Code Guide

Q: The Code reference in question specifies one (1) 20A circuit for bathroom receptacles. We are seeing modular homes with more than one bathroom connected on one circuit. It is my interpretation that only one bathroom is allowed on a circuit. Does the Code say one bathroom per circuit?

A: The main rule of Section 210-11(c)(3) requires a 20A circuit that is dedicated to bathroom receptacle outlets. It does not require a separate circuit for each bathroom. One circuit may supply multiple bathrooms as long as only bathroom receptacles are supplied. Lighting outlets or receptacle outlets in other rooms may not be supplied by this circuit.

However, an exception was added to the 1999 Code that permits a circuit that is dedicated to a single bathroom to supply other outlets such as a lighting outlet or a fan. In order to use this exception, an additional circuit or circuits must be provided for any additional bathrooms. Since Section 210-23(a) applies to this circuit, any single additional loads that are fastened in place (such as a fan) are limited to 10A.

Q: My question pertains to an installation in Fairfax County, Va. that still follows the 1996 NEC. We have a project where the main electrical service is located in the same room as the controller/disconnect for a fire pump. The fire pump controller is located 6 feet from the main service switchboard, and is fed by dual sources, the normal power and an emergency generator.

Is the 6-foot physical spacing acceptable and does it need to be in a separate room, or can it be in a separate space? Can the controller be located in an area behind a 6-foot block wall that is open on top, so that it is still part of the same electrical room?

The 1996 NFPA Handbook for the NEC shows an illustration of a generator dedicated to the fire pump. It describes a direct connection in Section 695-4(b). Is this the intent of the Code? We typically will design a generator service, by bringing the emergency feeder into a distribution panelboard and feed sub-feeders from that panelboard to various emergency loads through automatic transfer switches, such as elevators, egress lighting and the fire pumps. We typically will size the fire pump emergency service to be at 250% of the full load requirements of the pump motor. Is that also within Code?

Does the direct connect requirement of the Code really necessitate a dedicated emergency generator service to the fire pump?

A: As noted in the commentary of the 1996 NEC Handbook, neither the NEC nor NFPA 20 require a dedicated room. NFPA 20 does describe a suitable space. Certainly it can be in the same room, perhaps separated by a partition or barrier, but even a barrier is not necessarily required. There must be sufficient separation to minimize the possibility that some accident in the normal service will also compromise the fire pump installation. The AHJ should be consulted in individual cases.

The NEC requires a reliable source of power for a fire pump.

In some jurisdictions, the utility source may be judged to meet this requirement. However, in many situations, an on-site source is also required. A generator used to supply a fire pump need not be dedicated to the fire pump, but the direct connection requirement you refer to (Section 695-4(b) in the 1996 NEC) would require a separate transfer switch for the fire pump, usually as part of a listed combination fire pump controller and transfer switch. This usually also requires a separate feeder, perhaps separately routed, from the generator to the fire pump transfer switch.

Your 250% rule may or may not provide adequate capacity for the fire pump. The capacity of the feeder conductors is only required to meet the normal 125% requirement for motors in general. However, the overcurrent device should be selected to provide short-circuit and ground-fault protection only and the controller is not permitted to provide overload protection.

The overcurrent device must allow the locked-rotor current to continue indefinitely. This is better covered in the 1999 NEC. However, users of either the 1996 or 1999 NEC should also refer to NFPA 20, Standard for Installation of Centrifugal Fire Pumps. See Appendix A for specific references to NFPA 20 that are extracted and included in the NEC.

Q: The National Electric Code mandates the use of GFCIs in high-risk areas of all new residences. Do you have any statistics regarding how many U.S. houses were built prior to the NEC mandate that are without GFCI protection? If you have this information could you also please tell me the source? Or can you give me some suggestions on whom I may contact to get this info?

A: I do not know of any source for the information you are looking for. I suspect that such information would be very difficult to compile. Over the years GFCI requirements have been expanded in most three-year code revisions.

In addition, some older homes have been upgraded but not all of these were brought up to current Code requirements. Some, such as mine, even exceed NEC requirements and have GFCI protection on receptacles that are not required to be GFCI protected. Another factor is that some homeowners do not understand GFCI protection and consider it to be an unneeded bother. In some homes the GFCIs have been removed and replaced with standard devices.