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 2020 NEC.

Grow facility requirements

Are there any special Code requirements that would apply to a cannabis grow facility?

All of the requirements of the NEC will apply to these installations. The only specific Code requirements applicable to these venues were added in Article 410, “Luminaires, Lampholders, and Lamps,” in the 2020 revision cycle for a new Part XVI, Special Provisions for Horticultural Lighting Equipment. The informational note following 410.170 clarifies that lighting equipment identified for horticultural use is designed to provide a spectral characteristic needed for plant growth and can also provide supplemental general illumination within the growing environment. Horticultural lighting must be listed. There are 12 sections in this new part of Article 410 to address requirements that apply only to horticultural lighting.

Replacement pool pump motors

Are replacement pool pump motors required to be protected by GFCI? The local municipality only requires that a replacement pump motor be listed for the purpose, and, if no GFCI protection exists, none is required.

Yes, Section 680.21(D) requires pool pump motors replaced for maintenance or repair to be provided with GFCI protection. This section references 680.21(C), which requires all outlets supplying pool motors, single or three-phase, rated 150V or less to ground and 60A or less, be GFCI-protected. This includes the replacement of all hardwired and cord/plug-connected pool pump motors.

Feeders for pools

I stopped one of my crews installing SER cable for a panelboard in the garage of a home that would then supply receptacle outlets in the garage and branch circuits for an outdoor swimming pool. It was my understanding that a feeder to a pool must have an insulated equipment grounding conductor. Did that change?

Yes, significant clarity was provided in the 2017 NEC revision cycle. Section 680.25 provides requirements for any feeder on the supply side of panelboards supplying branch circuits for pool equipment. The 2014 NEC did not permit type SER cable. The revised requirement in 2017, which remains the same in 2020, requires feeders to comply with the general requirements in Chapter 3 where they are installed in noncorrosive environments. This would permit type SER cable in a noncorrosive environment.

Fire pump sources

The plan review on a warehouse project noted that the fire pump as seen on the drawing was in violation of the NEC. The note on the drawing stated that the service was not reliable because the utility company will not go on record and document the reliability of the service. That just doesn’t make sense. The note states that, in addition to the service, we must install an on-site generator. Is this correct?

The inspector is correct. A fire pump can be supplied from a single source only where it is a reliable source of power. When applying the requirements for fire pumps, it is important to understand that the NEC only provides installation rules to meet the performance requirements in Chapter 9 of NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection. See the informational note (IN) following 695.1(A), which explains that text followed by a reference in brackets has been extracted from NFPA 20.

However, not all of the extracted requirements have such references because the text was modified to meet NEC style. The NEC requirement for a reliable source of power is found in 695.3 (no NFPA 20 reference in brackets), which contains rules for permitted sources and arrangements to supply electric motor-driven fire pumps. This is derived from the performance-based requirement in NFPA 20 Section 9.3.2.

In most cases, the electric utility will not go on record as a reliable source. The IN following the parent text in Section 695.3 sends the code user to NFPA 20 Section 9.3.2 and annex material in A.9.3.2 for guidance on the determination of power source reliability.

NFPA 20 does not require an infallible source, just a reliable one. For example, the annex material explains that a service connection supplied by overhead conductors cannot be considered reliable because firefighters will have overhead lines deenergized before using an aerial apparatus. Most fire pump installations are supplied in accordance with 695.3(B), Multiple Sources. The most common arrangement is a service [695.3(A)(1)] or a dedicated feeder [695.3(A)(3)] and an on-site standby generator as permitted in 695.3(B)(2).

Dishwashers and GFCI protection

What happened to the requirement to put dishwashers on a GFCI? It is no longer in 210.8. Is it still required?

GFCI requirements for dishwashers are modified and significantly expanded in the 2020 NEC . The previous requirement was in 210.8(D) and mandated GFCI protection for dishwashers, but only in dwelling units. This requirement has been relocated into Article 422, Appliances. Section 210.8(D) is now Specific Appliances, and it sends the Code user to Article 422 for appliance GFCI requirements. See 422.5(A) that expands GFCI requirements for dishwashers to all occupancies. Where rated 150V or less to ground and 60A or less, single- or three-phase, the appliances listed in 422.5(A)(1) through (A)(7) must be provided with GFCI protection. This includes automotive vacuum machines, drinking water coolers and bottle fill stations, cord-and-plug-connected high-pressure spray-washing machines, tire inflation machines, vending machines, sump pumps, and dishwashers.

Panelboards in bathrooms

Is it permitted to install panelboards in the bathrooms of commercial buildings? The designer located panelboards in the bathrooms of office tenant spaces because the owner did not want them in the hallway.

As currently written, Section 240.24(E) permits this installation. This requirement prohibits overcurrent devices (other than supplementary) in dwelling units, dormitory units, guest rooms and guest suite bathrooms. It is interesting to note that, during the first revision stage for the 2023 NEC , this section is modified to prohibit such an installation in any bathroom, showering facility or locker room with showering facilities.

Expansion fittings

An inspector flagged a conduit run and required expansion fittings because he saw a separation between the floor above and below the conduit run. Is that correct?

If the separation in the floor is a structural joint placed there to compensate for building expansion and contraction, then a listed expansion or deflection fitting is required. Section 300.4(H) addresses raceways that cross a structural joint intended for expansion, contraction or deflection and used in buildings, bridges, parking garages or other structures.

Neutrals and multiple circuits

I was told all neutrals in a 120/208V panelboard must be labeled or marked with circuit numbers. Is that right, and when did this become Code?

The requirement is in Section 200.4(B), Multiple Circuits. This applies where more than one neutral conductor associated with different circuits is in an any type of enclosure and is not limited to panelboards or any specific system voltage class. Where this occurs, grounded circuit conductors (neutrals) of each circuit must be identified or grouped to correspond with the ungrounded circuit conductor(s). This association can be achieved with wire markers, cable ties or similar means in at least one location within the enclosure.

Exception No. 1 provides significant clarity to the general requirement that the grounded conductors be identified or grouped in at least one location in the enclosure. Where branch circuits or feeder conductors enter an enclosure from a cable or raceway unique to that circuit, the grouping is obvious and no additional steps are necessary. The second exception excludes branch circuit conductors passing through a box or conduit body without loops, splices or terminations.