Sunny Boy TL Series Arc Fault

dgrilleydgrilley Registered Users Posts: 1
My solar was installed 4 years ago and has worked perfectly up until this past Sunday when I got the dreaded Arc Fault Check DC Power Generator 4301 alarm.   I have the TL 5000 SMA inverter.   My system was under a 10 year warranty and was designed and warrantied by a company that has since went out of business.   The electrical contractor that installed the system is still in business but so far getting in contact with them has been like pulling teeth.  I have emailed, sent a web site inquiry, and called what appears to be a service that answers phones for them but so far have been unable to talk to anyone in 3 days.   I'm going to assume that I have no recourse as far as the warranty goes and while I'm willing to pay to have it permanently fixed I have a lot of concern based on things I've read that the issue may keep returning.   As far as basic troubleshooting I've so far look up on the roof and found a pigeons nest underneath the panels although it doesn't look as if there is any wiring or obvious issue near the nest.   On the ground side I opened the box below the inverted and tried to connect individually my A and B array of panels, but I think maybe I would need to reset the fault for that test to have been valid?   Everything inside this box looks clean.   I've also opened the AC manual disconnect box and in here I actually do see some contacts that are somewhat black.  My question is is it possible for an arc in the AC disconnect box to trip the inverter and give a DC Arc Fault?   If anyone has any suggestions on how I might be able to troubleshoot this further I'd appreciate it.  I'm willing to do anything from the utility panel up until the solar panels, but I don't want to have to lift and move around solar panels.   Any suggestions also on what to look for if I hire someone outside the installer to come look at this as so far I can't get in contact with them?   


  • Dave AngeliniDave Angelini Solar Expert Posts: 5,287 ✭✭✭✭✭
    What does SMA say? Have you told them what you wrote here? 

    I doubt the AC side could do this but why don't you just jump the contacts that look bad. There should be a breaker upstream that you can shut down for this test.

    I have made a small fortune replacing arc fault PCBs and so this can be pretty common. Especially ABB types. Yes you need to reset the AFCI for each test.

    SMA has had me replace a few for people who are out of business as there are few who want to travel up into the rurals where I live.
    They pay about $300 and expenses so I think you can convince them to get someone. First you have to diagnose and prove it to them.

    Your test idea is a good one on separating arrays. Do it again. That should prove it is not the wiring out to the array. Good Luck
    "we go where power lines don't" Sierra Mountains near Mariposa/Yosemite CA
    E-mail [email protected]

  • billybob9billybob9 Registered Users Posts: 141 ✭✭
    It looks like were in the same boat with a SMA 5.0 inverter on 2 strings. If you read my post here "2 or 3 strings" you'll see I've MAXED out the SMA inverter with solar wattage. If you add up the wattage on both your strings and it is over 4800W then this might be the problem. I think what may be happening is when most home systems used 250W panels, 16 panels on a string was standard. Now 300W and 320W have taken over and 16 of these panels is over the size of a 20A breaker at the box. On low Voltage months this would not be a problem but peak months might get you to that breaker tripping point.
  • billybob9billybob9 Registered Users Posts: 141 ✭✭
    Sorry, that is 16 panels on 2 strings
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