Hi Wrenchers,
 
I recently butted heads with an old school electrician who has been 
scrutinizing a recent install (fully permitted & PTO'd last year) and I wonder 
how applicable and valid his concerns are. I'm not interested in an ego war 
with this guy; I just want to be code-compliant and safe. This sparky (let's 
call him Karl) has questioned my electrician's (let's call him Dave) use of NM 
cable on the AC side of the solar install.
 
The first issue that Karl raised was that Dave installed Romex for our 
supply-side connection, i.e., from our fused disconnect to the Polaris vampire 
clamps on the feeder conductors between the meter and the main disco. Karl 
contends that the Romex, by extension off of the utility feeders, is now a 
service entrance conductor and that NEC Article 334.12 dictates that Romex 
cannot be used as service entrance conductors. Wondering how you all might 
interpret this scenario. (note: We have the opportunity to pull new conductors, 
should the consensus be that we violated the NEC)
 
The second issue is that Dave ran 6AWG Romex from the fused disconnect to the 
main breaker in the combining subpanel and landed the circuit on a 70A breaker. 
The inverter circuit is rated at max current of 50A continuous. Karl is telling 
us that the #6 Romex is rated at 60 degrees and 55 amps. It is my understanding 
that all NM cable is now rated at 90 degrees. However, I also understand that 
there may be some merit to Karl's assessment regarding limited ampacity of the 
6AWG Romex. Can someone illuminate this issue for me as to whether or not NM 
cable is rated at 90 degrees AND therefore a 6AWG conductor in NM cable would 
have a 75A rating?
 
Cheers,
 
Eric
SunHarvest
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