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Thread: Burned out fuses

  1. #31
    Join Date
    May 2011
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    4,693
    Quote Originally Posted by solar.stevepvip View Post
    Do you have any recommendations on rack mounting a pvc box on ironridge rails?

    Sent from my SM-G955U using Tapatalk
    Bolt it to a couple ironridge L-feet. I'll admit his doesn't allow for the j-box to be under the panels on flush mount systems, if that's important to you.

  2. #32
    Join Date
    Jan 2012
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    CA
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    Quote Originally Posted by gadfly56 View Post
    If you're really curious and this is a regular customer, see my post at #9 for your solution.
    just ordered

  3. #33
    Join Date
    Sep 2016
    Location
    Missouri
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    35
    Quote Originally Posted by Zee View Post
    I do wonder what the record temp was in the J Box....
    NEC 690.7(A) note, look up ASHRAE Temperature tables for US cities. There are columns that match temperatures with distances in conduit. In my area a conduit 0" to 0.5", the temp is 156F, then from 0.5" to 3.5" is 134F and so forth. A soladeck being directly on the roof may exceed rated designs for devices involved, fuses, wire, etc. It blows my mind when you design an array how many precautions need to be taken when the array is there for 25+ years.

  4. #34
    Join Date
    Oct 2007
    Location
    New Jersey
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    6,201
    Quote Originally Posted by Ozymandias View Post
    NEC 690.7(A) note, look up ASHRAE Temperature tables for US cities. There are columns that match temperatures with distances in conduit. In my area a conduit 0" to 0.5", the temp is 156F, then from 0.5" to 3.5" is 134F and so forth. A soladeck being directly on the roof may exceed rated designs for devices involved, fuses, wire, etc. It blows my mind when you design an array how many precautions need to be taken when the array is there for 25+ years.
    Or, he can do as I suggested at #9 and and #30 and find out for sure, no guess-work involved.

  5. #35
    Join Date
    Sep 2016
    Location
    Missouri
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    35
    Quote Originally Posted by gadfly56 View Post
    Or, he can do as I suggested at #9 and and #30 and find out for sure, no guess-work involved.
    Absolutely, I just suggested a guideline but individual conditions determine it. That temp gage looks very handy.

  6. #36
    Join Date
    Jan 2012
    Location
    CA
    Posts
    527
    Built a sheet metal simple shade cover to cool it a bit. Painted it white.
    Did sophisticated touch test of white metal vs black solar panel. Less hot.
    Gutted fuses and used black polaris connectors.

    Oh.....Customer paid $1000 to utility last year due to loss of half his system...wants me to pay him!
    Snap!

    Now I wonder how many of these fused systems I have...and how many have problems...how many will.
    Well better to catch it now. Chalk it up to a learning experience.

    To sum it up:
    Seems issues really arise when
    fuses are on roof,
    CB is in full sun,
    especially if soladeck,
    darker color

    Does anyone think #12 would heat up more than #10 wire? 9 amps pv. To a degree that contributed to failure of fuse.
    Last edited by Zee; 08-04-18 at 04:48 PM.

  7. #37
    Join Date
    Nov 2015
    Location
    CA, USA
    Posts
    681
    Quote Originally Posted by Zee View Post

    Oh.....Customer paid $1000 to utility last year due to loss of half his system...wants me to pay him!

    I don't generally have anything to do with residential work so I don't know this but is it normal in a residential PV installation to not have anyone notice there is a problem until the annual true-up shows up and the customer owes a bunch of money? Is the monitoring just ignored all those months?

  8. #38
    Join Date
    Oct 2007
    Location
    New Jersey
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    6,201
    Quote Originally Posted by pv_n00b View Post
    I don't generally have anything to do with residential work so I don't know this but is it normal in a residential PV installation to not have anyone notice there is a problem until the annual true-up shows up and the customer owes a bunch of money? Is the monitoring just ignored all those months?
    Since the HO still had half a system the POCO was paying him something. I'm guessing the HO is looking to be made whole for the lost revenue. For me, it would depend on when the HO should have known something was wrong. If he's suddenly getting only 1/2 the output he should have spoken up right then, unless the fuses blew within the first month.

  9. #39
    Join Date
    May 2011
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    4,693
    Quote Originally Posted by pv_n00b View Post
    I don't generally have anything to do with residential work so I don't know this but is it normal in a residential PV installation to not have anyone notice there is a problem until the annual true-up shows up and the customer owes a bunch of money? Is the monitoring just ignored all those months?
    Yes it's normal, unfortunately. It depends on the homeowner and they run the gamut. Many watch it like hawks, while others have no clue. Half the time the monitoring data link is down anyway when a production issue arises , because the connection has been unplugged from the router, or the wi-fi password got changed or whatever. We work pretty diligently to get monitoring set up and running at installation time, but we just don't have the resources to monitor the monitoring. The companies that did leasing systems were obligated to do that; I think that's part of the reason many went under or have downsized and moved away from that model.

  10. #40
    Join Date
    Jan 2012
    Location
    CA
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    527
    exactly. some home owners check output frequently ....others only notice the big annual bill.

    in this case, there was no monitoring.
    he does have large LCD displays on the inverters.

    Most of my DC systems have no monitoring from... say 4 or more years ago.

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