Jim Dollard has an extensive background in codes and standards. Send questions about the National Electrical Code (NEC) to Jim at [email protected]. Answers are based on the 2023 NEC.

Attic lighting

A new church/school has an attic space accessible with pull-down stairs. It is a large space, and the only electrical wiring required on the approved drawings is five attic ventilation fans. Is lighting required?

Yes, Part III of Article 210 provides requirements for outlets. See Section 210.70 for required lighting outlets. Section 210.70(C) applies to spaces in all occupancies and includes attics, underfloor spaces, utility rooms and basements. Where these spaces are used for storage or contain equipment requiring servicing, such as the ventilation fans referenced in your question, at least one lighting outlet containing a switch or controlled by a wall switch or listed wall-mounted control device must be installed.

Accessible conduit bodies

An architect decided at the end of a project that they did not want to see exposed raceways supplying lighting in a large gymnasium. Their intent is to build a false wall that will cover multiple conduit bodies. We would have to reach down 18 inches for access. Is that compliant?

No, see the general rule in Section 314.29 that requires conduit bodies be installed so the wiring inside is accessible. The completed installation must allow access to the conduit body to remove or replace the conductors installed. As described in your question, an installer would not be able to gain access to remove or replace conductors. The building finish would have to be damaged to gain access, and holes would have to be cut in the drywall just to access the cover on the conduit body. The term “accessible” as applied to wiring methods (including the conductors installed) is defined as capable of being removed or exposed without damaging the building structure or finish.

Physical damage

A punch list item identified that EMT was used to protect a grounding electrode conductor on a loading dock without bonding at both ends. Can we use PVC conduit instead?

Yes, rigid PVC conduit is permitted. In this installation, there is obviously a need for physical protection of the grounding electrode conductor as it is located on a loading dock. Where rigid PVC conduit is subject to physical damage, schedule 80 PVC conduit and elbows are required.

Energy management system

A new tenant is moving into a commercial space in a large multiuse structure separated into many occupancies. The municipality wants load calculations and drawings. The existing feeder is just short of Article 220 requirements with respect to the calculated load. Can we apply energy management to implement load shedding when necessary and reuse the existing feeder?

Yes, it is permitted under certain criteria outlined in the NEC. Part III of Article 220 addresses load calculations for feeders. The last requirement in Part III, Section 220.70 provides permissive requirements for an energy management system (EMS) in cases such as this one. 

An EMS is permitted to limit the load on a feeder provided it is done in accordance with Section 750.30. The maximum ampere set point of the EMS can be used in the load calculation for the feeder. The set point value of the EMS is considered a continuous load. The feeder conductors must be sized accordingly. See Section 750.30 for equipment/system loads that are not permitted to be load shed, such as fire pumps and emergency systems. Additional requirements mandate that the EMS not disconnect loads such as elevators, escalators and circuits supplying emergency lighting.

Mini split AC unit in bathroom?

In a very large dwelling unit bathroom, the owner wants a mini split AC unit installed next to a tub for aesthetic reasons. It will be 2 feet away and 6 feet high to the bottom, not over the tub. Is that OK?

No, the AC unit is not permitted to be in the space directly over the tub or within 3 feet horizontally and 8 feet vertically from the top of a bathtub rim. See Section 440.8.

Meter enclosure under window?

An inspector required us to relocate a meter because it was under a window. We moved it just to get done but cannot find such a requirement in the NEC. Can you help?

The NEC does not contain a requirement that would prohibit the installation of a meter enclosure under a window. It is likely that the local electric utility company does prohibit such an installation. This is due to homeowners or their children attempting to use the meter enclosure as a step or ladder to climb through or to clean the window. Typically, the utility company is notified by the inspection agency that the service installation is NEC compliant and is ready to energize. Electrical inspectors are familiar with local requirements and will fail an installation if they do not comply with the local utility requirements. It is extremely important to know those requirements.

Replacement panelboards?

Is it permitted to just replace the interior of a recessed panelboard? It is in a commercial kitchen, and we cannot get GFCI circuit breakers necessary for new equipment.

Yes, replacement panelboards are permitted in existing enclosures provided you meet the requirements of Section 408.9. The best path forward is to locate a replacement panelboard that is listed for the specific enclosure already installed in the kitchen. This is permitted in 408.9(A). If you cannot locate a listed replacement panelboard, 408.9(B) permits the installation if the available fault current at the panelboard is not greater than 10 kA. If the available fault current exceeds 10 kA, the installation must be field labeled.

Class I, Division 2 locations

In Class I, Division 2 locations, can we use threadless RMC couplings and connectors? Does every box and conduit body need seal-offs?

Yes, threaded or threadless fittings for RMC or IMC are permitted in Class I, Division 2 locations provided they are listed. See Section 501.10(B)(1). Conduit seals for these locations are required in accordance with 501.15(B). Required seals include, but are not limited to, enclosures that contain equipment or devices that can produce arcs or temperatures that exceed 80% of the auto-ignition temperature in Celsius of the gas or vapor involved. This would include, but not be limited to, enclosures containing switches, circuit breakers, fuses, relays or resistors.

It is important to note that where seals are installed in Class I, Division 2 locations, all the conduit run or nipple between the seal and enclosure must be wiring methods required in Class I, Division 1 locations in compliance with 501.10(A). Listed threadless RMC couplings and connectors are prohibited between the seal and the explosion­-proof enclosure. 

Conduit seals are required to be installed within 18 inches from the enclosure or as required by the enclosure marking. Only threaded couplings or explosion-proof fittings are permitted between the sealing fitting and the explosion-proof enclosure. Seals are also required in each conduit run leaving a Class I, Division 2 location; see 501.15(B)(2).

AC cable, EGC?

Existing home runs of Type AC cable are identified to be reused as part of a renovation. We are having an internal debate as to the AC cable being compliant. It is in good shape but no equipment grounding conductor (EGC) is in the cable. Is that permitted?

Yes, see Section 250.118, list item (8), which recognizes the armor of Type AC cable as an EGC as provided in 320.108. This section is in Article 320, Part III, Construction Specifications, and requires Type AC cable to provide an adequate path for fault current as required by 250.4(A)(5) or (B)(4) to act as an EGC. 

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