690.35(D) does *not* require PV WIRE be used for the whole dc circuit.
You can use either: (quoting directly from 2008)
1) Nonmetallic jacketed multiconductor cables
2) Conductors installed in raceways, or
3) Conductors listed and identified as PV WIRE installed as exposed,
single conductors
Similarly, I don't believe that the NEC requires red and black color
coding, either, though it makes the most sense given convention.
Note Brian Teitelbaum's 6/3 email about PV WIRE noting that
"double-insulated" is a bit of a misnomer. Some PV WIRE is single-insulated.
DKC
On 2013/6/28 13:47, [email protected] wrote:
In ungrounded systems the PV wire requirement is to be used the whole
DC circuit, so that is all the way to the inverter. 690.35 (D) is
pretty clear . Because it is ungrounded the protection is the PV
wire's fire rating and you don't get that with thhn/thwn.
And of course Red for positive and black for negative.
Most building departments have not pick up on this yet. But they will.
Aram
-------- Original Message --------
Subject: Re: [RE-wrenches] double insulated wire
From: Will White <[email protected]
<mailto:[email protected]>>
Date: Fri, June 28, 2013 10:23 am
To: RE-wrenches <[email protected]
<mailto:[email protected]>>
We use PV Wire which is double insulated on the roof in free air
and regular THHN/TNWN for the run from the junction box back to
the inverter (using no white or gray wires of course).
Thanks,
Will
____________________________________________________________________________________________
Will White
Regional Field Operations Manager -- New England
Real Goods Solar
64 Main St.
Montpelier, VT 05602
Tel: (802) 223-7804
Cell: (802) 234-3167
www.realgoodssolar.com <http://www.realgoodssolar.com/>
*From:*[email protected]
<mailto:[email protected]>
[mailto:[email protected]] *On Behalf Of
*Marco Mangelsdorf
*Sent:* Friday, June 28, 2013 1:10 PM
*To:* 'RE-wrenches'
*Subject:* [RE-wrenches] double insulated wire
I'm kinda confused. With more transformerless inverters on the
market (e.g., SMA and Power-One), it's not clear to me if double
insulated wiring needs to be used all the way from each series
string to their respective inverter.
We've been installing the P1 3-6 kW TL inverters and there's no
apparent mention of needing to use such conductors, yet I remember
needing to do so when I installed a number of the 8, 9 and 10 kW
SMA TL inverters.
Thanks,
marco
------------------------------------------------------------------------
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
<mailto:[email protected]>
Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive:
http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
<http://www.re-wrenches.org/etiquette.htm>
Check out participant bios:
www.members.re-wrenches.org <http://www.members.re-wrenches.org>
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
_______________________________________________
List sponsored by Home Power magazine
List Address: [email protected]
Change email address & settings:
http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org
List rules & etiquette:
www.re-wrenches.org/etiquette.htm
Check out participant bios:
www.members.re-wrenches.org
