PV repair

System
System Posts: 2,511 admin
in Advanced Solar Electric Technical Forum #1
Hello everyone:
I am new to the forum and if this question has already been asked I apologize.
I recently had a backyard tech attempt to add a panel to my existing 5 panel (24volt) system. He apparently had it hooked up incorrectly and after the sparks flew I no have no output on the panel, which by the way is not currently in the system.
I am guessing a diode is bad but there may be more damage I cannot see.
Does anyone know of a repair person in Arizona?
Any help would be GREATLY appreciated. You can also email me at wa7ups60@yahoo.com

Thank you in advance!!

Bob in Yucca Az.
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Comments

  • System2
    System2 Posts: 6,290 admin
    #2
    Re: PV repair

    Hopefully it's only the bypass diode, or diodes shorted out. If you know it to see it, you can disconnect one end and see if you get your output back. It should definitely be replaced if that's what it is. He may have wired the panel up reverse polarity, which would take out the diode/diodes.
    If you have and can properly use a good meter, you should be able to check the diode in circuit and get a good idea if its shot.
    Good luck
    Wayne
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  • Roderick
    Roderick Solar Expert Posts: 253 ✭✭
    #3
    Re: PV repair

    If it has a junction box on the back that you can open, maybe there's a small fuse inside?

    I'm very curious as to what you find, so please post an update later. This will be new learning for me, probably for some others, too.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #4
    Re: PV repair

    sorry to hear of your dilema bob. i hope you will make that person pay for the damage, but it does sound like a blocking or bypass diode possibly. this is equivalent to connected 2 batteries you intend to be paralleled and go + to - causing a short with full current minus resistive losses. this would be enough to blow a diode or fuse if that's in there too. you didn't mention the pv you have (make and model) and if the junction box is sealed or openable. being you are a ham i'm guessing you have a dmm already or at least can access one, but it's a question of accessability right now to test it. if a fuse or diode blew i'd guess your pv itself to be fine. now i'm not sure, but if either of those aren't the case, the power of 2 pvs with double the voltage and full current may possibly melt the cell interconnections and none of this is coverable for warranty.
    also in question would be the other pvs if they are ok as you didn't say.
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  • Roderick
    Roderick Solar Expert Posts: 253 ✭✭
    #5
    Re: PV repair

    By the way, what kind of panel was it? That will help us determine whether there was a blocking diode included inside.

    If there are bypass diodes inside, I would think they are unlikely to be the trouble if the panel is putting out zero, as all of the diodes would have to be shorted.

    If you have a DVM (or ohm-meter) handy, try checking whether the panel reads completely open both ways. If so, I would start to suspect an open connection between the solar cells, or a blown fuse, with the latter being far more likely.

    These are all just guesses, though.
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  • System2
    System2 Posts: 6,290 admin
    #6
    Re: PV repair

    Hi again everyone, thank you for all of the replies to my dilemna.
    The panels that I am using are 24 volt BP 2140's which are sealed so not quite as easy to access the panel to check for physical damage to the
    diode(s) I have not noticed any degredation from the other panels so I believe the problem is dedicated to the one panel.
    Using my VTVM I have very low voltage output and I will check the diode in line as I am not quite sure how to open up the sealed junction box.
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #7
    Re: PV repair

    the sealed boxes are sealed to weather better, but primarily to keep people out of there (voids warranty) so your recourse is to get that guy to buy you another pv. you can try contacting bp regarding the pv, but they'll probably tell you it's scrap. after the scrap determination you may wish to try and gain access into the box and maybe even bypass it all to see if that pv will output. if not, then odds are the cell interconnects probably fried and you can try to salvage the individual cells. good luck on that as that's not easy to do.
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  • System2
    System2 Posts: 6,290 admin
    #8
    Re: PV repair

    Hi Niel,
    Well, I did not contact BP however since I figured I had nothing to lose, I attempted to gain access to the J box today. It is completely epoxy sealed and I am slowly removing it with a router tool.
    I can only see one burn mark on the panel and that is directly above the jbox so I am hopeful that it is a burned diode or connection.
    I do appreciate the feedback and will keep you all appraised when and if I get it open.
    BTW when I do a voltage test, the panel (24v) shows 2v output in full sun making me think it is most likely the diode.
    Thanks again
    Bob
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  • niel
    niel Solar Expert Posts: 10,300 ✭✭✭✭
    #9
    Re: PV repair

    good luck and let us know the verdict.
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