[RE-wrenches] 690.31E (was Request for Enphase comments)

Kelly Keilwitz, Whidbey Sun & Wind kelly at whidbeysunwind.com
Sun Oct 26 21:36:48 PDT 2008


Hi Ray,
I'm curious to know why you think that metallic conduit is required for the
inverter AC output. 690.31(E) specifically addresses DC source and output
circuits.

We have an AHJ who interprets the section the same as you and I've been
working to turn him (as he's now responsible for training other inspectors
on PV in our Region). Toward that goal I asked John Wiles for his input. He
said:

" The intent of 690.31(E) is to apply only to the always-energized DC
circuits and not to the ac output circuits from the inverter since they go
"dead" as soon as the circuit to the utility is opened at any point.
There was a typo in 690.31(E) in the 2008 NEC.  The word "of" should have
been "to" in front of the word "inverter".  The typo occurred in the
original submission (by me) to the Code Making Panel. The typo was not
detected during the review process.  The word "PV" modifies both "source"
and "output" .
The attached proposal is being submitted for the 2011 NEC that will make
corrections and expansions to 690.31(E)."

I'd be interested to know if other wrenches are being subject to the same
interpretation (i.e. inverter AC must be in metal).

-Kelly

Kelly Keilwitz, P.E.
Whidbey Sun & Wind, LLC
Renewable Energy Systems
NABCEP Certified PV Installer
987 Wanamaker Rd, 
Coupeville, WA 98239
PH & FAX 360-678-7131
sunwind at whidbeysunwind.com
On 10/24/08 10:31 AM, "R. Walters" <walters at taosnet.com> wrote:

> 
>  You run AC wiring right to the AC disconnect from the roof. You still have to
> comply with 690.31E, (steel conduit to the disconnect is required for both DC
> or inverter output to the first readily accessible disconnect)) but you only
> need a single AC disconnect. No combiner box, No accessible DC disconnect.
> 
> 
> Ray Walters
> 
> 


 






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