[RE-wrenches] transformerless inverters and conductor colors

[Kelly Larson]

Even though they say "Photovoltaic" in the spec sheet, I am not sure that this is "PV Wire".  I don't see anywhere that it actually uses those exact words, and that is the designation in the NEC.

Blessings,
Kelly



On Sep 27, 2013, at 10:38 AM, August Goers wrote:

> Marco,
>  
> Yes, there is single jacketed PV wire. I've attached a spec sheet for some 1000 V wire we've been using. I don't know anything about the actual wiring construction and why single versus double jacketing may or may not be used. I just know it needs to be listed for the purpose.
>  
> Best, August
>  
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Marco Mangelsdorf
> Sent: Friday, September 27, 2013 10:28 AM
> To: 'RE-wrenches'
> Subject: [RE-wrenches] transformerless inverters and conductor colors
>  
> Thanks, August.
>  
> OK, so I’ve found “PV wire” that’s double-insulated.  (See attached spec sheet from Falcon wire.)
>  
> Is there PV wire out there that’s just got a single insulation layer that qualifies as per what came from that helpful article below?
>  
> marco
> USE-2 is a standard wire designated for underground service entrance, typically used to connect terminals of a variety of service equipment. PV wire is specifically designated for use in PV module interconnections. Both cables are rated for 90oC wet or dry. PV wire, however, has thicker insulation to withstand the harsh environments frequently found in PV installations. USE-2 carries a 600V rating, whereas PV wire can be rated at 600V, 1000V or 2000V. There are separate ratings with increased insulation thickness for each cable.
> 
> Both USE-2 and PV wire can be used with grounded systems, but only PV wire may be used with ungrounded systems per NEC 2008. Since USE-2 has typically been installed underground or in environments where flame is unlikely, it usually does not require a flame retardant rating.The PV wire designation does include a VW-1 flame test requirement. Both ratings are sunlight resistant, but the PV wire rating applies a more stringent test requirement of 720 hours in weatherometer vs. 300 hour weatherometer test for USE-2.
> 
>  
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of August Goers
> Sent: Friday, September 27, 2013 4:18 AM
> To: RE-wrenches
> Subject: Re: [RE-wrenches] transformerless inverters and conductor colors
>  
> Marco,
>  
> My understanding is that PV wire is a separate listing. Exposed DC wiring with ungrounded non-isolated systems must be PV wire. USE-2 wire is not necessarily PV wire unless listed and labeled as PV wire. Here's a decent article:
>  
> http://www.renewableenergyworld.com/rea/news/article/2010/11/performancecost-trade-offs-in-pv-systems-wiringcabling-selection
>  
> Best, August
>  
> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Marco Mangelsdorf
> Sent: Friday, September 27, 2013 12:24 AM
> To: 'RE-wrenches'
> Subject: [RE-wrenches] transformerless inverters and conductor colors
>  
> Thanks, Glen.
>  
> This brings up the question of what exactly constitutes “PV Wire.”   “PV wire” does not necessarily = double-insulated wire which I thought is required with ungrounded PV systems on the DC side at least until you hit an enclosure and enclosed raceway where you can transition to THWN-2 wire.  Is there a clear and unambiguous definition out there of what constitutes “PV Wire”?  To some XLP/USE-2/RHW-2 wire is “PV Wire.”
>  
> marco
>  
> 2008 NEC
>  
> 690.35 Ungrounded Photovoltaic Power Systems.
> Photovoltaic power systems shall be permitted to operate with ungrounded photovoltaic source and output circuits where the system complies with 690.35(A) through (G).
> (A) Disconnects.
> (B) Overcurrent Protection.
> (C) Ground-Fault Protection.
> (D)  The photovoltaic source conductors shall consist of the following:  
> (1)          Nonmetallic jacketed multiconductor cables 
> (2)          Conductors installed in raceways, or 
> (3)          Conductors listed and identified as Photovoltaic (PV) Wire installed as exposed, single conductors.
>  
> Raceway.  An enclosed channel of metal or nonmetallic materials designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this Code. Raceways include, but are not limited to, rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight flexible conduit, flexible metallic tubing, flexible metal conduit, electrical nonmetallic tubing, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.
>  
> Reads to me like you can transition to THWN-2 inside a rooftop jbox from the PV wire under the modules, as long as it is in a raceway.
>  
> -Glenn Burt
> <EncoreWire-Photovoltaic (2).pdf>_______________________________________________
> List sponsored by Home Power magazine
> 
> List Address: RE-wrenches at lists.re-wrenches.org
> 
> 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
> 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org/attachments/20130927/986685bf/attachment-0003.html>