8.5 Switches, Receptacles & Luminaires

8.5 Switches, Receptacles & Luminaires

Quick Reference: The ICC E3 outline lists Switches, Receptacles, and Lighting Fixtures as a distinct job task inside Equipment for General Use: determine code compliance of lighting fixtures, type and rating of receptacles, switches, and disconnects. Three NEC articles carry it — 404 (Switches), 406 (Receptacles, Cord Connectors, and Attachment Plugs), and 410 (Luminaires, Lampholders, and Lamps). These are low-glamour articles that reliably produce exam questions because the numbers are crisp and the traps are geometric.

1. Switches (NEC Article 404)

Mounting and access

NEC 404.8(A) requires all switches and circuit breakers used as switches to be installed so that the center of the grip of the operating handle, when in its highest position, is not more than 6 ft 7 in. (2.0 m) above the floor or working platform. This is the same dimension as 240.24(A) for overcurrent devices — one number, two articles.

The neutral at the switch (NEC 404.2(C))

Switches controlling lighting loads must have the grounded circuit conductor provided at the switch location. The rule exists so that modern electronic dimmers, occupancy sensors, and smart switches have a return path and do not have to leak current through the equipment grounding conductor. Recognized exceptions include:

• Conductors enter the box through a raceway that has capacity to accommodate an added grounded conductor.
• Conductors enter the box through a cable assembly with spare conductors or through a framing cavity open at the top or bottom on the same floor level, so a neutral can be added without removing finish.
• The switch is a lighting control device other than a snap switch — for example a listed control that does not require a neutral.
• The box is a snap switch with integral enclosure complying with 300.15(E).

Ratings (NEC 404.14)

An AC general-use snap switch may control:

That 80 percent motor derating is the number examiners test. A 20 A AC general-use snap switch used as a motor controller is limited to a 16 A motor full-load current.

Grounding of snap switches (NEC 404.9(B))

Snap switches, including dimmers and similar control switches, must be connected to an equipment grounding conductor and must provide a means to connect metal faceplates. Where no equipment grounding conductor exists in the box in an existing installation, a replacement snap switch is permitted if the wiring method is GFCI-protected or the switch is provided with a nonmetallic faceplate that cannot be installed on another type of switch.

2. Receptacles (NEC Article 406)

Damp versus wet locations — the cover test (NEC 406.9)

This is the most frequently missed distinction in Article 406, and it is decided by one question: does the cover have to be weatherproof with a plug inserted?

+-----------------------------------------------------------------------------+
|                 RECEPTACLE ENCLOSURE COVERS (NEC 406.9)                     |
+-----------------------------------------------------------------------------+
|  DAMP LOCATION  (406.9(A))                                                  |
|    Enclosure weatherproof when the attachment plug cap is REMOVED.          |
|    A self-closing lift-lid cover is acceptable.                             |
|    Example: under a roofed open porch, protected from beating rain.         |
|                                                                             |
|  WET LOCATION   (406.9(B)(1))                                               |
|    15 A and 20 A, 125 V and 250 V receptacles:                              |
|    Enclosure weatherproof WHETHER OR NOT the plug is inserted.              |
|    Requires a listed WHILE-IN-USE (in-use / bubble) cover.                  |
|                                                                             |
|  WET LOCATION   (406.9(B)(2))                                               |
|    Other receptacle ratings: weatherproof cover when the plug is removed,   |
|    and the outlet must not be used for portable tools/appliances unless      |
|    the enclosure is weatherproof with the plug inserted.                     |
+-----------------------------------------------------------------------------+

NEC 406.9(C) additionally prohibits receptacles from being installed within or directly over a bathtub or shower stall, and 406.9(E) prohibits installing a receptacle face up in a countertop or similar work surface unless it is part of an assembly listed for that application. NEC 406.5(E) and (F) carry the parallel prohibitions on face-up mounting in countertops and in seating or similar surfaces.

Tamper-resistant receptacles (NEC 406.12)

All nonlocking-type 15- and 20-ampere, 125-volt and 250-volt receptacles in the listed occupancies must be listed tamper-resistant. The list includes dwelling units, hotel and motel guest rooms and guest suites, child care facilities, preschools and elementary education facilities, business offices and corridors and waiting rooms in clinics and medical and dental offices, subsidized and public housing, dormitories, and assisted living facilities. Recognized exceptions include receptacles more than 5 1/2 ft above the floor, receptacles that are part of a luminaire or appliance, and a single or duplex receptacle in a dedicated space for an appliance that in normal use is not easily moved.

Replacement obligations (NEC 406.4(D))

When an existing receptacle is replaced, the replacement must be brought forward to current requirements: GFCI where 210.8 now requires it, AFCI where 210.12 now requires it, tamper-resistant where 406.12 applies, and weather-resistant where 406.9(B) applies. Where no equipment grounding conductor exists, 406.4(D)(2) permits a non-grounding-type replacement, a GFCI marked "No Equipment Ground," or a grounding-type receptacle supplied through a GFCI and marked "GFCI Protected" and "No Equipment Ground."

3. Luminaires (NEC Article 410)

Bathtub and shower zones (NEC 410.10(D))

No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans may be located within a zone measured 3 ft horizontally and 8 ft vertically from the top of the bathtub rim or shower stall threshold. Luminaires that are located within the actual bathtub or shower area must be listed for damp locations, or listed for wet locations where subject to shower spray. On a residential or hotel plan review, this is checked by scaling the reflected ceiling plan against the plumbing fixture plan — a pendant over a soaking tub is the single most common rejection.

Clothes closets (NEC 410.16)

NEC 410.2 defines the storage space in a closet: the volume bounded by the sides and back closet walls extending from the floor to a height of 6 ft or to the highest clothes-hanging rod, and extending 24 in. horizontally from the back and side walls (or the shelf width where wider), plus the volume above that height extending 12 in. or the shelf width.

Prohibited (410.16(B)): incandescent or LED luminaires with open or partially enclosed lamps, and pendant luminaires or lampholders.

Minimum clearance to the nearest point of the storage space (410.16(C)):

Recessed luminaire clearances (NEC 410.116)

• Non-Type IC: the enclosure must be spaced not less than 1/2 in. from combustible material, except at the point of support, and thermal insulation must be kept not less than 3 in. from the enclosure and must not be installed above the luminaire in a way that traps heat.
• Type IC: the luminaire is identified for insulation contact and may be in direct contact with insulation and combustible material.

Luminaire and fan support

Outlet boxes used as the sole support for a ceiling-suspended (paddle) fan must be listed and marked for that application and marked with the maximum weight supported where the fan exceeds 35 lb (NEC 314.27(C)); the general limit for a listed fan-rated box is 70 lb. A standard outlet box listed only for luminaire support may not carry a fan, and a plan note calling for "fan-rated box" at every fan location is what a plans examiner should be looking for on the reflected ceiling plan.

4. Worked Plan Review: Hotel Guest Room Fit-Out

Submittal: A 140-key hotel renovation. Guest room drawings show (a) a pendant luminaire centered 2 ft 6 in. horizontally from the bathtub rim at a 7 ft mounting height, (b) standard nonlocking 15 A 125 V duplex receptacles throughout the guest rooms, (c) a surface-mounted LED closet luminaire with a completely enclosed source mounted on the ceiling 9 in. from the front edge of the shelf, (d) a 20 A AC general-use snap switch specified as the controller for an 18 A exhaust fan motor, and (e) exterior balcony receptacles with self-closing flip covers.

Findings:

1. 410.10(D) violation. A pendant luminaire at 2 ft 6 in. horizontal and 7 ft vertical is inside the 3 ft by 8 ft prohibited zone. Replace with a listed damp-location surface or recessed luminaire outside the zone.
2. 406.12 violation. Hotel and motel guest rooms and guest suites are a listed tamper-resistant occupancy. All nonlocking 15 A and 20 A, 125 V receptacles must be listed tamper-resistant.
3. 410.16(C)(1) violation. A surface-mounted LED luminaire with a completely enclosed source requires 12 in. to the nearest point of the storage space; 9 in. is short. Either relocate the luminaire or specify a recessed unit, which is permitted at 6 in.
4. 404.14(A) violation. An AC general-use snap switch controlling a motor load is limited to 80 percent of its rating: 20 A x 0.80 = 16 A. An 18 A motor exceeds it. Specify a 30 A switch or a listed motor-rated controller.
5. 406.9(B)(1) violation. An open balcony is a wet location. A self-closing flip cover is a damp-location device; the balcony receptacles require a listed while-in-use cover that is weatherproof with the plug inserted.

5. Plans Examiner Verification Checklist: Switches, Receptacles & Luminaires

• Switch height: Operating handle center <= 6 ft 7 in. above the floor or working platform (404.8(A)).
• Neutral at switch: Grounded conductor provided at lighting switch locations, or an applicable 404.2(C) exception is documented on the drawings.
• Snap switch motor loading: Motor loads limited to 80 percent of the switch rating (404.14).
• Receptacle covers: Damp locations weatherproof with plug removed (406.9(A)); wet locations weatherproof with plug inserted for 15 A and 20 A, 125 V and 250 V devices (406.9(B)(1)).
• Tamper-resistant: Specified for dwelling units, guest rooms and suites, child care, preschool and elementary, medical and dental waiting areas, dormitories, and assisted living (406.12).
• No face-up receptacles in countertops or work surfaces unless part of a listed assembly (406.5(E), 406.9(E)); none within or over a bathtub or shower stall (406.9(C)).
• Bathtub/shower zone: No pendants, track, cord- or chain-suspended luminaires, or paddle fans within 3 ft horizontally and 8 ft vertically (410.10(D)).
• Clothes closets: No open or partially enclosed lamps or pendants; clearances of 12 in. or 6 in. by type verified against the storage space (410.16).
• Recessed luminaires: Type IC specified wherever insulation contact occurs; otherwise 1/2 in. combustible clearance and 3 in. insulation clearance shown (410.116).
• Fan support: Outlet boxes at ceiling-suspended fans listed and marked for fan support, with weight marking above 35 lb (314.27(C)).