Generator for Commercial Bldg - code/requirements

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Dark Sparky

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Electrical Engineer
We're designing an auto dealership in FL. Owner wants to add generator for "some" loads. Does not want to segregate loads (no Emerg vs. Normal panels). Rather, they plan to manually turn on/off breakers when running on generator. This will be a connection for a rollup generator, not a permanent gen.

1) What general codes govern this?
2) Does having the generator connection mandate supplying certain loads (fire alarm, emergency lighting, etc.) from the generator? If so, ideas on how to implement this, given that the loads won't be segregated into normal vs. emergency? I can accept adding an emergency panel for this purpose if it's code-required.
3) Anything else high-level that I should consider/implement with this design?

Thanks!
 
please review the scope of article 700, 701 and 702.
You have a Art 702 system. Calling this an emergency generator will cause a lot of confusion on permits.
You will need to know if the generator neutral is bonded or not, that will determine the type of transfer switch and inlet labeling signage.
 
please review the scope of article 700, 701 and 702.
You have a Art 702 system. Calling this an emergency generator will cause a lot of confusion on permits.
You will need to know if the generator neutral is bonded or not, that will determine the type of transfer switch and inlet labeling signage.

Thanks, Tom, that's useful. I am familiar with neutral bonding for permanent gens. In this case, given that it will be a portable generator of unknown sourcing, is there a way to know if the neutral would typically be bonded?
 
You have a couple options:

You can supply a bonded neutral genny, and install transfer equipment for an SDS.

You can supply a floating neutral genny and install “standard“ transfer equipment.

You can float the neutral on bonded neutral genny, and install transfer equipment for a non-SDS.

But whatever transfer system you install, per NEC it must now be labeled for what system it’s designed for.
 
I vote for setting it up with transfer gear for SDS for bonded neutral gennie. Its alot easier to throw a camlock T in the mix to bond the neutral at the gennie in the rare instance you end up with one that doesnt have N-G bond than it is to remove an unwanted N-G bond inside the generator.
 

Trystar and PSI make some nice 'generator dock' camlock panels. Regardless of vendor, I advise to have them made with a phase monitoring relay tied to indicator lights and unvervoltage release on the breaker so you can't energize the building if phase rotation is backwards.
 
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