[RE-wrenches] RE-wrenches Digest, Vol 6, Issue 423

Tue Nov 12 08:51:33 PST 2013

Hi Bill –

If there is a short circuit between two conductors or to ground under the
DC array won’t the fire issue still remain? I understand the arc fault will
stop load from the inverter side but it seems like it does not entirely
solve the problem. Or maybe I’m not fully understanding how AFCI works.

I was on the roof the other day inspecting a 10 year old system installed
right on the coast. The inverter was dead and probably had been dead for
several years. On the roof the DC combiner box had rusted out (NEMA-3
installed at 5:12 pitch!) and there had been a pretty serious fire in the
box. Luckily it didn’t spread to the roof – it was still arcing away when I
busted open the rusted lid. That seems like a workmanship the materials
selection issue to me.

Best,

August

August Goers

Luminalt Energy Corporation

o: 415.641.4000

m: 415.559.1525

www.luminalt.com

*From:* re-wrenches-bounces at lists.re-wrenches.org [mailto:
re-wrenches-bounces at lists.re-wrenches.org] *On Behalf Of *Bill Brooks
*Sent:* Monday, November 11, 2013 3:38 PM
*To:* 'RE-wrenches'
*Subject:* Re: [RE-wrenches] RE-wrenches Digest, Vol 6, Issue 423

William and David,

This particular problem goes away with arc fault detection. The longer we
wait to introduce arc fault detection into our systems, the more we will
have opportunities for news reports such as the one William brings forward.
Wire ties are not the problem. Could a wire tie cause a problem-sure, just
like anything improperly installed.

At the end of the day, you can a have a perfectly installed system, but if
it does not have arc fault detection and high resolution ground fault
detection, it can still catch on fire. You have no control over product
failures other than buying from large companies that can actually insure
their products in a failure.

Fires are not that common, but it didn’t take much to get all the viewers
of this news report up in arms did it?

Bill.

*From:* re-wrenches-bounces at lists.re-wrenches.org [
mailto:re-wrenches-bounces at lists.re-wrenches.org<re-wrenches-bounces at lists.re-wrenches.org>]
*On Behalf Of *David Brearley
*Sent:* Monday, November 11, 2013 11:37 AM
*To:* RE-wrenches
*Subject:* Re: [RE-wrenches] RE-wrenches Digest, Vol 6, Issue 423

William,

Thanks for posting a link to that story.

Here's more background on the tile roof integrated PV system recall and
warranty fiasco:

http://runonsun.com/~runons5/blogs/blog1.php/solworks/safety/suntech-recalls-solar-roofing-tiles

http://runonsun.com/~runons5/blogs/blog1.php/ranting/centex-clouds-solar-tile-repairs

http://runonsun.com/~runons5/blogs/blog1.php/solworks/safety/centex-suspends-solar-repairs

http://runonsun.com/~runons5/blogs/blog1.php/solnews/centex-steps-up-will-replace

It sounds like this could be a product design failure rather than a wire
management issue. But wire management is certainly suspect until proven
innocent. Regardless of the cause, since these are roof integrated systems,
Centex basically needs to replace all of the TIPV systems with conventional
rack-mounted PV systems—provided they can get the homeowners to sign the
liability releases.

Even though these are relatively unique installations, the general lessons
would seem to apply broadly. Qualify your vendors carefully. Make sure your
installers are properly trained. Put QC systems in place to catch problems.
A small investment in quality wire management practices is cheap compared
to the alternative.

Best regards,

David Brearley

Senior Technical Editor, *SolarPro* magazine

On Nov 11, 2013, at 1:02 PM, re-wrenches-request at lists.re-wrenches.orgwrote:

*From: *"William Miller" <william at millersolar.com>

*Subject: [RE-wrenches] House fire news*

*Date: *November 11, 2013 12:09:08 PM CST

*To: *"RE-wrenches" <re-wrenches at lists.re-wrenches.org>

*Reply-To: *RE-wrenches <re-wrenches at lists.re-wrenches.org>

Friends:

This was brought to my attention:
http://on.aol.com/video/are-solar-panels-a-fire-hazard--518000682?hp=1&playlist=127173&icid=maing-grid7%7Cmain5%7Cdl12%7Csec1_lnk3%26pLid%3D403848

I know this is an isolated scenario, but bad PR can spread like umm,
wildfire.  We should all be aware of bad press so we can respond to
questions about safety hazards.

I think this story is relevant in that as the number of PV installations
continues to grow, the chance of an accident naturally increases. I believe
we all need to do the best work possible to minimize this risk.  Even
though some of the Code requirements seem illogical, I favor strict
adherence to the code, including the more subjective judgments on good
workmanship.

I look forward to the day when plastic wire ties of any type are not
accepted for wire management – I think they are sub-standard practice and
increase the likelihood of fire or shock hazards.

William Miller

<image003.jpg>

17395 Oak Rd. Atascadero, CA 93422

www.millersolar.com

805-438-5600 voice
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