PSPV mounting PSPV on roof, PSPV wiring, 150 Volt

Discussion about the Power System PV Combiner (PSPV)

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DEveland
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Location: Philomath, OR and San Diego, CA
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PSPV mounting PSPV on roof, PSPV wiring, 150 Volt

Post by DEveland » Wed Aug 11, 2004 9:19 pm

Explore for ideas for a good looking clean wiring and mounting job for a roof mounted PSPV. For an application on a 3:12 (14 deg) roof.

I am contemplating mounting the PSPV under the solar array for a cleaner look. This may not be appropriate since it makes the breakers inaccessible; however, since they are not the primary circuit protection maybe it's OK. What do you think? Also, will this make the breakers too hot?

Also, the array is wired with USE-2 cables, obviously one "+" and one "-" per string; I have 8 strings, so 16 wires. I'm looking for ideas on how folks are doing clean and reliable wiring and conduit jobs when you have so many wires to get into the combiners. I've used Bell boxes to gather the wires into one or two conduits, but this sometimes gets costly and cumbersome. Any ideas for other weathertite boxes that are thin enough to fit under the array, but that have enough length and volume to combine more circuits with fewer boxes. Also, I've used 2-wire cord grips directly into combiners. What are you doing and what ideas do you have. I prefer to hide all wiring/conduits under the array.

A question for the mediator/administrator. I called in and was told the OBDC breakers have been re-rated to 150 VDC. Is this true and do you have any documentation I can have in case of questions from customers or inspectors?

Thank You All

Christopher

Re: PSPV mounting PSPV on roof, PSPV wiring, 150 Volt

Post by Christopher » Thu Aug 12, 2004 11:33 am

DEveland wrote: A question for the mediator/administrator. I called in and was told the OBDC breakers have been re-rated to 150 VDC. Is this true and do you have any documentation I can have in case of questions from customers or inspectors?
Yes - the OBPV series of breakers have an additional approval for use with PV arrays up to 150 vdc of open circuit voltage. This approval is in addition to the 120 and 80 vdc approvals already marked on the breakers.

We will be posting the approval letter on the website in the near future - or give a call if you need it sooner with a fax number and we can send it to you.

Christopher 8)

Christopher

Re: PSPV mounting PSPV on roof, PSPV wiring, 150 Volt

Post by Christopher » Thu Aug 12, 2004 11:42 am

DEveland wrote:Explore for ideas for a good looking clean wiring and mounting job for a roof mounted PSPV. For an application on a 3:12 (14 deg) roof.
The PSPV is approved for slanted mounting on a roof as low as 3:12 pitch - so your covered there. Putting it behind the modules is a little bit gray - access to the customer is not required (its considered as "supplementary protection") but it should be serviceable. I think if the mounting system and wiring allows reasonable lifting / tilting of the panels without disrupting the wiring it my go through - just call the modules a protective covering for the combiner box :shock:

The OBPV breakers are hydraulic-magnetic type - so the high ambient will not affect their trip levels (but will reduce their time delays). The real issue is the temperature itself and the wire and terminals ratings - it might get over 75C behind there??? :?

I think using the 2-wire cord grips directly into the PSPV combiners is the cleanest and cheapest overall solution - especially if the PSPV is behind the modules.

Christopher 8)

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