Separately derived systems

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Vernondeville

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overseas on military instalation
I work overseas. I have an AIR FORCE Maintenance tent which has 2 separate panels one on each side of the tent.
They are not interconnected 1 panel services one side of the tent. The other panel the other side of the tent.

My question is; is it against NEC to have 2 separate generators one on each panel feeding the same structure?
 
Vernondeville said:
No, everything over here has to be done according to current code

Thank you for the code reference
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I see them as feeders because each genny has an OCPD.

For me one could called the main feeder and the other could be one of the applicable exceptions.

Still hard to apply the NEC to a tent and a federal one no less, but if that what is the DoD wants in this scenario....
 
jumper said:
Why is this US military structure under the NEC, usually feds have their own rules?
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The governing documents for design of military buildings are the Unified Facility Criteria (UFCs). Paragraph 1-5 of UFC 3-520-01, "Interior Electrical Systems," states, "Comply with the requirements of National Fire Protection Association (NFPA) 70, National Electrical Code, and the requirements herein."
 
charlie b said:
The governing documents for design of military buildings are the Unified Facility Criteria (UFCs). Paragraph 1-5 of UFC 3-520-01, "Interior Electrical Systems," states, "Comply with the requirements of National Fire Protection Association (NFPA) 70, National Electrical Code, and the requirements herein."
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It is definitely a structure but a building? OP said it was a tent.

If DoD says it’s a building, than I guess it is for them.
 
This is a bit tricky. 224.30(A)(4) appears to assume that there is a utility as the normal source, and that the generator is an optional standby source. In this instance, each generator is the only source to the panel on its side of the tent. It is not optional standby; it is not even "standby." I think your best bet is to apply 225.30(E). The Air Force maintenance crews would almost certainly have documented switching procedures.
 
jumper said:
It is definitely a structure but a building? OP said it was a tent.
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I originally wanted to say "design of military facilities." I used the term "building" instead in order to avoid using the words "facilities" and "facility" too close to each other.

 
charlie b said:
This is a bit tricky. 224.30(A)(4) appears to assume that there is a utility as the normal source, and that the generator is an optional standby source. In this instance, each generator is the only source to the panel on its side of the tent. It is not optional standby; it is not even "standby." I think your best bet is to apply 225.30(E). The Air Force maintenance crews would almost certainly have documented switching procedures.
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I could agree to that also.

Regardless of which one we pick, I see no problem or safety issues.
 
I think 225.30(B)(2) could apply. As the power source is generators, it is easy to justify that the structure and its power demands are large enough to require two services.
 
Craigv said:
I think 225.30(B)(2) could apply. As the power source is generators, it is easy to justify that the structure and its power demands are large enough to require two services.
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Please consider it to be two feeders in the case of generators, since service by definition requires a utility as the source.
 
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