[RE-wrenches] EMT in attic

[Dave Click]

Nick, what the AHJ is telling you may actually be in reference to 
250.97; for most PV output circuits (yes these are necessarily dc) this 
bonding requirement applies since array VOC > 250 VDC. As Kent just 
pointed out, these dc conductors clearly don't meet the NEC definition 
of a service.

"250.97 Bonding for Over 250 Volts. For circuits of over 250 volts to 
ground, the electrical continuity of metal raceways and cables with 
metal sheaths that contain any conductor other than service conductors 
shall be ensured by one or more of the methods specified for services in 
250.92(B), except for (B)(1)..." followed by an exception.

Seems that FMC is OK as an EGC if your conductors have <20A OCPDs, which 
I imagine you do, but that FMC also can't be longer than 6' (see 
250.118(5)). So I think your AHJ is probably right and I just learned 
something. If you're running a separate EGC anyway, you may want to ask 
why this bonding business is so important-- but I don't have an NEC 
reference on this to help you argue this. Maybe the AHJ would allow you 
to just run MC cable as the 2011 NEC allows.

John Wiles is awesome. Someone on this list had to say it.

DKC

On 2012/11/8 23:22, Nick Vida wrote:
> Hi Wrenches,
>
> Thanks for you comments. Fun for the day is hearing they want to apply
> section 230 about service conductors and say that flex is not
> a metallic raceway because it is no good for bonding. They are defining
> the pv source circuits as a service.
> I am getting a distinct Wiles vibe here.
>
> I find it so annoying when they try to put out these distinctions with
> no code, no city ordinance and not even an internal memo, especially
> when they remain obstinate without going to the trouble to actually
> legitimize the interpretation.
>
> Dan- are the output circuits necessarily DC? I would have to look at NEC
> for a minute, but it doesn't seem to add up to me right now.
>
> Thanks,
>
> Nick Vida
>
>
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