Compliant Backup Generator Circuit?

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tryinghard

tryinghard

Senior Member
Location
California
Scenario: normal utility power also includes a kirk key transfer for a vehicle type portable generator to be plugged in when needed and the circuits include the following.

Service disconnect 100A breaker, #2s to subpanel main 100A breaker, and a periodic generator with 3ph 100A breaker (OCPD) connected to #6 SO cord, 50A cap & plug, #6s to subpanel with 45A backfed breaker kirk keyed with 100A main. I am not questioning the kirk key arrangement with lower main but do question the #6 cord, cap & recept, and #6 feeder from the generator’s 100A apparently using the downstream 45A protection – is this scenario compliant?
 
Can't see how would be, it's certainly not good practice. How long is this SO cable (tap rules)? Is it lugged onto the genset bus bars or onto a connector (which should already have proper OCPD)?

Without other info, I don't think this fits any of the (few) options where you can protect conductors at the far end from the source, and I certainly wouldn't try going down that road. If nothing else, an A/C disconnect box with a 60a breaker is under $100...
 
not a tap rule issue, the cord is around 50' and the #6 feeder another 50'. The electrician believes it has protection from the downstream 45A breaker.
 
tryinghard said:
The electrician believes it has protection from the downstream 45A breaker.
Click to expand...

He can believe that, and it'll probably work, but--

240.21 Location in Circuit. Overcurrent protection shall be provided in each ungrounded circuit conductor and shall be located at the point where the conductors receive their supply except as specified in 240.21(A) through (H).

I suppose he could try to hang his hat on 240.21(B)(5), but I wouldn't.
 
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