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Re: Question [Re: HotLine1] #208543 01/27/13 10:54 AM
Joined: Jun 2004
Posts: 610
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shortcircuit Offline
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Hotline...there was a fire on a roof in Bakersfield California similar to what you are showing. The cause of that fire was determined to be a groundfault. Here is a link to info on that fire...

http://nfpa.typepad.com/files/target-fire-report-09apr29.pdf

Add here is a good article by Bill Brooks...

http://www.solarabcs.org/about/publications/reports/blindspot/pdfs/BlindSpot.pdf

Your fire should be documented for the solar industry.

Where, when, and what do you know about this fire?

shortcircuit

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Re: Question [Re: HotLine1] #208544 01/27/13 10:58 AM
Joined: Jun 2004
Posts: 610
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shortcircuit Offline
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Originally Posted by HotLine1
Greg:
This is the combiner box closest to the assumed point of origin of the fire. No definitive cause or location was available as of this afternoon.

[Linked Image]


That appears to be a nonmetalic combiner box with EMT. Were bonding jumpers installed?

shortcircuit

Re: Question [Re: shortcircuit] #208546 01/27/13 01:35 PM
Joined: Apr 2004
Posts: 810
Theelectrikid Offline
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Originally Posted by shortcircuit
That appears to be a nonmetalic combiner box with EMT. Were bonding jumpers installed?

shortcircuit


Looks like PVC to me, I see the barcode on the bottom-most conduit.


Is there anyone on board who knows how to fly a plane?
Re: Question [Re: HotLine1] #208548 01/27/13 01:47 PM
Joined: Feb 2002
Posts: 2,233
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harold endean Offline
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John,

Yes please keep us informed. I would like to see the outcome of this problem was. I am still on the fence about the safety of this things.

I know I would prefer the PV systems that have the mini inverter on each PV panel. This way the DC current stops right there on the roof.

Re: Question [Re: HotLine1] #208561 01/29/13 09:03 PM
Joined: Apr 2002
Posts: 7,121
HotLine1 Online Content OP
Member
Shortcircuit:
Thanks for the links!!! Appreciate it!!!

Combiner boxes are metalic, 3R, etc. conduit is PVC with grd conductor.

Documentation is being compiled on my end.


John
Re: Question [Re: HotLine1] #208565 01/29/13 10:27 PM
Joined: Apr 2002
Posts: 7,121
HotLine1 Online Content OP
Member
Here is another angle pic.
[Linked Image]


John
Re: Question [Re: HotLine1] #208633 02/03/13 01:15 PM
Joined: Jun 2004
Posts: 610
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shortcircuit Offline
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That looks like a Solectria combiner box.

Re: Question [Re: HotLine1] #208639 02/03/13 02:23 PM
Joined: Apr 2002
Posts: 7,121
HotLine1 Online Content OP
Member
As of Fri. there has been no root cause determined. The area of the roof has been set into a grid, the remains being tagged and boxed and removed from the roof. The remains will be reviewed further to see if a cause can be determined.


John
Re: Question [Re: HotLine1] #208644 02/03/13 09:08 PM
Joined: Jul 2004
Posts: 9,409
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gfretwell Online Content
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Assuming a number of the collector pans look like this.

I guess the first question I have is what happens to those collectors if they feed a bolted fault. Is there collector level over current protection?
You might be looking at a symptom there and you had a bigger problem on the load side.



Greg Fretwell
Re: Question [Re: HotLine1] #208652 02/04/13 12:27 AM
Joined: Apr 2002
Posts: 7,121
HotLine1 Online Content OP
Member
Greg:
The combiner boxes like these are 16 circuit, finger safe fuses (midget). I'll venture a guess at 100K minimum for the fuses.
I'll get the rest of the specs tommorrow.


John
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