utility paralleling switchgear & Art. 700

[MIEngineer]

All,

I am researching utility paralleling switchgear for inclusion in possible future projects. I have "borrowed" a picture from a GE whitepaper on their equipment below. http://www.geindustrial.com/products/applications/tb2103.pdf Does this not violate Art. 700?

I have always designed so there are 2 breakers installed in the generator to feed two transfer switches located in the facility, 480/277. One for Art. 700 (egress lighting) and one for a larger Art. 702 (remaining general building loads) transfer switch.

If the utility and generator power is designed to tie together how is this separation obtained or allowed by code?

thanks for any responses.

 

[broadgage]

If the intention is to use the generator INSTEAD of the utility, perhaps in case of failure, then I believe that USA codes require a separete changeover contactor for egress lighting and general building load.

If however the intention is to use the utility supply AND the generator at the same time, perhaps to reduce peak load, then I dont see how such separetion can be achieved.
Both the egress lighting and the general load are normaly supplied from the same utility service which is acceptable. I dont believe that operating a generator in parralell with the grid would alter this.

One would of course have to satisfy the utility that parralell operation will be done safely, but that is a separete issue.

 

[steve66]

The thumbnail you show doesn't show any emergency loads. They are just using the generator to parallel utility and generator power for other loads. In this case, the emergency power might be battery packs (just as an example).

 

[MIEngineer]

The thumbnail you show doesn't show any emergency loads. They are just using the generator to parallel utility and generator power for other loads. In this case, the emergency power might be battery packs (just as an example).

Okay, the question I intended to ask but didn't. If I have emergency loads, no batteies, where do they belong in this scheme? Would I still need a second breaker in the generator?

I have seen this advertised but haven't found any actual implementation details.

 

[Smart $]

Okay, the question I intended to ask but didn't. If I have emergency loads, no batteies, where do they belong in this scheme? Would I still need a second breaker in the generator?

I have seen this advertised but haven't found any actual implementation details.

I believe the first place you will have to start for parallel power sources, is Article 705 Interconnected Electric Power Production Sources... and Part III specifically for generators... and go from there.