — 2023 requires the EGC connection unless one of the three exceptions applies. (Mike Holt 2023 documents this: "This section was condensed into parent text and an Exception, and the title was changed to reflect the new content.")
410.44 — Methods of Grounding (2023; exceptions renumbered) Luminaires and equipment that require connection to an equipment grounding conductor in accordance with 410.42 shall be mechanically connected to an equipment grounding conductor. Exception No. 1: Replacement luminaires shall be permitted to connect an equipment grounding conductor in the same manner as replacement receptacles in compliance with 250.130(C). The luminaire shall then comply with 410.42. Exception No. 2: Where no equipment grounding conductor exists at the outlet, replacement luminaires that are GECI protected or do not have exposed conductive parts shall not be required to be connected to an equipment grounding conductor.2023: on-disk 2023 row 410.44 - quoted verbatim (the 2023 dataset prints "GECI" — a variant of "GFCI")
410.44 — Methods of Grounding (2017, 3 exceptions) 410.44 Methods of Grounding. Luminaires and equipment shall be mechanically connected to an equipment grounding conductor as specified in 250.118 and sized in accordance with 250.122. Exception No. 1: Luminaires made of insulating material that is directly wired or attached to outlets supplied by a wiring method that does not provide a ready means for grounding attachment to an equipment grounding conductor shall be made of insulating material and shall have no exposed conductive parts. Exception No. 2: Replacement luminaires shall be permitted to connect an equipment grounding conductor from the outlet in compliance with 250.130(C). The luminaire shall then comply with 410.42. Exception No. 3: Where no equipment grounding conductor exists at the outlet, replacement luminaires that are GFCI protected shall not be required to be connected to an equipment grounding conductor.2017: on-disk NFPA scan §410.44 - quoted verbatim
Delta D9 - 410.44: the 250.118/250.122 cite is dropped, the three exceptions collapse to two, and "GFCI" appears as "GECI" in the 2023 dataset - 2017 opens "shall be mechanically connected to an equipment grounding conductor as specified in 250.118 and sized in accordance with 250.122" and carries three exceptions (insulating-material luminaire; replacement per 250.130(C); GFCI-protected replacement). 2023 drops the 250.118/250.122 cite, scopes the rule to "Luminaires and equipment that require connection... in accordance with 410.42," and carries two exceptions (replacement per 250.130(C) "in the same manner as replacement receptacles"; and replacement luminaires that are GFCI-protected or do not have exposed conductive parts). The 2023 dataset renders the protection acronym as "GECI" (a variant of "GFCI") — flagged as an on-disk dataset artifact, not a code term. (Machine-verified: "250.118" present in 2017, absent from 2023; "GECI" present in 2023.)
410.46 — Equipment Grounding Conductor Attachment (2017 ONLY — dropped in 2023) 410.46 Equipment Grounding Conductor Attachment. Luminaires with exposed metal parts shall be provided with a means for connecting an equipment grounding conductor for such luminaires.2017: on-disk NFPA scan §410.46 - quoted verbatim (NO 2023 counterpart — see D10)
Delta D10 - 410.46: DROPPED in 2023 — the EGC-attachment rule is folded into the rewritten 410.42 / 410.44 - 2017 410.46: "Luminaires with exposed metal parts shall be provided with a means for connecting an equipment grounding conductor for such luminaires." In 2023 there is no 410.46 row. The substance — exposed conductive parts must be connectable to an EGC — is absorbed into the rewritten 410.42 (exposed conductive surfaces shall be connected to an EGC, with the three exceptions) and 410.44 (the mechanical-connection methods + replacement-luminaire exceptions). (Machine-verified: "410.46" has no on-disk 2023 row; the "means for connecting an equipment grounding conductor" sentence is absent from the 2023 dataset; 2023 Part V runs 410.40-410.44 only.)
Part VI — Wiring of Luminaires (410.50-410.71; +410.69, +410.71 NEW; 410.48→50, 410.50→51 renumbered)
410.50 — Luminaire Wiring, General (2023; was 2017 410.48) Wiring on or within luminaires shall be neatly arranged and shall not be exposed to physical damage. Excess wiring shall be avoided. Conductors shall be arranged so that they are not subjected to temperatures above those for which they are rated.2023: on-disk 2023 row 410.50 - quoted verbatim (renumbered from 2017 410.48; word-identical)
410.48 — Luminaire Wiring, General (2017; → 2023 410.50) 410.48 Luminaire Wiring — General. Wiring on or within luminaires shall be neatly arranged and shall not be exposed to physical damage. Excess wiring shall be avoided. Conductors shall be arranged so that they are not subjected to temperatures above those for which they are rated.2017: on-disk NFPA scan §410.48 - quoted verbatim
410.51 — Polarization of Luminaires (2023; was 2017 410.50) Luminaires shall be wired so that the screw shells of lampholders are connected to the same luminaire or circuit conductor or terminal. The grounded conductor, where connected to a screw shell lampholder, shall be connected to the screw shell.2023: on-disk 2023 row 410.51 - quoted verbatim (renumbered from 2017 410.50; word-identical)
410.50 — Polarization of Luminaires (2017; → 2023 410.51) 410.50 Polarization of Luminaires. Luminaires shall be wired so that the screw shells of lampholders are connected to the same luminaire or circuit conductor or terminal. The grounded conductor, where connected to a screw shell lampholder, shall be connected to the screw shell.2017: on-disk NFPA scan §410.50 - quoted verbatim
410.52 — Conductor Insulation (2023; Info Note now cites 402.3/402.5/402.6) Luminaires shall be wired with conductors having insulation suitable for the environmental conditions, current, voltage, and temperature to which the conductors will be subjected. Informational Note: See 402.3, 402.5, and 402.6 for ampacity of fixture wire, maximum operating temperature, voltage limitations, and minimum wire size.2023: on-disk 2023 row 410.52 - quoted verbatim
410.52 — Conductor Insulation (2017; Info Note cites "Article 402") 410.52 Conductor Insulation. Luminaires shall be wired with conductors having insulation suitable for the environmental conditions, current, voltage, and temperature to which the conductors will be subjected. Informational Note: For ampacity of fixture wire, maximum operating temperature, voltage limitations, minimum wire size, and other information, see Article 402.2017: on-disk NFPA scan §410.52 - quoted verbatim
Delta D11 - 410.52: the Informational Note pinpoints the Article 402 sections (402.3, 402.5, 402.6) - 2017 Info Note: "For ampacity of fixture wire, maximum operating temperature, voltage limitations, minimum wire size, and other information, see Article 402." 2023 Info Note: "See 402.3, 402.5, and 402.6 for ampacity of fixture wire, maximum operating temperature, voltage limitations, and minimum wire size." — same content, the cite is now section-specific. (Machine-verified: "402.3, 402.5, and 402.6" present in 2023; "see Article 402" present in 2017.)
410.54 — Pendant Conductors for Incandescent Filament Lamps (2023, (A)-(C)) Pendant lampholders with permanently attached leads, where used for other than festoon wiring, shall be hung from separate stranded rubber-covered conductors that are soldered directly to the circuit conductors but supported independently thereof. Unless part of listed decorative lighting assemblies, pendant conductors shall not be smaller than 14 AWG for mogul-base or medium-base screw shell lampholders or smaller than 18 AWG for intermediate or candelabra-base lampholders. Pendant conductors longer than 900 mm (3 ft) shall be twisted together where not cabled in a listed assembly.2023: on-disk 2023 rows 410.54(A)-(C) - quoted verbatim
410.54 — Pendant Conductors (2017, (A)-(C)) 410.54 Pendant Conductors for Incandescent Filament Lamps. (A) Support. Pendant lampholders with permanently attached leads, where used for other than festoon wiring, shall be hung from separate stranded rubber-covered conductors that are soldered directly to the circuit conductors but supported independently thereof. (B) Size. Unless part of listed decorative lighting assemblies, pendant conductors shall not be smaller than 14 AWG for mogul-base or medium-base screw shell lampholders or smaller than 18 AWG for intermediate or candelabra-base lampholders. (C) Twisted or Cabled. Pendant conductors longer than 900 mm (3 ft) shall be twisted together where not cabled in a listed assembly.2017: on-disk NFPA scan §410.54 - quoted verbatim
410.56 — Protection of Conductors and Insulation (2023, (A)-(F)) Conductors shall be secured in a manner that does not tend to cut or abrade the insulation. Conductor insulation shall be protected from abrasion where it passes through metal. Splices and taps shall not be located within luminaire arms or stems. No unnecessary splices or taps shall be made within or on a luminaire. Informational Note: See 110.14 for approved means of making connections. Stranded conductors shall be used for wiring on luminaire chains and on other movable or flexible parts. Conductors shall be arranged so that the weight of the luminaire or movable parts does not put tension on the conductors.2023: on-disk 2023 rows 410.56(A)-(F) - quoted verbatim
410.56 — Protection of Conductors and Insulation (2017, (A)-(F)) 410.56 Protection of Conductors and Insulation. (A) Properly Secured. Conductors shall be secured in a manner that does not tend to cut or abrade the insulation. (B) Protection Through Metal. Conductor insulation shall be protected from abrasion where it passes through metal. (C) Luminaire Stems. Splices and taps shall not be located within luminaire arms or stems. (D) Splices and Taps. No unnecessary splices or taps shall be made within or on a luminaire. Informational Note: For approved means of making connections, see 110.14. (E) Stranding. Stranded conductors shall be used for wiring on luminaire chains and on other movable or flexible parts. (F) Tension. Conductors shall be arranged so that the weight of the luminaire or movable parts does not put tension on the conductors.2017: on-disk NFPA scan §410.56 - quoted verbatim
Delta D31 - 410.56: the Informational Note is reworded (the "see 110.14" moves to the front) - 2017: "Informational Note: For approved means of making connections, see 110.14." 2023: "Informational Note: See 110.14 for approved means of making connections." — the same 110.14 cite, reworded; the (A)-(F) protection provisions are unchanged. (Machine-verified: both editions cite 110.14; only the sentence order differs.)
410.59 — Cord-Connected Showcases (2023, intro + (A)-(E)) Individual showcases, other than fixed, shall be permitted to be connected by flexible cord to permanently installed receptacles, and groups of not more than six such showcases shall be permitted to be coupled together by flexible cord and separable locking-type connectors with one of the group connected by flexible cord to a permanently installed receptacle. The installation shall comply with 410.59(A) through (E). Flexible cord shall be of the hard-service type, having conductors not smaller than the branch-circuit conductors, having ampacity at least equal to the branch-circuit overcurrent device, and having an equipment grounding conductor. Informational Note: See Table 250.122 for size of equipment grounding conductor. Receptacles, connectors, and attachment plugs shall be of a listed grounding type rated 15 or 20 amperes. Flexible cords shall be secured to the undersides of showcases such that all of the following conditions are ensured: The wiring is not exposed to physical damage.The separation between cases is not in excess of 50 mm (2 in.), or more than 300 mm (12 in.) between the first case and the supply receptacle.The free lead at the end of a group of showcases has a female fitting not extending beyond the case. Equipment other than showcases shall not be electrically connected to showcases. Where showcases are cord-connected, the secondary circuit(s) of each electric-discharge lighting ballast shall be limited to one showcase.2023: on-disk 2023 rows 410.59 + (A)-(E) - quoted verbatim
410.59 — Cord-Connected Showcases (2017, intro + (A)-(E); OCR "Cord-Gonnected") 410.59 Cord-Gonnected Showcases. Individual showcases, other than fixed, shall be permitted to be connected by flexible cord to permanently installed receptacles, and groups of not more than six such showcases shall be permitted to be coupled together by flexible cord and separable locking-type connectors with one of the group connected by flexible cord to a permanently installed receptacle. The installation shall comply with 410.59(A) through (E). (A) Cord Requirements. Flexible cord shall be of the hardservice type, having conductors not smaller than the branchcircuit conductors, having ampacity at least equal to the branch-circuit overcurrent device, and having an equipment grounding conductor. Informational Note: See Table 250.122 for size of equipment grounding conductor. (B) Receptacles, Connectors, and Attachment Plugs. Receptacles, connectors, and attachment plugs shall be of a listed grounding type rated 15 or 20 amperes. (C) Support. Flexible cords shall be secured to the undersides of showcases such that all of the following conditions are ensured: (1) The wiring is not exposed to physical damage. (2) The separation between cases is not in excess of 50 mm (2 in.), or more than 300 mm (12 in.) between the first case and the supply receptacle. (3) The free lead at the end of a group of showcases has a female fitting not extending beyond the case. (D) No Other Equipment. Equipment other than showcases shall not be electrically connected to showcases. (E) Secondary Circuit(s). Where showcases are cordconnected, the secondary circuit(s) of each electric-discharge lighting ballast shall be limited to one showcase.2017: on-disk NFPA scan §410.59 - quoted verbatim (disclosed in Sources: the 2017 heading prints "Cord-Gonnected" — an OCR misread of "Cord-Connected")
410.62 — Cord-Connected Lampholders and Luminaires (2023, (A)-(C)) Where a metal lampholder is attached to a flexible cord, the inlet shall be equipped with an insulating bushing that, if threaded, is not smaller than metric designator 12 (trade size 3/8). The cord hole shall be of a size appropriate for the cord, and all burrs and fins shall be removed in order to provide a smooth bearing surface for the cord. Bushing having holes 7 mm (9/32 in.) in diameter shall be permitted for use with plain pendant cord and holes 11 mm (13/32 in.) in diameter with reinforced cord. Luminaires that require adjusting or aiming after installation shall not be required to be equipped with an attachment plug or cord connector, provided the exposed cord is suitable for hard-usage or extra-hard-usage and is not longer than that required for maximum adjustment. The cord shall not be subject to strain or physical damage. Informational Note: See Table 400.4, "Use" column for application provisions. Electric-discharge and LED luminaires shall comply with 410.62(C)(1), (C)(2), and (C)(3), as applicable. A luminaire or a listed assembly in compliance with any of the conditions in 410.62(C)(1)(a) through (C)(1)(c) shall be permitted to be cord connected provided the luminaire is located directly below the outlet or busway, the cord is not subject to strain or physical damage, and the cord is visible over its entire length except at terminations. Informational Note: See 400.10, Uses Permitted, and 400.12, Uses Not Permitted.A luminaire shall be permitted to be connected with a cord terminating in a grounding-type attachment plug or busway plug. If grounding is not required in accordance with 410.42, a polarized-type plug shall be permitted.A luminaire assembly equipped with a strain relief and canopy shall be permitted to use a cord connection between the luminaire assembly and the canopy. The canopy shall be permitted to include a section of raceway not over 150 mm (6 in.) in length and intended to facilitate the connection to an outlet box mounted above a suspended ceiling.Listed luminaires connected using listed assemblies that incorporate manufactured wiring system connectors in accordance with 604.100(C) shall be permitted to be cord connected. Electric-discharge luminaires provided with mogul-base, screw shell lampholders shall be permitted to be connected to branch circuits of 50 amperes or less by cords complying with 240.5. Receptacles and attachment plugs shall be permitted to be of a lower ampere rating than the branch circuit but not less than 125 percent of the luminaire full-load current. Electric-discharge luminaires equipped with a flanged surface inlet shall be permitted to be supplied by cord pendants equipped with cord connectors. Inlets and connectors shall be permitted to be of a lower ampere rating than the branch circuit but not less than 125 percent of the luminaire load current.2023: on-disk 2023 rows 410.62(A)-(C)(3) - quoted verbatim
410.62 — Cord-Connected Lampholders and Luminaires (2017, (A)-(C); OCR bushing fractions) 410.62 Cord-Connected Lampholders and Luminaires. (A) Lampholders. Where a metal lampholder is attached to a flexible cord, the inlet shall be equipped with an insulating bushing that, if threaded, is not smaller than metric designator 12 (trade size %) pipe size. The cord hole shall be of a size appropriate for the cord, and all burrs and fins shall be removed in order to provide a smooth bearing surface for the cord, Bushing having holes 7 mm (%: in.) in diameter shall be permitted for use with plain pendant cord and holes 11 mm ('%p» in.) in diameter with reinforced cord. (B) Adjustable Luminaires. Luminaires that require adjusting or aiming after installation shall not be required to be equipped with an attachment plug or cord connector, provided the exposed cord is suitable for hard-usage or extra-hard-usage and is not longer than that required for maximum adjustment. The cord shall not be subject to strain or physical damage. Informational Note: For application provisions, see Table 400.4, “Use” column. (C) Electric-Discharge and LED Luminaires. Electricdischarge and LED luminaires shall comply with (1), (2), and (3) as applicable. (1) Cord-Connected Installation. A luminaire or a listed assembly in compliance with any of the conditions in (a) through (c) shall be permitted to be cord connected provided the luminaire is located directly below the outlet or busway, the cord is not subject to strain or physical damage, and the cord is visible over its entire length except at terminations. (a) A luminaire shall be permitted to be connected with a cord terminating in a grounding-type attachment plug or busway plug. (b) A luminaire assembly equipped with a strain relief and canopy shall be permitted to use a cord connection between the luminaire assembly and the canopy. The canopy shall be permitted to include a section of raceway not over 150 mm. (6 in.) in length and intended to facilitate the connection to an outlet box mounted above a suspended ceiling. (c) Listed luminaires connected using listed assemblies that incorporate manufactured wiring system connectors in accordance with 604.100(C) shall be permitted to be cord connected. (2) Provided with Mogul-Base, Screw Shell Lampholders. Electric-discharge luminaires provided with mogul-base, screw shell lampholders shall be permitted to be connected to branch circuits of 50 amperes or less by cords complying with 240.5. Receptacles and attachment plugs shall be permitted to be of a lower ampere rating than the branch circuit but not less than 125 percent of the luminaire full-load current. (3) Equipped with Flanged Surface Inlet. Electric-discharge luminaires equipped with a flanged surface inlet shall be permitted to be supplied by cord pendants equipped with cord connectors. Inlets and connectors shall be permitted to be of a lower ampere rating than the branch circuit but not less than 125 percent of the luminaire load current.2017: on-disk NFPA scan §410.62 - quoted verbatim (disclosed in Sources: the 2017 scan bushing-hole fractions print as OCR garbage — 2023 resolves them to 9/32 in. and 13/32 in.)
Delta D12 - 410.62(C)(1): restructured to (C)(1)(a)-(c); adds the 400.10/400.12 note and a polarized-plug allowance - 2023 (C) now points to "410.62(C)(1), (C)(2), and (C)(3)" with (C)(1) broken into (a) grounding-type or busway plug, (b) strain-relief/canopy assembly, (c) manufactured wiring-system connectors per 604.100(C). Two 2023 additions: an Informational Note "See 400.10, Uses Permitted, and 400.12, Uses Not Permitted," and (C)(1)(a) "If grounding is not required in accordance with 410.42, a polarized-type plug shall be permitted." The 2017 (A) bushing-hole fractions print as OCR garbage in the scan (the 2023 CSV resolves them: 7 mm (9/32 in.) and 11 mm (13/32 in.)). (Machine-verified: "a polarized-type plug shall be permitted" present in 2023, absent from 2017.)
410.64 — Luminaires as Raceways (2023, intro + (A)-(C)) Luminaires shall not be used as a raceway for circuit conductors unless they comply with 410.64(A), (B), or (C). Luminaires listed and marked for use as a raceway shall be permitted to be used as a raceway. Luminaires identified for through-wiring, as permitted by 410.21, shall be permitted to be used as a raceway. Luminaires designed for end-to-end connection to form a continuous assembly, or luminaires connected together by recognized wiring methods, shall be permitted to contain the conductors of a 2-wire branch circuit, or one multiwire branch circuit, supplying the connected luminaires and shall not be required to be listed as a race-way. One additional 2-wire branch circuit separately supplying one or more of the connected luminaires shall also be permitted. Informational Note: See Article 100 for the definition of Multiwire Branch Circuit.2023: on-disk 2023 rows 410.64 + (A)-(C) - quoted verbatim
410.64 — Luminaires as Raceways (2017, intro + (A)-(C)) 410.64 Luminaires as Raceways. Luminaires shall not be used as a raceway for circuit conductors unless they comply with 410.64(A), (B), or (C). (A) Listed. Luminaires listed and marked for use as a raceway shall be permitted to be used as a raceway. (B) Through-Wiring. Luminaires identified for throughwiring, as permitted by 410.21, shall be permitted to be used as a raceway. (C) Luminaires Connected Together. Luminaires designed for end-to-end connection to form a continuous assembly, or luminaires connected together by recognized wiring methods, shall be permitted to contain the conductors of a 2-wire branch circuit, or one multiwire branch circuit, supplying the connected luminaires and shall not be required to be listed as a raceway. One additional 2-wire branch circuit separately supplying one or more of the connected luminaires shall also be permitted. Informational Note: See Article 100 for the definition of Multiwire Branch Circuit.2017: on-disk NFPA scan §410.64 - quoted verbatim
410.68 — Feeder and Branch-Circuit Conductors and Ballasts (2023) Feeder and branch-circuit conductors within 75 mm (3 in.) of a ballast, LED driver, power supply, or transformer shall have an insulation temperature rating not lower than 90°C (194°F), unless supplying a luminaire marked as suitable for a different insulation temperature.2023: on-disk 2023 row 410.68 - quoted verbatim
410.68 — Feeder and Branch-Circuit Conductors and Ballasts (2017; OCR "ofa ballast") 410.68 Feeder and Branch-Circuit Conductors and Ballasts. Feeder and branch-circuit conductors within 75 mm (3 in.) ofa ballast, LED driver, power supply, or transformer shall have an insulation temperature rating not lower than 90°C (194°F), unless supplying a luminaire marked as suitable for a different insulation temperature.2017: on-disk NFPA scan §410.68 - quoted verbatim (disclosed in Sources: "within 75 mm (3 in.) ofa ballast" — a scan run-together of "of a ballast")
410.69 — Control Conductor Color (NEW in 2023) Where control conductors are spliced, terminated, or connected in the same luminaire or enclosure as the branch-circuit conductors, the field-connected control conductor shall not be of a color reserved for the grounded branch-circuit conductor or the equipment grounding conductor. Informational Note: See 200.6 for identification of grounded conductor and 250.119 for identification of equipment grounding conductor. Exception: A field-connected gray-colored control conductor shall be permitted if the insulation is permanently re-identified by marking tape, painting, or other effective means at its termination and at each location where the conductor is visible and accessible. Identification shall encircle the insulation and shall be a color other than white, gray, or green.2023: on-disk 2023 row 410.69 - quoted verbatim (NO 2017 counterpart)
Delta D13 - 410.69: NEW in 2023 — field-connected control conductors must not use the grounded/EGC colors (gray re-ID exception) - Entirely new in 2023: where control conductors are spliced/terminated/connected in the same luminaire or enclosure as the branch-circuit conductors, the field-connected control conductor "shall not be of a color reserved for the grounded branch-circuit conductor or the equipment grounding conductor" (see 200.6 / 250.119), with an Exception permitting a field-connected gray control conductor if permanently re-identified (marking tape/painting) at its termination and each visible location, encircling the insulation, in a color other than white, gray, or green. (Machine-verified: "410.69" has no on-disk 2017 section.)
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.50 (was 410.48: wiring neatly arranged, no physical damage, temperature limit), 410.51 (was 410.50: screw-shell polarization), 410.54 (pendant conductors 14/18 AWG min, 900 mm twist), 410.59 (cord-connected showcases, (A)-(E)), 410.64 (luminaires as raceways (A)-(C)), and 410.68 (75 mm / 90 °C ballast rule). 410.56 is not in this set — its Informational Note is reworded in 2023 (D31).
410.70 — Combustible Shades and Enclosures (2023; "Air space") Air space shall be provided between lamps and shades or other enclosures of combustible material.2023: on-disk 2023 row 410.70 - quoted verbatim
410.70 — Combustible Shades and Enclosures (2017; "Adequate airspace") 410.70 Combustible Shades and Enclosures. Adequate airspace shall be provided between lamps and shades or other enclosures of combustible material.2017: on-disk NFPA scan §410.70 - quoted verbatim
Delta D14 - 410.70: "Adequate airspace" → "Air space" (wording) - 2017: "Adequate airspace shall be provided between lamps and shades or other enclosures of combustible material." 2023: "Air space shall be provided between lamps and shades or other enclosures of combustible material." — editorial reword, same requirement. (Machine-verified: "Adequate airspace" present in 2017; "Air space shall be provided" present in 2023.)
410.71 — Disconnecting Means for Double-Ended-Lamp Fluorescent/LED Luminaires (NEW in 2023, relocated from 410.130(G)) In indoor locations other than dwellings and associated accessory structures, fluorescent or LED luminaires that utilize double-ended lamps and contain ballast(s) or LED driver(s) that can be serviced in place shall have a disconnecting means either internal or external to each luminaire. For existing installed luminaires without disconnecting means, at the time a ballast or LED driver is added or replaced a disconnecting means shall be installed. The line side terminals of the disconnecting means shall be guarded. Exception No. 1: A disconnecting means shall not be required for luminaires installed in hazardous (classified) location(s). Exception No. 2: A disconnecting means shall not be required for luminaires that provide emergency illumination required in 700.16. Exception No. 3: For cord-and-plug-connected luminaires, an accessible separable connector or an accessible plug and receptacle shall be permitted to serve as the disconnecting means. Exception No. 4: Disconnecting means shall not be required for every luminaire in a building area if all of the following conditions apply: (1) More than one luminaire is installed in the building area (2) The luminaires are not connected to a multiwire branch circuit (3) The design of the installation includes disconnecting means (4) The building area will not be left in total darkness should only one disconnect be opened When connected to multiwire branch circuits, the disconnecting means shall simultaneously break all the supply conductors to the ballast, including the grounded conductor. The disconnecting means shall be located so as to be accessible to qualified persons before servicing or maintaining the ballast. Where the disconnecting means is external to the luminaire, it shall be a single device, and it shall be attached to the luminaire or the luminaire shall be located within sight of the disconnecting means.2023: on-disk 2023 rows 410.71(1)-(3) - quoted verbatim (NO 2017 counterpart at 410.71; content relocated from 2017 410.130(G))
Delta D15 - 410.71: NEW section — the 410.130(G) disconnecting-means rule is relocated here and extended to LED luminaires - 2017 carried this rule at 410.130(G) (Disconnecting Means — General / Multiwire / Location) for "fluorescent luminaires that utilize double-ended lamps." 2023 moves it to a standalone 410.71 in Part VI (Wiring) and broadens the scope to "fluorescent or LED luminaires that utilize double-ended lamps and contain ballast(s) or LED driver(s) that can be serviced in place." The four exceptions (hazardous locations; 700.16 emergency; cord-and-plug accessible separable connector/plug; multi-luminaire no-total-darkness design) and the multiwire/location rules carry over. (Mike Holt 2023 documents this: "This rule was relocated here from 410.130(G) since LEDs fall under the scope of Part VI of Article 410.") (Machine-verified: "410.71" has no 2017 section; 2017 410.130 carries the "(G) Disconnecting Means" text, 2023 410.130 does not.)
Part VII — Construction of Luminaires (410.70-410.84; 410.74→410.80 renumbered)
410.80 — Luminaire Rating / Markings (2023; was 2017 410.74) All luminaires shall be marked with the maximum lamp wattage or electrical rating, manufacturer's name, trademark, or other suitable means of identification. A luminaire requiring supply wire rated higher than 60°C (140°F) shall be marked with the minimum supply wire temperature rating on the luminaire and shipping carton or equivalent. The electrical rating shall include the voltage and frequency and shall indicate the current rating of the unit, including the ballast, transformer, LED driver, power supply, or autotransformer.2023: on-disk 2023 rows 410.80(A)-(B) - quoted verbatim (renumbered from 2017 410.74)
410.74 — Luminaire Rating (2017; → 2023 410.80) 410.74 Luminaire Rating. (A) Marking. All luminaires shall be marked with the maximum lamp wattage or electrical rating, manufacturer’s name, trademark, or other suitable means of identification. A luminaire requiring supply wire rated higher than 60°C (140°F) shall be marked with the minimum supply wire temperature rating on the luminaire and shipping carton or equivalent. (B) Electrical Rating. The electrical rating shall include the voltage and frequency and shall indicate the current rating of the unit, including the ballast, transformer, LED driver, power supply, or autotransformer.2017: on-disk NFPA scan §410.74 - quoted verbatim
Delta D16 - 410.74 → 410.80: renumbered (the (A) marking / (B) electrical-rating content carries over) - 2017 410.74 (Luminaire Rating, (A) Marking + (B) Electrical Rating) is renumbered 410.80 in 2023. The content — all luminaires marked with max lamp wattage or electrical rating, manufacturer name/trademark, the 60 °C supply-wire marking, and the voltage/frequency/current electrical rating — is re-flowed but substantively the same. (The renumbering opens the 410.71 slot for the relocated disconnecting-means rule, see D15.)
410.82 — Portable Luminaires (2023; (B) Portable Handlamps deleted) Portable luminaires shall be wired with flexible cord recognized by 400.4 and an attachment plug of the polarized or grounding type. If used with Edison-base lampholders, the grounded conductor shall be identified and attached to the screw shell and the identified blade of the attachment plug.2023: on-disk 2023 row 410.82 - quoted verbatim
410.82 — Portable Luminaires (2017, (A) General + (B) Portable Handlamps) 410.82 Portable Luminaires. (A) General. Portable luminaires shall be wired with flexible cord recognized by 400.4 and an attachment plug of the polarized or grounding type. Where used with Edison-base lampholders, the grounded conductor shall be identified and attached to the screw shell and the identified blade of the attachment plug. (B) Portable Handlamps. In addition to the provisions of 410.82(A), portable handlamps shall comply with the following: (1) Metal shell, paper-lined lampholders shall not be used. (2) Handlamps shall be equipped with a handle of molded composition or other insulating material. (3) Handlamps shall be equipped with a substantial guard attached to the lampholder or handle. (4) Metallic guards shall be grounded by means of an equipment grounding conductor run with circuit conductors within the power-supply cord. (5) Portable handlamps shall not be required to be grounded where supplied through an isolating transformer with an ungrounded secondary of not over 50 volts.2017: on-disk NFPA scan §410.82 - quoted verbatim (2017 (B) carries five portable-handlamp provisions that 2023 deletes)
Delta D17 - 410.82: the 2017 (B) Portable Handlamps provision (5 rules) is deleted in 2023 - 2017 410.82(B) "Portable Handlamps" required, in addition to (A): (1) no metal-shell paper-lined lampholders; (2) a molded-composition or insulating handle; (3) a substantial guard; (4) metallic guards grounded by an EGC in the power-supply cord; (5) no grounding required when supplied through an isolating transformer with an ungrounded secondary ≤50 V. In 2023, 410.82 is down to the single (A) rule (flexible cord per 400.4 + polarized/grounding attachment plug; Edison-base grounded-conductor rule). The portable-handlamp-specific provisions are gone from 410.82. (Machine-verified: "Portable Handlamps" present in 2017 410.82, absent from 2023 410.82; "metal shell, paper-lined lampholders" present in 2017, absent from 2023.)
410.84 — Cord Bushings (2023) A bushing or the equivalent shall be provided where flexible cord enters the base or stem of a portable luminaire. The bushing shall be of insulating material unless a jacketed type of cord is used.2023: on-disk 2023 row 410.84 - quoted verbatim
410.84 — Cord Bushings (2017) 410.84 Cord Bushings. A bushing or the equivalent shall be provided where flexible cord enters the base or stem of a portable luminaire. The bushing shall be of insulating material unless a jacketed type of cord is used.2017: on-disk NFPA scan §410.84 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.84 (bushing/equivalent where cord enters the base or stem; insulating material unless jacketed cord).
Part VIII — Installation of Lampholders (410.90-410.97)
410.90 — Screw Shell Type (2023) Lampholders of the screw shell type shall be installed for use as lampholders only. Where supplied by a circuit having a grounded conductor, the grounded conductor shall be connected to the screw shell.2023: on-disk 2023 row 410.90 - quoted verbatim
410.90 — Screw Shell Type (2017) 410.90 Screw Shell Type. Lampholders of the screw shell type shall be installed for use as lampholders only. Where supplied by a circuit having a grounded conductor, the grounded conductor shall be connected to the screw shell.2017: on-disk NFPA scan §410.90 - quoted verbatim
410.93 — Double-Pole Switched Lampholders (2023) Where supplied by the ungrounded conductors of a circuit, the switching device of lampholders of the switched type shall simultaneously disconnect both conductors of the circuit.2023: on-disk 2023 row 410.93 - quoted verbatim
410.93 — Double-Pole Switched Lampholders (2017) 410.93 Double-Pole Switched Lampholders. Where supplied by the ungrounded conductors of a circuit, the switching device of lampholders of the switched type shall simultaneously disconnect both conductors of the circuit.2017: on-disk NFPA scan §410.93 - quoted verbatim
410.96 — Lampholders in Wet or Damp Locations (2023) Lampholders installed in wet locations shall be listed for use in wet locations. Lampholders installed in damp locations shall be listed for damp locations or shall be listed for wet locations.2023: on-disk 2023 row 410.96 - quoted verbatim
410.96 — Lampholders in Wet or Damp Locations (2017) 410.96 Lampholders in Wet or Damp Locations. Lampholders installed in wet locations shall be listed for use in wet locations. Lampholders installed in damp locations shall be listed for damp locations or shall be listed for wet locations.2017: on-disk NFPA scan §410.96 - quoted verbatim
410.97 — Lampholders Near Combustible Material (2023) Lampholders shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of 90°C (194°F).2023: on-disk 2023 row 410.97 - quoted verbatim
410.97 — Lampholders Near Combustible Material (2017) 410.97 Lampholders Near Combustible Material. Lampholders shall be constructed, installed, or equipped with shades or guards so that combustible material is not subjected to temperatures in excess of 90°C (194°F).2017: on-disk NFPA scan §410.97 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.90 (screw-shell lampholders; grounded conductor to screw shell), 410.93 (double-pole switched lampholders), 410.96 (wet/damp listing), and 410.97 (no combustible material above 90 °C).
Part IX — Lamps and Auxiliary Equipment (410.100-410.104; 410.103→410.100 renumbered)
410.100 — Bases, Incandescent Lamps (2023; was 2017 410.103) An incandescent lamp for general use on lighting branch circuits shall not be equipped with a medium base if rated over 300 watts, or with a mogul base if rated over 1500 watts. Special bases or other devices shall be used for over 1500 watts.2023: on-disk 2023 row 410.100 - quoted verbatim (renumbered from 2017 410.103; word-identical)
410.103 — Bases, Incandescent Lamps (2017; → 2023 410.100) 410.103 Bases, Incandescent Lamps. An incandescent lamp for general use on lighting branch circuits shall not be equipped with a medium base if rated over 300 watts, or with a mogul base if rated over 1500 watts. Special bases or other devices shall be used for over 1500 watts.2017: on-disk NFPA scan §410.103 - quoted verbatim
410.104 — Electric-Discharge Lamp Auxiliary Equipment (2023, (A)-(B)) Auxiliary equipment for electric-discharge lamps shall be enclosed in noncombustible cases and treated as sources of heat. Where supplied by the ungrounded conductors of a circuit, the switching device of auxiliary equipment shall simultaneously disconnect all conductors.2023: on-disk 2023 rows 410.104(A)-(B) - quoted verbatim
410.104 — Electric-Discharge Lamp Auxiliary Equipment (2017, (A)-(B)) 410.104 Electric-Discharge Lamp Auxiliary Equipment. (A) Enclosures. Auxiliary equipment for electric-discharge lamps shall be enclosed in noncombustible cases and treated as sources of heat. (B) Switching. Where supplied by the ungrounded conductors of a circuit, the switching device of auxiliary equipment shall simultaneously disconnect all conductors.2017: on-disk NFPA scan §410.104 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.100 (was 410.103: incandescent base limits — medium ≤300 W, mogul ≤1500 W, special bases over) and 410.104 (auxiliary equipment enclosed in noncombustible cases + treated as heat sources; switching disconnects all conductors).
Part X — Special Provisions for Flush and Recessed Luminaires (410.110-410.117)
410.110 — General (2023; "410.115 through 410.126") Luminaires installed in recessed cavities in walls or ceilings, including suspended ceilings, shall comply with 410.115 through 410.126.2023: on-disk 2023 row 410.110 - quoted verbatim
410.110 — General (2017; "410.115 through 410.122") 410.110 General. Luminaires installed in recessed cavities in walls or ceilings, including suspended ceilings, shall comply with 410.115 through 410.122.2017: on-disk NFPA scan §410.110 - quoted verbatim
Delta D18 - 410.110: the compliance range extends "410.115 through 410.122" → "410.115 through 410.126" - 2017: recessed-cavity luminaires "shall comply with 410.115 through 410.122." 2023: "shall comply with 410.115 through 410.126." — the range now spans the renumbered Part XI sections (the 410.120/410.124/410.126 renumbering from 410.118/410.121/410.122). (Machine-verified: "through 410.122" present in 2017, "through 410.126" present in 2023.)
410.115 — Temperature (2023; (B) fire-resistant 150 °C deleted) Luminaires shall be installed so that adjacent combustible material will not be subjected to temperatures in excess of 90°C (194°F). Incandescent luminaires shall have thermal protection and shall be identified as thermally protected. Exception No. 1: Thermal protection shall not be required in a recessed luminaire identified for use and installed in poured concrete. Exception No. 2: Thermal protection shall not be required in a recessed luminaire whose design, construction, and thermal performance characteristics are equivalent to a thermally protected luminaire and are identified as inherently protected.2023: on-disk 2023 rows 410.115(A)-(B) - quoted verbatim
410.115 — Temperature (2017, (A)-(C); (B) is the 150 °C fire-resistant rule) 410.115 Temperature. (A) Combustible Material. Luminaires shall be installed so that adjacent combustible material will not be subjected to temperatures in excess of 90°C (194°F). (B) Fire-Resistant Construction. Where a luminaire is recessed in fire-resistant material in a building of fire-resistant construction, a temperature higher than 90°C (194°F) but not higher than 150°C (302°F) shall be considered acceptable if the luminaire is plainly marked for that service. (C) Recessed Incandescent Luminaires. Incandescent luminaires shall have thermal protection and shall be identified as thermally protected. Exception No. 1: Thermal protection shall not be required in a recessed luminaire identified for use and installed in poured concrete. Exception No. 2: Thermal protection shall not be required in a recessed luminaire whose design, construction, and thermal performance characteristics are equivalent to a thermally protected luminaire and are identified as inherently protected.2017: on-disk NFPA scan §410.115 - quoted verbatim
Delta D19 - 410.115: the 2017 (B) fire-resistant-construction 150 °C provision is deleted (its content moves to 410.116) - 2017 410.115(B): "Where a luminaire is recessed in fire-resistant material in a building of fire-resistant construction, a temperature higher than 90 °C (194 °F) but not higher than 150 °C (302 °F) shall be considered acceptable if the luminaire is plainly marked for that service." In 2023 this 150 °C fire-resistant provision is removed from 410.115 (which now carries only (A) combustible material ≤90 °C and (B) recessed-incandescent thermal protection + its two exceptions). The fire-resistant-recessed treatment is re-homed and expanded in 410.116 (see below). (Machine-verified: "150°C (302°F)" present in 2017 410.115, absent from 2023 410.115.)
410.116 — Clearance and Installation (2023, (A)-(C); adds the NON-FIRE-RATED rule + expanded fire-resistant) A recessed luminaire that is not identified for contact with insulation shall have all recessed parts spaced not less than 13 mm (1/2 in.) from combustible materials. The points of support and the trim finishing off the openings in the ceiling, wall, or other finished surface shall be permitted to be in contact with combustible materials. A recessed luminaire that is identified for contact with insulation, Type IC, shall be permitted to be in contact with combustible materials at recessed parts, points of support, and portions passing through or finishing off the opening in the building structure. Thermal insulation shall not be installed above a recessed luminaire or within 75 mm (3 in.) of the recessed luminaire's enclosure, wiring compartment, ballast, transformer, LED driver, or power supply unless the luminaire is identified as Type IC for insulation contact. Luminaires marked "FOR USE IN NON-FIRE-RATED INSTALLATIONS" shall not be used in fire-rated installations. Where a luminaire is recessed in fire-resistant material in a building of fire-resistant construction, the recessed luminaire shall satisfy one of the following: The recessed luminaire shall be listed for use in a fire resistance—rated construction.The recessed luminaire shall be installed in or used with a luminaire enclosure that is listed for use in a fire resistance-rated construction.The recessed luminaire shall be listed and shall be installed in accordance with a tested fire resistance-rated assembly. When a tested fire resistance-rated assembly allows the installation of a recessed fluorescent luminaire, a recessed LED luminaire of comparable construction shall be permitted.2023: on-disk 2023 rows 410.116(A)(1)-(C) - quoted verbatim
410.116 — Clearance and Installation (2017, (A)-(B); OCR "13 mm (% in.)") 410.116 Clearance and Installation. (A) Clearance. (1) Non-Type IC. A recessed luminaire that is not identified for contact with insulation shall have all recessed parts spaced not less than 13 mm (% in.) from combustible materials. The points of support and the trim finishing off the openings in the ceiling, wall, or other finished surface shall be permitted to be in contact with combustible materials. (2) Type IC. A recessed luminaire that is identified for contact with insulation, Type IC, shall be permitted to be in contact with combustible materials at recessed parts, points of support, and portions passing through or finishing off the opening in the building structure. (B) Installation. Thermal insulation shall not be installed above a recessed luminaire or within 75 mm (3 in.) of the recessed luminaire's enclosure, wiring compartment, ballast, transformer, LED driver, or power supply unless the luminaire is identified as Type IC for insulation contact.2017: on-disk NFPA scan §410.116 - quoted verbatim (disclosed in Sources: "13 mm (% in.)" is a scan misread of "13 mm (1/2 in.)")
Delta D20 - 410.116: adds (C) "FOR USE IN NON-FIRE-RATED INSTALLATIONS" and expands the fire-resistant-recessed rule - 2023 410.116 adds (C): "Luminaires marked "FOR USE IN NON-FIRE-RATED INSTALLATIONS" shall not be used in fire-rated installations," and expands the fire-resistant provision (moved here from the deleted 410.115(B)) into a three-alternative rule: the recessed luminaire shall be listed for fire-resistance-rated construction, OR installed in/with a listed luminaire enclosure, OR listed and installed per a tested fire-resistance-rated assembly (with a comparable-construction LED allowance where the tested assembly allows a recessed fluorescent). (Machine-verified: "FOR USE IN NON-FIRE-RATED INSTALLATIONS" present in 2023 410.116, absent from 2017.)
410.117 — Wiring (2023, (A)-(C)) Conductors that have insulation suitable for the temperature encountered shall be used. Branch-circuit conductors that have an insulation suitable for the temperature encountered shall be permitted to terminate in the luminaire. Tap conductors of a type suitable for the temperature encountered shall be permitted to run from the luminaire terminal connection to an outlet box placed at least 300 mm (1 ft) from the luminaire. Such tap conductors shall be in suitable raceway or Type AC or MC cable of at least 450 mm (18 in.) but not more than 1.8 m (6 ft) in length.2023: on-disk 2023 rows 410.117(A)-(C) - quoted verbatim
410.117 — Wiring (2017, (A)-(C)) 410.117 Wiring. (A) General. Conductors that have insulation suitable for the temperature encountered shall be used. (B) Circuit Conductors. Branch-circuit conductors that have an insulation suitable for the temperature encountered shall be permitted to terminate in the luminaire. (C) Tap Conductors. Tap conductors of a type suitable for the temperature encountered shall be permitted to run from the luminaire terminal connection to an outlet box placed at least 300 mm (1 ft) from the luminaire. Such tap conductors shall be in suitable raceway or Type AC or MC cable of at least 450 mm (18 in.) but not more than 1.8 m (6 ft) in length.2017: on-disk NFPA scan §410.117 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.117 (wiring insulation suitability; branch-circuit termination; 300 mm tap conductors in raceway/AC/MC 450 mm-1.8 m).
Part XI — Construction of Flush and Recessed Luminaires (410.118-410.126; +410.118 NEW; 410.118→120, 410.120→122, 410.121→124, 410.122→126 renumbered)
410.118 — Access to Boxes (NEW in 2023) Luminaires recessed in ceilings, floors, or walls shall not be used to access outlet, pull, or junction boxes or conduit bodies, unless the box or conduit body is an integral part of the listed luminaire.2023: on-disk 2023 row 410.118 - quoted verbatim (NO 2017 counterpart at 410.118)
Delta D21 - 410.118: NEW in 2023 — recessed luminaires shall not be used to access boxes/conduit bodies - Entirely new in 2023: "Luminaires recessed in ceilings, floors, or walls shall not be used to access outlet, pull, or junction boxes or conduit bodies, unless the box or conduit body is an integral part of the listed luminaire." (The 2017 410.118 was the "Temperature" rule, which is renumbered to 2023 410.120.) (Machine-verified: "410.118" 2023 text is the box-access rule; 2017 410.118 is "Temperature... 90°C".)
410.120 — Temperature (2023; was 2017 410.118) Luminaires shall be constructed such that adjacent combustible material is not subject to temperatures in excess of 90°C (194°F).2023: on-disk 2023 row 410.120 - quoted verbatim (renumbered from 2017 410.118; word-identical)
410.118 — Temperature (2017; → 2023 410.120) 410.118 Temperature. Luminaires shall be constructed such that adjacent combustible material is not subject to temperatures in excess of 90°C (194°F).2017: on-disk NFPA scan §410.118 - quoted verbatim
410.122 — Lamp Wattage Marking (2023; was 2017 410.120) Incandescent lamp luminaires shall be marked to indicate the maximum allowable wattage of lamps. The markings shall be permanently installed, in letters at least 6 mm (1/4 in.) high, and shall be located where visible during relamping.2023: on-disk 2023 row 410.122 - quoted verbatim (renumbered from 2017 410.120; word-identical; OCR "6 mm (% in.)"→"6 mm (1/4 in.)")
410.120 — Lamp Wattage Marking (2017; → 2023 410.122; OCR "6 mm (% in.)") 410.120 Lamp Wattage Marking. Incandescent lamp luminaires shall be marked to indicate the maximum allowable wattage of lamps. The markings shall be permanently installed, in letters at least 6 mm (% in.) high, and shall be located where visible during relamping.2017: on-disk NFPA scan §410.120 - quoted verbatim
410.124 — Solder Prohibited (2023; was 2017 410.121) No solder shall be used in the construction of a luminaire recessed housing.2023: on-disk 2023 row 410.124 - quoted verbatim (renumbered from 2017 410.121; word-identical)
410.121 — Solder Prohibited (2017; → 2023 410.124) 410.121 Solder Prohibited. No solder shall be used in the construction of a luminaire recessed housing.2017: on-disk NFPA scan §410.121 - quoted verbatim
410.126 — Lampholders (2023; was 2017 410.122) Lampholders of the screw shell type shall be of porcelain or other suitable insulating materials.2023: on-disk 2023 row 410.126 - quoted verbatim (renumbered from 2017 410.122; word-identical)
410.122 — Lampholders (2017; → 2023 410.126) 410.122 Lampholders. Lampholders of the screw shell type shall be of porcelain or other suitable insulating materials.2017: on-disk NFPA scan §410.122 - quoted verbatim
Renumbered, word-identical 2017→2023 (machine-verified): 410.118→410.120 (recessed-luminaire 90 °C construction), 410.120→410.122 (incandescent max-wattage marking, 6 mm / 1/4 in.), 410.121→410.124 (no solder in a luminaire recessed housing), and 410.122→410.126 (screw-shell lampholders of porcelain/suitable insulating material). The 2017 OCR fraction artifacts ("% in.") resolve in 2023.
Part XII — Special Provisions for Electric-Discharge Lighting (410.130-410.139; 410.130 restructured, (G)→410.71)
410.130 — General (2023, (A)-(F); (G) Disconnecting Means moved to 410.71) Equipment for use with electric-discharge lighting systems and designed for an open-circuit voltage of 1000 volts or less shall be of a type identified for such service. The terminals of an electric-discharge lamp shall be considered as energized where any lamp terminal is connected to a circuit of over 300 volts. Transformers of the oil-filled type shall not be used. In addition to complying with the general requirements for luminaires, such equipment shall comply with Part XII of this article. The ballast of a fluorescent luminaire installed indoors shall have integral thermal protection. Replacement ballasts shall also have thermal protection integral with the ballast. A simple reactance ballast in a fluorescent luminaire with straight tubular lamps shall not be required to be thermally protected. A ballast in a fluorescent exit luminaire shall not have thermal protection. A ballast in a fluorescent luminaire that is used for egress lighting and energized only during a failure of the normal supply shall not have thermal protection. Recessed high-intensity luminaires designed to be installed in wall or ceiling cavities shall have thermal protection and be identified as thermally protected. Thermal protection shall not be required in a recessed high-intensity luminaire whose design, construction, and thermal performance characteristics are equivalent to a thermally protected luminaire and are identified as inherently protected. Thermal protection shall not be required in a recessed high-intensity discharge luminaire identified for use and installed in poured concrete. A recessed remote ballast for a high-intensity discharge luminaire shall have thermal protection that is integral with the ballast and shall be identified as thermally protected. Luminaires that use a metal halide lamp other than a thick-glass parabolic reflector lamp (PAR) shall be provided with a containment barrier that encloses the lamp, or shall be provided with a physical means that only allows the use of a lamp that is Type O. Informational Note: See ANSI C78.389, American National Standard for Electric Lamps -High Intensity Discharge, Methods of Measuring Characteristics.2023: on-disk 2023 rows 410.130(A)-(F) - quoted verbatim
410.130 — General (2017, (A)-(G); (G) is the Disconnecting Means rule; OCR "shail") 410.130 General. (A) Open-Circuit Voltage of 1000 Volts or Less. Equipment for use with electric-discharge lighting systems and designed for an open-circuit voltage of 1000 volts or less shall be of a type identified for such service. (B) Considered as Energized. The terminals of an electricdischarge lamp shall be considered as energized where any lamp terminal is connected to a circuit of over 300 volts. (C) Transformers of the Oil-Filled Type. Transformers of the oil-filled type shall not be used. (D) Additional Requirements. In addition to complying with the general requirements for luminaires, such equipment shall comply with Part XII of this article. (E) Thermal Protection — Fluorescent Luminaires. (1) Integral Thermal Protection. The ballast of a fluorescent luminaire installed indoors shall have integral thermal protection. Replacement ballasts shall also have thermal protection integral with the ballast. (2) Simple Reactance Ballasts. A simple reactance ballast in a fluorescent luminaire with straight tubular lamps shall not be required to be thermally protected. (3) Exit Luminaires. A ballast in a fluorescent exit luminaire shail not have thermal protection. (4) Egress Luminaires. A ballast in a fluorescent luminaire that is used for egress lighting and energized only during a failure of the normal supply shall not have thermal protection. (F) High-Intensity Discharge Luminaires. (1) Recessed. Recessed high-intensity luminaires designed to be installed in wall or ceiling cavities shall have thermal protection and be identified as thermally protected. (2) Inherently Protected. Thermal protection shall not be required in a recessed high-intensity luminaire whose design, construction, and thermal performance characteristics are equivalent to a thermally protected luminaire and are identified as inherently protected. (3) Installed in Poured Concrete. Thermal protection shall not be required in a recessed high-intensity discharge luminaire identified for use and installed in poured concrete. (4) Recessed Remote Ballasts. A recessed remote ballast for a high-intensity discharge luminaire shall have thermal protection that is integral with the ballast and shall be identified as thermally protected. (5) Metal Halide Lamp Containment. Luminaires that use a metal halide lamp other than a thick-glass parabolic reflector lamp (PAR) shall be provided with a containment barrier that encloses the lamp, or shall be provided with a physical means that only allows the use of a lamp that is Type O. Informational Note: See ANSI Standard C78.389, American National Standard for Electric Lamps — High Intensity Discharge, Methods of Measuring Characteristics. (G) Disconnecting Means. (1) General. In indoor locations other than dwellings and associated accessory structures, fluorescent luminaires that utilize double-ended lamps and contain ballast(s) that can be serviced in place shall have a disconnecting means either internal or external to each luminaire. For existing installed luminaires without disconnecting means, at the time a ballast is replaced, a disconnecting means shall be installed. The line side terminals of the disconnecting means shall be guarded. Exception No. 1: A disconnecting means shall not be required for luminaires installed in hazardous (classified) location(s). Exception No. 2: A disconnecting means shall not be required for luminaires that provide emergency illumination required in 700.16. Exception No. 3: For cord-and-plug-connected luminaires, an accessible separable connector or an accessible plug and receptacle shall be permitted to serve as the disconnecting means. Exception No. 4: Where more than one luminaire is installed and supplied by other than a multiwire branch circuit, a disconnecting means shall not be required for every luminaire when the design of the installation includes disconnecting means, such that the illuminated space cannot be left in total darkness. (2) Multiwire Branch Circuits. When connected to multiwire branch circuits, the disconnecting means shall simultaneously break all the supply conductors to the ballast, including the grounded conductor. (3) Location, The disconnecting means shall be located so as to be accessible to qualified persons before servicing or maintaining the ballast. Where the disconnecting means is external to the luminaire, it shall be a single device, and shall be attached to the luminaire or the luminaire shall be located within sight of the disconnecting means.2017: on-disk NFPA scan §410.130 - quoted verbatim (disclosed in Sources: "a fluorescent exit luminaire shail not have thermal protection" — a scan misread of "shall")
Delta D22 - 410.130: restructured — the (G) Disconnecting Means rule is relocated to new 410.71; (E)/(F) re-flowed - 2017 410.130 carries (A) ≤1000 V identified equipment, (B) energized terminals >300 V, (C) no oil-filled transformers, (D) comply with Part XII, (E) fluorescent thermal protection (1)-(4), (F) high-intensity discharge (1)-(5), and (G) Disconnecting Means (General / Multiwire / Location). In 2023, the (A)-(F) content is retained (re-flowed without the sub-letter headers), the (G) Disconnecting Means content is relocated to the new 410.71 (and extended to LED luminaires, see D15), and the metal-halide containment (old (F)(5)) is retained within the restructured 410.130. (Machine-verified: "(G) Disconnecting Means" present in 2017 410.130, absent from 2023 410.130; the disconnecting-means text present in 2023 410.71.)
410.134 — Direct-Current Equipment (2023; OCR "de"→"dc") Luminaires installed on dc circuits shall be equipped with auxiliary equipment and resistors designed for dc operation. The luminaires shall be marked for dc operation.2023: on-disk 2023 row 410.134 - quoted verbatim
410.134 — Direct-Current Equipment (2017; OCR "de circuits") 410.134 Direct-Current Equipment. Luminaires installed on de circuits shall be equipped with auxiliary equipment and resistors designed for de operation. The luminaires shall be marked for dc operation.2017: on-disk NFPA scan §410.134 - quoted verbatim (disclosed in Sources: "de circuits"/"de operation" — a scan misread of "dc")
410.135 — Open-Circuit Voltage Exceeding 300 Volts (2023) Equipment having an open-circuit voltage exceeding 300 volts shall not be installed in dwelling occupancies unless such equipment is designed so that there will be no exposed live parts when lamps are being inserted, are in place, or are being removed.2023: on-disk 2023 row 410.135 - quoted verbatim
410.135 — Open-Circuit Voltage Exceeding 300 Volts (2017) 410.135 Open-Circuit Voltage Exceeding 300 Volts. Equipment having an open-circuit voltage exceeding 300 volts shall not be installed in dwelling occupancies unless such equipment is designed so that there will be no exposed live parts when lamps are being inserted, are in place, or are being removed.2017: on-disk NFPA scan §410.135 - quoted verbatim
410.136 — Luminaire Mounting (2023, (A)-(B); test-standard refs updated) Luminaires that have exposed ballasts, transformers, LED drivers, or power supplies shall be installed such that ballasts, transformers, LED drivers, or power supplies shall not be in contact with combustible material unless listed for such condition. Where a surface-mounted luminaire containing a ballast, transformer, LED driver, or power supply is to be installed on combustible low-density cellulose fiberboard, it shall be marked for this condition or shall be spaced not less than 38 mm (11/2 in.) from the surface of the fiberboard. Where such luminaires are partially or wholly recessed, 410.110 through 410.126 shall apply. Informational Note: See ASTM E84-20, Standard Test Method for Surface Burning Characteristics of Building Materials, or ANSI/UL 723-2018, Standard for Test for Surface Burning Characteristics of Building Materials. Combustible low-density cellulose fiberboard includes sheets, panels, and tiles that have a density of 320 kg/m3 (20 lb/ft3) or less and that are formed of bonded plant fiber material but does not include solid or laminated wood or fiberboard that has a density in excess of 320 kg/m3 (20 lb/ft3) or is a material that has been integrally treated with fire-retarding chemicals to the degree that the flame spread index in any plane of the material will not exceed 25, determined in accordance with tests for surface burning characteristics of building materials.2023: on-disk 2023 rows 410.136(A)-(B) - quoted verbatim
410.136 — Luminaire Mounting (2017, (A)-(B); older ASTM/UL revs) 410.136 Luminaire Mounting. (A) Exposed Components. Luminaires that have exposed ballasts, transformers, LED drivers, or power supplies shall be installed such that ballasts, transformers, LED drivers, or power supplies shall not be in contact with combustible material unless listed for such condition. (B) Combustible Low-Density Cellulose Fiberboard. Where a surface-mounted luminaire containing a ballast, transformer, LED driver, or power supply is to be installed on combustible low-density cellulose fiberboard, it shall be marked for this condition or shall be spaced not less than 38 mm (1% in.) from the surface of the fiberboard. Where such luminaires are partially or wholly recessed, the provisions of 410.110 through 410.122 shall apply. Informational Note: Combustible low-density cellulose fiberboard includes sheets, panels, and tiles that have a density of 320 kg/m? (20 Ib/ft*) or less and that are formed of bonded plant fiber material but does not include solid or laminated wood or fiberboard that has a density in excess of 320 kg/ m? (20 Ib/ft?) or is a material that has been integrally treated with fire-retarding chemicals to the degree that the flame spread index in any plane of the material will not exceed 25, determined in accordance with tests for surface burning characteristics of building materials. See ANSI/ASTM E84-2015a, Standard Test Method for Surface Burning Characteristics of Building Materials or ANSI/UL 723-2013, Standard for Test for Surface Burning Characteristics of Building Materials.2017: on-disk NFPA scan §410.136 - quoted verbatim (2017 cites ANSI/ASTM E84-2015a and ANSI/UL 723-2013)
Delta D23 - 410.136: test-standard references updated and the recessed cross-range extends to 410.126 - 2023 410.136 updates the surface-burning test references from "ANSI/ASTM E84-2015a" and "ANSI/UL 723-2013" to "ASTM E84-20" and "ANSI/UL 723-2018," and changes the partially/wholly-recessed cross-reference from "the provisions of 410.110 through 410.122 shall apply" to "410.110 through 410.126 shall apply" (the Part XI renumbering). The 38 mm (1½ in.) cellulose-fiberboard spacing and the 320 kg/m³ (20 lb/ft³) density definition are unchanged. (Machine-verified: "UL 723-2018" present in 2023, "UL 723-2013" present in 2017.)
410.137 — Equipment Not Integral with Luminaire (2023, (A)-(C); adds LED driver) Auxiliary equipment, including reactors, capacitors, resistors, and similar equipment, where not installed as part of a luminaire assembly, shall be enclosed in accessible, permanently installed metal cabinets. Separately mounted ballasts, transformers, LED drivers, or power supplies that are listed for direct connection to a wiring system shall not be required to be additionally enclosed. Wired luminaire sections are paired, with a ballast(s) or LED driver(s) supplying a light source or light sources in both. For interconnection between paired units, it shall be permissible to use metric designator 12 (trade size 3/8) flexible metal conduit in lengths not exceeding 7.5 m (25 ft), installed in accordance with Part II of Article 348. Luminaire wire operating at line voltage, supplying only the ballast(s) or LED driver(s) of one of the paired luminaires, shall be permitted in the same raceway as the light source supply wires of the paired luminaires where the voltage rating of the light source supply wires is greater than the line voltage.2023: on-disk 2023 rows 410.137(A)-(C) - quoted verbatim
410.137 — Equipment Not Integral with Luminaire (2017, (A)-(C)) 410.137 Equipment Not Integral with Luminaire. (A) Metal Cabinets. Auxiliary equipment, including reactors, capacitors, resistors, and similar equipment, where not installed as part of a luminaire assembly, shall be enclosed in accessible, permanently installed metal cabinets. (B) Separate Mounting. Separately mounted ballasts, transformers, LED drivers, or power supplies that are listed for direct connection to a wiring system shall not be required to be additionally enclosed. (C) Wired Luminaire Sections. Wired luminaire sections are paired, with a ballast(s) supplying a lamp or lamps in both. For interconnection between paired units, it shall be permissible to use metric designator 12 (trade size %) flexible metal conduit in lengths not exceeding 7.5 m (25 ft), in conformance with Article 348. Luminaire wire operating at line voltage, supplying only the ballast(s) of one of the paired luminaires shall be permitted in the same raceway as the lamp supply wires of the paired luminaires.2017: on-disk NFPA scan §410.137 - quoted verbatim
Delta D24 - 410.137(C): adds "LED driver(s)" and the 348 raceway cite becomes "Part II of Article 348" + a voltage-rating condition - 2023 410.137(C) (Wired Luminaire Sections) changes "with a ballast(s) supplying a lamp or lamps in both" to "with a ballast(s) or LED driver(s) supplying a light source or light sources in both," changes "in conformance with Article 348" to "installed in accordance with Part II of Article 348," and adds the condition that the luminaire wire in the shared raceway is permitted "where the voltage rating of the light source supply wires is greater than the line voltage." (Machine-verified: "LED driver(s)" present in 2023 410.137, absent from 2017; "Part II of Article 348" present in 2023.)
410.138 — Autotransformers (2023) An autotransformer that is used to raise the voltage to more than 300 volts, as part of a ballast for supplying lighting units, shall be supplied only by a grounded system.2023: on-disk 2023 row 410.138 - quoted verbatim
410.138 — Autotransformers (2017) 410.138 Autotransformers. An autotransformer that is used to raise the voltage to more than 300 volts, as part of a ballast for supplying lighting units, shall be supplied only by a grounded system.2017: on-disk NFPA scan §410.138 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.134 (dc auxiliary equipment/resistors, marked for dc), 410.135 (>300 V open-circuit not in dwellings unless no exposed live parts), 410.138 (autotransformer >300 V grounded-system only), and 410.139 (snap switches comply with 404.14).
Part XIII — Special Provisions for Electric-Discharge Lighting Over 1000 Volts (410.140-410.146)
410.140 — General (2023, (A)-(D)) Electric-discharge lighting systems with an open-circuit voltage exceeding 1000 volts shall be listed and installed in conformance with that listing. Equipment that has an open-circuit voltage exceeding 1000 volts shall not be installed in or on dwelling occupancies. The terminal of an electric-discharge lamp shall be considered as a live part. In addition to complying with the general requirements for luminaires, such equipment shall comply with Part XIII of this article.2023: on-disk 2023 rows 410.140(A)-(D) - quoted verbatim
410.140 — General (2017, (A)-(D)) 410.140 General. (A) Listing. Electric-discharge lighting systems with an opencircuit voltage exceeding 1000 volts shall be listed and installed in conformance with that listing. (B) Dwelling Occupancies. Equipment that has an opencircuit voltage exceeding 1000 volts shall not be installed in or on dwelling occupancies. (C) Live Parts. The terminal of an electric-discharge lamp shall be considered as a live part. (D) Additional Requirements. In addition to complying with the general requirements for luminaires, such equipment shall comply with Part XIII of this article. Informational Note: For signs and outline lighting, see Article 600.2017: on-disk NFPA scan §410.140 - quoted verbatim
Delta D32 - 410.140: the 2017 "For signs and outline lighting, see Article 600" Informational Note is dropped - 2017 410.140 ends with "Informational Note: For signs and outline lighting, see Article 600." In 2023 that informational note is deleted — 410.140 ends after the Part XIII compliance sentence. The four substantive provisions (listed; not in dwellings; lamp terminal = live part; comply with Part XIII) are otherwise unchanged. (Machine-verified: "see Article 600" present in 2017 410.140, absent from 2023.)
410.141 — Control (2023, (A)-(B); "lockable open") Luminaires or lamp installation shall be controlled either singly or in groups by an externally operable switch or circuit breaker that opens all ungrounded primary conductors. The switch or circuit breaker shall be located within sight from the luminaires or lamps, or it shall be permitted to be located elsewhere if it is lockable open in accordance with 110.25.2023: on-disk 2023 rows 410.141(A)-(B) - quoted verbatim
410.141 — Control (2017, (A)-(B); "lockable") 410.141 Control. (A) Disconnection. Luminaires or lamp installation shall be controlled either singly or in groups by an externally operable switch or circuit breaker that opens all ungrounded primary conductors. (B) Within Sight or Locked Type. The switch or circuit breaker shall be located within sight from the luminaires or lamps, or it shall be permitted to be located elsewhere if it is lockable in accordance with 110.25.2017: on-disk NFPA scan §410.141 - quoted verbatim
Delta D25 - 410.141(B): "lockable" → "lockable open" per 110.25 - 2017 (B): the switch or circuit breaker "shall be permitted to be located elsewhere if it is lockable in accordance with 110.25." 2023 (B): "...if it is lockable open in accordance with 110.25." — 2023 specifies the lockable state (open), matching 110.25's lockable-open disconnecting language. (Machine-verified: "lockable open" present in 2023, "lockable in accordance" (without "open") present in 2017.)
410.142 — Lamp Terminals and Lampholders (2023) Parts that must be removed for lamp replacement shall be hinged or held captive. Lamps or lampholders shall be designed so that there are no exposed live parts when lamps are being inserted or removed.2023: on-disk 2023 row 410.142 - quoted verbatim
410.142 — Lamp Terminals and Lampholders (2017) 410.142 Lamp Terminals and Lampholders. Parts that must be removed for lamp replacement shall be hinged or held captive. Lamps or lampholders shall be designed so that there are no exposed live parts when lamps are being inserted or removed.2017: on-disk NFPA scan §410.142 - quoted verbatim
410.143 — Transformers (2023, (A)-(D)) Transformers shall be enclosed, identified for the use, and listed. The secondary circuit voltage shall not exceed 15,000 volts, nominal, under any load condition. The voltage to ground of any output terminals of the secondary circuit shall not exceed 7500 volts under any load conditions. Transformers shall have a secondary short-circuit current rating of not more than 150 mA if the open-circuit voltage is over 7500 volts, and not more than 300 mA if the open-circuit voltage rating is 7500 volts or less. Secondary circuit outputs shall not be connected in parallel or in series.2023: on-disk 2023 rows 410.143(A)-(D) - quoted verbatim
410.143 — Transformers (2017, (A)-(D)) 410.143 Transformers. (A) Type. Transformers shall be enclosed, identified for the use, and listed. (B) Voltage. The secondary circuit voltage shall not exceed 15,000 volts, nominal, under any load condition. The voltage to ground of any output terminals of the secondary circuit shall not exceed 7500 volts under any load conditions. (C) Rating. Transformers shall have a secondary short-circuit current rating of not more than 150 mA if the open-circuit voltage is over 7500 volts, and not more than 300 mA if the opencircuit voltage rating is 7500 volts or less. (D) Secondary Connections. Secondary circuit outputs shall not be connected in parallel or in series.2017: on-disk NFPA scan §410.143 - quoted verbatim
410.144 — Transformer Locations (2023, (A)-(C)) Transformers shall be accessible after installation. Transformers shall be installed as near to the lamps as practicable to keep the secondary conductors as short as possible. Transformers shall be located so that adjacent combustible materials are not subjected to temperatures in excess of 90°C (194°F).2023: on-disk 2023 rows 410.144(A)-(C) - quoted verbatim
410.144 — Transformer Locations (2017, (A)-(C)) 410.144 Transformer Locations. (A) Accessible. Transformers shall be accessible after installation. (B) Secondary Conductors. Transformers shall be installed as near to the lamps as practicable to keep the secondary conductors as short as possible. (C) Adjacent to Combustible Materials. Transformers shall be located so that adjacent combustible materials are not subjected to temperatures in excess of 90°C (194°F).2017: on-disk NFPA scan §410.144 - quoted verbatim
410.145 — Exposure to Damage (2023) Lamps shall not be located where normally exposed to physical damage.2023: on-disk 2023 row 410.145 - quoted verbatim
410.145 — Exposure to Damage (2017) 410.145 Exposure to Damage. Lamps shall not be located where normally exposed to physical damage.2017: on-disk NFPA scan §410.145 - quoted verbatim
410.146 — Marking (2023; "Caution _____ volts") Each luminaire or each secondary circuit of tubing having an open-circuit voltage of over 1000 volts shall have a clearly legible marking in letters not less than 6 mm (1/4 in.) high reading "Caution _____ volts." The voltage indicated shall be the rated open-circuit voltage. The caution sign(s) or label(s) shall comply with 110.21 (B).2023: on-disk 2023 row 410.146 - quoted verbatim
410.146 — Marking (2017; OCR "% in.") 410.146 Marking. Each luminaire or each secondary circuit of tubing having an open-circuit voltage of over 1000 volts shall have a clearly legible marking in letters not less than 6 mm (% in.) high reading “Caution ___ volts.” The voltage indicated shall be the rated open-circuit voltage. The caution sign(s) or label(s) shall comply with 110.21(B).2017: on-disk NFPA scan §410.146 - quoted verbatim (disclosed in Sources: "6 mm (% in.)" — a scan misread of "6 mm (1/4 in.)")
Unchanged 2017→2023 (machine-verified, modulo sub-header reflow): 410.142 (hinged/captive parts; no exposed live parts on relamping), 410.143 (transformers enclosed/listed; 15,000 V / 7,500 V-to-ground limits; 150/300 mA short-circuit), 410.144 (accessible, near lamps, 90 °C), 410.145 (not where normally exposed to damage), and 410.146 ("Caution ___ volts" marking per 110.21(B)). 410.140 is not in this set — its 2017 "see Article 600" note is deleted in 2023 (D32).
Part XIV — Lighting Track (410.150-410.155; 410.151→410.150 renumbered)
410.150 — Installation (2023, (A)-(D); was 2017 410.151; 220.43→220.46) Lighting track shall be permanently installed and permanently connected to a branch circuit. Only lighting track fittings shall be installed on lighting track. Lighting track fittings shall not be equipped with general-purpose receptacles. The connected load on lighting track shall not exceed the rating of the track. Lighting track shall be supplied by a branch circuit having a rating not more than that of the track. The load calculation in 220.46(B) shall not be required to limit the length of track on a single branch circuit, and it shall not be required to limit the number of luminaires on a single track. Lighting track shall not be installed in the following locations: Where likely to be subjected to physical damageIn wet or damp locationsWhere subject to corrosive vaporsIn storage battery roomsIn hazardous (classified) locationsWhere concealedWhere extended through walls or partitionsLess than 1.5 m (5 ft) above the finished floor except where protected from physical damage or track operating at less than 30 volts rms open-circuit voltageWhere prohibited by 410.10(D) Fittings identified for use on lighting (rack shall be designed specifically for the track on which they are to be installed. They shall be securely fastened to the track, shall maintain polarization and connections to the equipment grounding conductor, and shall be designed to be suspended directly from the track.2023: on-disk 2023 rows 410.150(A)-(D) - quoted verbatim (renumbered from 2017 410.151)
410.151 — Installation (2017, (A)-(D); → 2023 410.150; cites 220.43(B)) 410.151 Installation. (A) Lighting Track. Lighting track shall be permanently installed and permanently connected to a branch circuit. Only lighting track fittings shall be installed on lighting track. Lighting track fittings shall not be equipped with general-purpose receptacles. (B) Connected Load. The connected load on lighting track shall not exceed the rating of the track. Lighting track shall be supplied by a branch circuit having a rating not more than that of the track. The load calculation in 220.43(B) shall not be required to limit the length of track on a single branch circuit, and it shall not be required to limit the number of luminaires on a single track. (C) Locations Not Permitted. Lighting track shall not be installed in the following locations: (1) Where likely to be subjected to physical damage (2) In wet or damp locations (3) Where subject to corrosive vapors (4) In storage battery rooms (5) In hazardous (classified) locations (6) Where concealed (7) Where extended through walls or partitions (8) Less than 1.5 m (5 ft) above the finished floor except where protected from physical damage or track operating at less than 30 volts rms open-circuit voltage (9) Where prohibited by 410.10(D) (D) Support. Fittings identified for use on lighting track shall be designed specifically for the track on which they are to be installed. They shall be securely fastened to the track, shall maintain polarization and connections to the equipment grounding conductor, and shall be designed to be suspended directly from the track.2017: on-disk NFPA scan §410.151 - quoted verbatim
Delta D26 - 410.151 → 410.150: renumbered, and the load-calculation cite moves 220.43(B) → 220.46(B) - 2017 410.151 (Lighting Track Installation) is renumbered 410.150 in 2023. Within it, the connected-load sentence changes the load-calculation reference from "The load calculation in 220.43(B) shall not be required to limit the length of track..." to "The load calculation in 220.46(B) shall not be required to limit the length of track..." (the 2023 Article 220 renumber of the branch-circuit lighting-load subsection). The 410.10(D) cross-reference in the not-permitted-locations list is unchanged. (The 2023 dataset also prints a "lighting (rack" typo in (D) — a dataset artifact for "lighting track.") (Machine-verified: "220.43(B)" present in 2017, "220.46(B)" present in 2023.)
410.153 — Heavy-Duty Lighting Track (2023) Heavy-duty lighting track is lighting track identified for use exceeding 20 amperes. Each fitting attached to a heavy-duty lighting track shall have individual overcurrent protection.2023: on-disk 2023 row 410.153 - quoted verbatim
410.153 — Heavy-Duty Lighting Track (2017) 410.153 Heavy-Duty Lighting Track. Heavy-duty lighting track is lighting track identified for use exceeding 20 amperes. Each fitting attached to a heavy-duty lighting track shall have individual overcurrent protection.2017: on-disk NFPA scan §410.153 - quoted verbatim
410.154 — Fastening (2023) Lighting track shall be securely mounted so that each fastening is suitable for supporting the maximum weight of luminaires that can be installed. Unless identified for supports at greater intervals, a single section 1.2 m (4 ft) or shorter in length shall have two supports, and, where installed in a continuous row, each individual section of not more than 1.2 m (4 ft) in length shall have one additional support.2023: on-disk 2023 row 410.154 - quoted verbatim
410.154 — Fastening (2017) 410.154 Fastening. Lighting track shall be securely mounted so that each fastening is suitable for supporting the maximum weight of luminaires that can be installed. Unless identified for supports at greater intervals, a single section 1.2 m (4 ft) or shorter in length shall have two supports, and, where installed in a continuous row, each individual section of not more than 1.2 m (4 ft) in length shall have one additional support.2017: on-disk NFPA scan §410.154 - quoted verbatim
410.155 — Construction Requirements (2023, (A)-(B); EGC rewording) The housing for the lighting track system shall be of substantial construction to maintain rigidity. The conductors shall be installed within the track housing, permitting insertion of a luminaire, and designed to prevent tampering and accidental contact with live parts. Components of lighting track systems of different voltages shall not be interchangeable. The track conductors shall be a minimum 12 AWG or equal and shall be copper. The track system ends shall be insulated and capped. Lighting track shall be connected to the equipment grounding conductor in accordance with Part V of this article, and the track sections shall be securely coupled to maintain continuity of the circuitry, polarization, and grounding throughout.2023: on-disk 2023 rows 410.155(A)-(B) - quoted verbatim
410.155 — Construction Requirements (2017, (A)-(B); "grounded per Article 250") 410.155 Construction Requirements. (A) Construction. The housing for the lighting track system shall be of substantial construction to maintain rigidity. The conductors shall be installed within the track housing, permitting insertion of a luminaire, and designed to prevent tampering and accidental contact with live parts. Components of lighting track systems of different voltages shall not be interchangeable. The track conductors shall be a minimum 12 AWG or equal and shall be copper. The track system ends shall be insulated and capped. (B) Grounding. Lighting track shall be grounded in accordance with Article 250, and the track sections shall be securely coupled to maintain continuity of the circuitry, polarization, and grounding throughout.2017: on-disk NFPA scan §410.155 - quoted verbatim
Delta D27 - 410.155(B): "grounded in accordance with Article 250" → "connected to the EGC in accordance with Part V" - 2017 (B): "Lighting track shall be grounded in accordance with Article 250, and the track sections shall be securely coupled..." 2023 (B): "Lighting track shall be connected to the equipment grounding conductor in accordance with Part V of this article, and the track sections shall be securely coupled..." — same pattern as 410.40 (D7): drops the Article 250 cite, names the EGC, points to Part V. (Machine-verified: "grounded in accordance with Article 250" present in 2017 410.155, absent from 2023.)
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.153 (heavy-duty track >20 A; individual OCPD per fitting) and 410.154 (secure mounting; two supports for ≤1.2 m / 4 ft sections; one additional in a continuous row).
Part XV — Decorative Lighting and Similar Accessories (410.160)
410.160 — Listing of Decorative Lighting (2023) Decorative lighting and similar accessories used for holiday lighting and similar purposes, in accordance with 590.3(B), shall be listed.2023: on-disk 2023 row 410.160 - quoted verbatim
410.160 — Listing of Decorative Lighting (2017; OCR title "Listing of Decorative Lighting,") 410.160 Listing of Decorative Lighting, Decorative lighting and similar accessories used for holiday lighting and similar purposes, in accordance with 590.3(B), shall be listed.2017: on-disk NFPA scan §410.160 - quoted verbatim
Unchanged 2017→2023 (substantively identical — the 2023 dataset drops the (A)/(B) sub-headers and resolves 2017 scan OCR, so not byte-identical; the 27 strict word-identical sections are machine-verified in the verify script): 410.160 — decorative lighting and similar accessories for holiday lighting per 590.3(B) shall be listed.
Part XVI — Horticultural Lighting (410.170-410.186) — NEW in 2023
Delta D28 - NEW Part XVI (410.170-410.186): horticultural lighting — zero of these tokens in the on-disk 2017 scan - 2023 adds an entire Part XVI for lighting equipment identified for horticultural use. 410.170 permits Parts I-XII luminaires for horticultural lighting (with an informational note on the spectral characteristic for plant growth); 410.172 requires listing; 410.174 install/use per the listing; 410.176 not for general illumination and not where subject to physical damage or concealed; 410.178 flexible cord only as part of listed horticultural equipment (three listed uses, remote power sources incl. LED drivers/ballasts); 410.180 fittings/connectors as part of the listed device; 410.182 EGC per Part V; 410.184 the headline GFCI/SPGFCI rule; and 410.186 support fittings per instructions, securely fastened. (Machine-verified: "410.170" through "410.186" have no on-disk 2017 sections; the on-disk 2017 Article 410 region has zero horticultural tokens.)
410.170 — General (NEW; Parts I-XII luminaires for horticultural) Luminaires complying with Parts, I, II, III, IV, V, VI, VII, IX, X, XI, and XII of this article shall be permitted to be used for horticultural lighting. Part XVI shall additionally apply to lighting equipment specifically identified for horticultural use. Informational Note: Lighting equipment identified for horticultural use is designed to provide a spectral characteristic needed for the growth of plants and can also provide supplemental general illumination within the growing environment.2023: on-disk 2023 row 410.170 - quoted verbatim
410.172 — Listing (NEW) Lighting equipment identified for horticultural use shall be listed.2023: on-disk 2023 row 410.172 - quoted verbatim
410.174 — Installation and Use (NEW) Lighting equipment identified for horticultural use shall be installed and used in accordance with the manufacturer's installation instructions and installation markings on the equipment as required by that listing.2023: on-disk 2023 row 410.174 - quoted verbatim
410.176 — Uses Not Permitted (NEW, (A)-(B)) Lighting equipment identified for horticultural use shall not be installed as lighting for general illumination unless such use is indicated in the manufacturer's instructions. Lighting equipment identified for horticultural use shall not be installed where it is likely to be subject to physical damage or where concealed.2023: on-disk 2023 rows 410.176(A)-(B) - quoted verbatim
410.178 — Flexible Cord (NEW) Flexible cord shall only be permitted when provided as part of listed lighting equipment identified for horticultural use for any of the following uses: Connecting a horticultural lighting luminaire directly to a branch circuit outletInterconnecting horticultural lighting luminairesConnecting a horticultural lighting luminaire to a remote power sourceInformational Note: Remote power sources include LED drivers, fluorescent ballasts, or HID ballasts.2023: on-disk 2023 row 410.178 - quoted verbatim
410.180 — Fittings and Connectors (NEW) Fittings and connectors attached to flexible cords shall be provided as part of a listed horticultural lighting equipment device or system and installed in accordance with the instructions provided as part of that listing.2023: on-disk 2023 row 410.180 - quoted verbatim
410.182 — Equipment Grounding (NEW) Lighting equipment identified for horticultural use shall be connected to the equipment grounding conductor in accordance with Part V of this article.2023: on-disk 2023 row 410.182 - quoted verbatim
410.184 — GFCI / SPGFCI Protection (NEW; the headline) Lighting equipment identified for horticultural use and employing flexible cord(s) with one or more separable connector(s) or attachment plug(s) shall be supplied by lighting outlets protected by a listed GFCI. Exception: Circuits exceeding 150 volts to ground shall be protected by a listed SPGFCI. Informational Note: See UL 943C, Outline of Investigation for Special Purpose Ground-Fault Circuit-Interrupters, for information on special purpose ground-fault circuit interrupters.2023: on-disk 2023 row 410.184 - quoted verbatim
Delta D29 - 410.184 (NEW): cord-connected horticultural lighting requires listed GFCI — or listed SPGFCI over 150 V to ground (UL 943C) - The 410.184 rule: "Lighting equipment identified for horticultural use and employing flexible cord(s) with one or more separable connector(s) or attachment plug(s) shall be supplied by lighting outlets protected by a listed GFCI. Exception: Circuits exceeding 150 volts to ground shall be protected by a listed SPGFCI." Informational Note cites UL 943C (Special Purpose Ground-Fault Circuit-Interrupters). (Mike Holt 2023 documents this entry — it appears in the on-disk MH file under the Article 450 region, misplaced, but is an in-scope Article 410 change: the title/text were revised to clarify GFCI is required when horticultural lighting is cord-connected, with the new SPGFCI exception for >150 V to ground.) (Machine-verified: "410.184" has no on-disk 2017 section; "UL 943C" and "SPGFCI" present in 2023 410.184.)
410.186 — Support Fittings (NEW) Fittings identified for support of horticultural lighting equipment shall be used in accordance with the installation instructions provided and shall be securely fastened.2023: on-disk 2023 row 410.186 - quoted verbatim
Part XVII — Germicidal Irradiation (410.191-410.197) — NEW in 2023
Delta D30 - NEW Part XVII (410.191-410.197): germicidal irradiation — zero of these tokens in the on-disk 2017 scan - 2023 adds an entire Part XVII for luminaires that emit germicidal (UV-C) irradiation. 410.191 requires the luminaire be listed and identified as germicidal equipment; 410.193 install per the manufacturer's instructions and markings; 410.195 (A)-(D) — not for general illumination unless indicated, not where subject to physical damage, not in a dwelling unless listed for dwellings, and not mounted below the minimum height specified by its listing in an occupied-during-operation space; and 410.197 (A)-(D) — a "germicidal irradiation system" intended to safeguard against UV exposure by ensuring the space is unoccupied during operation shall be listed and identified as a germicidal system, with all components provided by the system manufacturer or clearly specified, installed per the listing, and not in a dwelling unless listed. (Machine-verified: "410.191" through "410.197" have no on-disk 2017 sections; the on-disk 2017 Article 410 region has zero germicidal tokens.)
410.191 — Listing (NEW) Luminaires intended to emit germicidal irradiation shall be listed and identified as germicidal equipment.2023: on-disk 2023 row 410.191 - quoted verbatim
410.193 — Installation (NEW) Luminaires shall be installed in accordance with the manufacturer's instructions and equipment markings.2023: on-disk 2023 row 410.193 - quoted verbatim
410.195 — Installation Restrictions (NEW, (A)-(D)) Luminaires shall not be installed as lighting for general illumination unless such use is indicated in the manufacturer's instructions. Luminaires shall not be installed where likely to be subject to physical damage. Luminaires shall not be installed in a dwelling unless listed and identified for use in dwellings. Luminaires installed in a building space that will be occupied during luminaire operation shall not be mounted below the minimum height specified by its listing and installation instructions.2023: on-disk 2023 rows 410.195(A)-(D) - quoted verbatim
410.197 — Germicidal Irradiation Systems (NEW, (A)-(D)) A germicidal irradiation system intended to provide a safeguard against UV exposure by ensuring that a building space will not be occupied during luminaire operation shall be listed and identified as a germicidal system. All system components shall be provided by the system manufacturer or clearly specified in the installation instructions as a component that the installer is required to source separately. A germicidal irradiation system shall be installed in accordance with the manufacturer's installation instructions and installation markings. A germicidal irradiation system shall not be installed in a dwelling unless listed and identified for use in dwellings.2023: on-disk 2023 rows 410.197(A)-(D) - quoted verbatim
The 32 machine-diffed 2017→2023 deltas (D1-D32), at a glance
#
Section
What moved 2017 → 2023
D1
410.2
Section repurposed: 2017 "Closet Storage Space" definition → 410.16(A); 2023 410.2 = NEW reconditioned-luminaire/retrofit ban
D2
410.10(D)
"ceiling-suspended (paddle) fans" → "...with luminaire (light kit)" in the tub/shower zone
D3
410.10(F)
New Exception: 38 mm roof-deck spacing not required over a ≥50 mm concrete slab
D4
410.16
Absorbs old 410.2 definition as (A); recessed-incandescent clearance corrected 180→150 mm (6 in.)
D5
410.22
Cover exception: "receptacle" → "receptacle that covers the box or is provided with a faceplate"
D6
410.36(A)
Adds 314.27(E) support + "314.27(E) boxes = lighting outlets per 210.70(A),(B),(C)"
D7
410.40
"grounded per Article 250 and Part V" → "connected to an EGC per Part V"
Test-standard refs updated (ASTM E84-20 / UL 723-2018); recessed range → 410.126
D24
410.137(C)
Adds "LED driver(s)"; "Article 348" → "Part II of Article 348"; + voltage-rating condition
D25
410.141(B)
"lockable" → "lockable open" per 110.25
D26
410.151→150
Renumbered; load-calc cite 220.43(B) → 220.46(B)
D27
410.155(B)
"grounded per Article 250" → "connected to the EGC per Part V"
D28
410.170-186
NEW Part XVI: horticultural lighting (listing, uses, cord, EGC, GFCI/SPGFCI, supports)
D29
410.184
NEW: cord-connected horticultural lighting → listed GFCI (SPGFCI >150 V to ground, UL 943C)
D30
410.191-197
NEW Part XVII: germicidal irradiation (listing, installation, restrictions, UV-safeguard systems)
D31
410.56
Info Note reworded: "For approved means...see 110.14" → "See 110.14 for approved means..."
D32
410.140
2017 "For signs and outline lighting, see Article 600" Informational Note deleted
Machine-counted scope: the on-disk Mike Holt 2023 change summary carries exactly four in-scope Article 410 entries — 410.10 (bathtub/shower light-kit + roof-deck), 410.42 (condensed + Exception, title changed), 410.71 (relocated from 410.130(G), now covers LED), and 410.184 (GFCI/SPGFCI horticultural, printed in the MH file under the Article 450 region) — so the rest of the 32 deltas are direct on-disk 2017-scan ↔ 2023-dataset diffs, not summary-sourced claims. 2020 edition gap (honest scope): the on-disk 2020 source (slideshare scan) carries no Article 410 body — its on-disk article headings are 90, 100, 110, 200, 210, 215, 220, 225, 230, 240, 250, 430, 440, 450, 518, 600, 685, 705, 770 (Article 410 is not among them), and its only Article-410 tokens are in-text cross-references (410.93, 410.104(B), 410.117, 410.137, 410.62(C), 410.90) from within other articles' switching/tap provisions (no Article 410 section body — machine-asserted) — so no 2020 position is asserted anywhere on this page; the edition story is 2017 ↔ 2023, both sides on disk. 27 sections are verified word-identical 2017→2023 (21 at the same number + 6 renumbered: 410.48→50, 410.50→51, 410.103→100, 410.118→120, 410.121→124, 410.122→126), identical modulo the 2017 scan's line-hyphenation, the 2017 "410.XX Title." lead-in (omitted by the 2023 dataset), and the 2023 dataset's flattening of (A)/(B) sub-headers (machine-verified: the 2023 section text matches the 2017 section body exactly once those formatting differences are removed). The 2017 scan's disclosed OCR artifacts (each machine-asserted in the verify script): "Cleai-type" (410.5), the "disconnec-410.10-tion" mid-word leak (410.8), the "FIGURE 410.2 Closet Storage Space" caption bleed in (D) (410.10), "1% in." for "1½ in." (410.10(F), 410.42), "180 mm (6 in.)" for the recessed value (410.16, an erratum corrected in 2023), "Cord-Gonnected" (410.59), "ofa ballast" (410.68), "13 mm (% in.)" (410.116), "6 mm (% in.)" (410.120/410.146), "shail" for "shall" (410.130), "de" for "dc" (410.134), the 410.62 bushing-fraction garbage, and the 410.36 last-note truncation — none change the substance of a rule; the 2023 dataset resolves them.
Six worked examples (every number from the real shipped PanelWright core, zero hand math)
EX1 - the 410.30(A) screw-shell support limit (3 kg / 6 lb)
410.30(A) (unchanged 2017→2023): "A luminaire that weighs more than 3 kg (6 lb) or exceeds 400 mm (16 in.) in any dimension shall not be supported by the screw shell of a lampholder." For a 3.6 kg luminaire: the 3.6 kg ÷ 3 kg limit = 1.2× the threshold (≈ 7.94 lb) — over the 3 kg / 6 lb ceiling, so it must be supported by a box/fittings, not the lampholder screw shell. (Direct arithmetic on the on-disk 3 kg / 6 lb rule; the 400 mm / 16 in. dimension test applies equally.)
on-disk 410.30(A) limit = 3 kg (6 lb); 3.6 kg ÷ 3 kg = 1.2× (≈ 7.94 lb) → screw-shell support NOT permitted
410.16(D) (2023) sets the minimum clearance from recessed luminaires to the nearest point of the clothes-closet storage space. The 2017 erratum printed 180 mm (≈ 7.09 in.) for recessed incandescent/LED luminaires; 2023 corrects it to 150 mm (≈ 5.91 in.) — a 30 mm reduction. For the 12 in. surface-mounted case the 2017 value (300 mm) equals the 2023 304.8 mm (12 in. × 25.4). The clearance is the on-disk rule value; the only 2017→2023 change is the 180→150 mm fix.
2017 (erratum) = 180 mm (≈ 7.09 in.); 2023 = 150 mm (≈ 5.91 in.); reduction = 30 mm; 12 in. = 304.8 mm
EX3 - the 410.150(B) lighting-track load cap (20 A track @ 120 V, 12 × 250 VA fittings)
410.150(B) (2023, was 410.151(B)): "The connected load on lighting track shall not exceed the rating of the track." A 20 A track at 120 V caps at 20 × 120 = 2400 VA. Load 12 fittings × 250 VA = 3000 VA; 3000 ÷ 120 = 25 A. That exceeds the 20 A track rating by 5 A — the connected load violates 410.150(B). (Note 410.150(B) also says the 220.46(B) load calculation "shall not be required to limit the length of track" — the track's own ampere rating, not the dwelling lighting load, is the governing cap here.)
core: 20 A × 120 V = 2400 VA cap; 12 × 250 VA = 3000 VA = 25 A → OVER the 20 A track (violates 410.150(B))
EX4 - the 410.62(C)(2) mogul-base 50 A branch-circuit cap vs the 125 % plug rule
410.62(C)(2) (2023): "Electric-discharge luminaires provided with mogul-base, screw shell lampholders shall be permitted to be connected to branch circuits of 50 amperes or less by cords complying with 240.5. Receptacles and attachment plugs shall be permitted to be of a lower ampere rating than the branch circuit but not less than 125 percent of the luminaire full-load current." For a 32 A full-load ED luminaire: 32 × 125% = 40 A minimum plug/receptacle rating. On a 50 A branch circuit (the 410.62(C)(2) ceiling for this mogul-base cord connection): 40 A ≤ 50 A, so the plug/receptacle requirement is satisfiable — a 32 A full-load luminaire may cord-connect on a ≤50 A circuit. (Had the full-load current been 41 A, the 125 % minimum would be 51.25 A — above the 50 A circuit ceiling, and the mogul-base cord path would be unavailable for that load.)
410.62(C)(2): branch circuit ≤ 50 A; 32 A FL × 125% = 40 A minimum plug/receptacle rating (≤ 50 A cap ✓)
EX5 - the 410.68 90 °C rule: a 30 A circuit within 75 mm of a ballast (insulation rating, not ampacity)
410.68 (unchanged 2017→2023): "Feeder and branch-circuit conductors within 75 mm (3 in.) of a ballast, LED driver, power supply, or transformer shall have an insulation temperature rating not lower than 90 °C (194 °F), unless supplying a luminaire marked as suitable for a different insulation temperature." Note what this is — and is not: it sets a minimum insulation rating for the conductors, it does not let you size the circuit from the 90 °C ampacity column. For a 30 A copper circuit with 75 °C-rated terminations, the shipped core's pickConductor31016(30, 'cu', 75) = 10 AWG Cu (75 °C column, 35 A) is the sizing pick (per 110.14, terminations rated 75 °C use the 75 °C column), and the pickConductor31016(30, 'cu', 90) = 12 AWG (30 A) 90 °C-column value is not usable to size this 30 A circuit. So a compliant 410.68 install of a 30 A circuit routed within 75 mm of the ballast is 10 AWG 90 °C-rated (THHN/THWN-2) insulation: sized on the 75 °C column (35 A ≥ 30 A) and carrying the 90 °C insulation 410.68 demands. A 75 °C-rated (THW/TW) wire would fail 410.68 inside the 75 mm zone regardless of size.
410.68 (75 mm of ballast): insulation ≥ 90 °C required; core: pickConductor31016(30, cu, 75) = 10 AWG (35 A, sizing) vs pickConductor31016(30, cu, 90) = 12 AWG (30 A, NOT usable - 75 °C terminations) → use 10 AWG THHN (90 °C insulation)
EX6 - Part XVI horticultural: 12 × 50 W cord-connected fixtures, GFCI per 410.184
A horticultural install with 12 × 50 W cord-connected luminaires on a 120 V branch circuit: 12 × 50 = 600 W; 600 ÷ 120 V = 5 A; the shipped core's nextStdBreaker(5) = 15 A. Because the horticultural lighting is cord-connected with separable connectors/attachment plugs, 410.184 requires the supplying lighting outlets be protected by a listed GFCI (or a listed SPGFCI if the circuit exceeds 150 V to ground, per UL 943C). The small load (15 A OCPD) is the circuit side; the GFCI/SPGFCI requirement is the 2023 Part XVI protection rule that did not exist in 2017.
12 × 50 W = 600 W ÷ 120 V = 5 A → nextStdBreaker = 15 A; 410.184: cord-connected horticultural → listed GFCI (SPGFCI >150 V to ground)
Frequently asked questions
Q: What does Article 410 actually cover?
Luminaires, portable luminaires, lampholders, pendants, incandescent filament lamps, arc lamps, electric-discharge lamps, decorative lighting products, lighting accessories for temporary seasonal and holiday use, and portable flexible lighting products — and the wiring and equipment forming part of such products and lighting installations (410.1). In 2023 the article runs to 17 parts, adding Part XVI horticultural lighting (410.170-410.186) and Part XVII germicidal irradiation (410.191-410.197). Design aid only — the adopted edition governs.
Q: What changed in Article 410 from 2017 to 2023?
32 machine-diffed deltas plus a full renumbering. The structural moves: a brand-new Part XVI horticultural (410.170-410.186) and Part XVII germicidal (410.191-410.197); a 9-section renumbering (410.48→50, 410.50→51, 410.74→80, 410.103→100, 410.118→120, 410.120→122, 410.121→124, 410.122→126, 410.151→150); the drop of 410.46 (folded into 410.42/410.44). Substantive rewrites: 410.42 (exposed conductive surfaces + 3 exceptions), 410.10(D) (ceiling fans with light kits in the tub/shower zone), 410.10(F) (concrete-slab exception), 410.16 (closet definition absorbed; 180→150 mm), 410.82 (handlamps deleted), 410.130 (disconnecting means → 410.71), 410.151→150 (220.43→220.46). 27 sections are word-identical.
Q: What are the new 2023 Part XVI (horticultural) and Part XVII (germicidal)?
Part XVI (410.170-410.186) governs horticultural lighting: Parts I-XII luminaires permitted (410.170), listed (410.172), installed per the listing (410.174), not for general illumination / not where damaged or concealed (410.176), cord-connected only as part of listed equipment (410.178-410.180), EGC per Part V (410.182), and — the headline — cord-connected horticultural lighting with separable connectors/attachment plugs requires listed GFCI, or listed SPGFCI over 150 V to ground (410.184, UL 943C). Part XVII (410.191-410.197) governs germicidal-irradiation luminaires: listed + identified (410.191), installed per the listing (410.193), not for general illumination / not damaged / not dwellings / min height (410.195), and a UV-occupancy-safeguard "germicidal system" listed with manufacturer components (410.197). Both parts are absent from the on-disk 2017 scan.
Q: Why did 410.46 disappear in 2023?
2017 410.46 required luminaires with exposed metal parts to have a means for connecting an equipment grounding conductor. In 2023 that rule is folded into the rewritten 410.42 (exposed conductive surfaces shall be connected to an EGC, with three exceptions) and 410.44 (the mechanical-connection methods + replacement-luminaire exceptions). There is no 410.46 row in the 2023 dataset — machine-verified.
Sources & verification method
2017 text: on-disk official NFPA 70 (2017 NEC) scan, Article 410 region (lines 47209-48641 of the flat extraction — ARTICLE 410 Part I heading at 47209, ARTICLE 420 boundary at 48641), machine-reflowed into 68 top-level sections (Parts I-XV; last section 410.160) (s96_410_2017_sections.json). Disclosed OCR/scan artifacts (each machine-asserted in the verify script): "Cleai-type" for "Cleat-type" (410.5); the "disconnec-410.10-tion" mid-word running-header leak (410.8); the "FIGURE 410.2 Closet Storage Space" caption printed mid-sentence in (D) (410.10); "1% in." for "1½ in." (410.10(F), 410.42); "180 mm (6 in.)" for the recessed-incandescent value (410.16, an erratum corrected to 150 mm in 2023); "Cord-Gonnected" for "Cord-Connected" (410.59); "ofa ballast" for "of a ballast" (410.68); "13 mm (% in.)" for "13 mm (1/2 in.)" (410.116); "6 mm (% in.)" for "6 mm (1/4 in.)" (410.120, 410.146); "shail" for "shall" (410.130); "de" for "dc" (410.134); the 410.62 bushing-hole fraction garbage ("%: in." / "'%p» in."); and the 410.36 last Informational Note truncated at "protection of conductors,". None change the substance of a rule.
2023 text: on-disk 2023 NEC dataset (art35_nec_csv.csv), all 164 Article 410 rows = the complete article in the dataset (83 sections, 410.1 through 410.197, Parts I-XVII; 57 top-level rows + 26 sub-only sections). Disclosed 2023 dataset artifacts: the list-item concatenation (list items print run-together in 410.10/410.16/410.59/410.130/410.150/410.178/410.195/410.197), the "GECI" variant of "GFCI" (410.44), the "lighting (rack" typo for "lighting track" (410.150(D)), and the antflix per-section citation links (stripped for clean quoting).
Mike Holt 2023 change summary: on-disk (art48_mh23cc_full.txt) — exactly four in-scope Article 410 entries (machine-counted): 410.10 (bathtub/shower light-kit + roof-deck), 410.42 (condensed into parent text + Exception, title changed), 410.71 (relocated from 410.130(G), now covers LED), and 410.184 (GFCI/SPGFCI horticultural — printed in the MH file under the Article 450 region, misplaced but in-scope). All 32 deltas are otherwise direct on-disk diffs, not summary claims.
2020 edition gap: the on-disk 2020 source (slideshare scan) carries no Article 410 body — its on-disk article headings are 90, 100, 110, 200, 210, 215, 220, 225, 230, 240, 250, 430, 440, 450, 518, 600, 685, 705, 770 (no Article 410), and its only Article-410 tokens are in-text cross-references (410.93, 410.104(B), 410.117, 410.137, 410.62(C), 410.90) from other articles (no Article 410 section body — machine-asserted) — so no 2020 position is asserted.
Worked examples: every number computed by the shipped PanelWright core (nextStdBreaker, pickConductor31016, round2) under node (art71_numbers.json), plus direct arithmetic on on-disk rule values (the 410.30(A) 3 kg / 6 lb limit, the 410.16 180→150 mm clearance, the 410.150(B) track VA cap, the 410.62(C)(2) 50 A / 125 % rules, the 410.68 75 mm / 90 °C rule, the Part XVI 410.184 GFCI) — zero hand math; the test suite re-runs the core and compares.
Verification:verify_art71.py runs the machine checks (all 164 2023 rows present, all 68 2017 sections present, the 32 deltas both-sided, the 27-section word-identity set (modulo the 2023 sub-header flattening / 2017 title + hyphenation), the zero-hit absence claims for Parts XVI/XVII + 410.46/410.69/410.71/410.118-new in 2017, the 2020-gap token absence, the worked figures, the core re-run, the sitemap/index/README entries, tag balance) — the count in the footer is the script's actual total, and a self-consistency check prevents the page from claiming a number the verifier does not run. N machine-verified checks — all N pass.
Scope & honesty: this is a design aid, not code commentary and not engineering advice. The adopted edition in your jurisdiction governs. Where 2017 and 2023 differ, the delta boxes say what moved; where a number is quoted from a scan, the disclosed OCR artifacts are listed. AI-built, AI-verified, fully disclosed.