Tow-behind Generator Question

busman

Senior Member
Location
Northern Virginia
Occupation
Master Electrician / Electrical Engineer
I need to connect a tow-behind leased generator to a temporary shelter for research purposes. It is 208/120Y. I could not get 5-conductor Type W cable quickly enough. I have 4-conductor. Any Code issues with the three hots and the neutral in the 4-conductor cable and a separate properly sized EGC run separately? I would strap the two together. It "feels" OK since these temporary installs are frequently done with a bunch of single conductor cables. I will post signage indicating that the EGC must be "first connect / last disconnect". Thoughts?

As always, thanks. Got this one on a short fuse and don't have days to spend trolling the NEC for answers.

Mark
 
How big is this generator? The rental companies usually have banded sets of 2g and individual strands of 2/0 and 4/0; any of those ought to work.

(FWIW, I hardly ever use multi-conductor larger than 6/4 for temp power setups, and that's always single phase. Anything bigger is single strands.)

Oh, and you didn't ask, but....
IMHO you don't need a grounding electrode at the generator, but you may at the structure/shelter if it's more than a tent. (There have been many discussions about this on these forums.)
 

busman

Senior Member
Location
Northern Virginia
Occupation
Master Electrician / Electrical Engineer
How big is this generator? The rental companies usually have banded sets of 2g and individual strands of 2/0 and 4/0; any of those ought to work.

(FWIW, I hardly ever use multi-conductor larger than 6/4 for temp power setups, and that's always single phase. Anything bigger is single strands.)

Oh, and you didn't ask, but....
IMHO you don't need a grounding electrode at the generator, but you may at the structure/shelter if it's more than a tent. (There have been many discussions about this on these forums.)
50 KVA. They didn't rent any cables from the company. It probably should have a GE, but its on the beach. Hard to do effectively in the sand. More concerned with Lightning Protection.

Thanks,

Mark
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I need to connect a tow-behind leased generator to a temporary shelter for research purposes. It is 208/120Y. I could not get 5-conductor Type W cable quickly enough. I have 4-conductor. Any Code issues with the three hots and the neutral in the 4-conductor cable and a separate properly sized EGC run separately? I would strap the two together. It "feels" OK since these temporary installs are frequently done with a bunch of single conductor cables. I will post signage indicating that the EGC must be "first connect / last disconnect". Thoughts?

As always, thanks. Got this one on a short fuse and don't have days to spend trolling the NEC for answers.

Mark
300.3(B)(3) would permit that installation.
 
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