Medium Voltage Throwover Breaker Scheme - Article 700 Compliant?

[cvirgil467]

Anyone know how to rationalize how using electronically operated circuit breakers as a throwover scheme to meet NEC Article 700? This is in regards to complying with NFPA 130 for emergency ventilation fans.

Attached one line for reference.

Thanks.
c

 

[charlie b]

I think they are OK, as long as the Article 700 loads get power within 10 seconds of loss of normal utility power.

My question is whether you need to take credit for the generators, given three utility feeds. Are the three sufficiently reliable and independent to satisfy Article 700?

 

[cvirgil467]

Thanks Charlie.

The (3) feeders do have a single point of failure along their route to the site. Client wanted generators to sleep at night.

I'm struggling to rationalize how this setup can also serve 701 and 702 loads. We can setup the board where we have separate 700, 701, and 702 sections and even load shed off the 702 loads as needed. But its effectively only one transfer switch and 700.5(c) (NEC 2020) is clear - transfer equipment shall only supply emergency loads.

I might have to identify the 701 loads as 700 loads and load shed off the 702 loads when the generator kick in.