2017 NEC 700.10 (B) (5) Wiring - Generator Output Circuit Breakers

[Troy K]

Does this code section prohibit two circuit breakers in the output cabinet of a generator, one serving a transfer switch serving emergency (NEC 700) loads and one serving a transfer switch serving optional standby (NEC 702)loads? The breakers are not installed in separate enclosures and the wiring is not separated until it enters the conduit from the generator to the transfer switch.

 

[mparenteau]

In my opinion, there is no prohibition.

Mike

 

[Troy K]

Thanks for sharing mparenteau. I appreciate your input. I did talk with NFPA on the phone after my post and the person I talked with said there is some code text proposed for the 2023 NFPA 700.10 to clarify the intent.

Troy

 

[resqcapt19]

Here is the proposed 2023 text.

At the emergency power source, such as a generator, multiple integral overcurrent protective devices shall each be permitted to supply a designated emergency or a designated nonemergency load, provided that there is complete separation between emergency and nonemergency loads beginning immediately after the overcurrent protective device line-side connections.