Trouble with an existing Pv system Schott Asi 105w panels

[Snoopdog1]

Hi Guy after your best advice, been along to see a customer who is having trouble with his system which has been up and running for just over Four years and the original installers are no longer in business.

He has approx a 17kw system of Schott Asi 105 w panels on the roof Appox 162 info sketchy as limited info in handover pack, The system is wired between two SMA trip power 8kw investors. Three strings to each invertor

Both investors have the same fault and not producing energy solid red light with flashing green 3501

to me indicating low insulation resistance and SMA technical. On testing inflation resistance at 500v my lowest readings to earth are around 4meg ohms in the worst instance , so it's not great but above 200k ohms.

Sma am tell me the invertor is not compatible with those panels , but it's worked for four years. But can not give me a solution. Is their any one on here with experience with this Schott Asi panel I believe it's thin film. Any advice greatly appreciated. Thanks in anticipation

 

[SibertSolar]

Older thin-film panels often required the +ve or -ve DC branch earthed, hence why SMA might be saying they are incompatible with their TL inverters (no galvanic isolation) perhaps.


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[Gavin A]

don't think that applied with schott, which were framed panels.

Thin film panels have much worse capacitance which makes them more prone to IR cut out in cold / damp weather (including the dew at dawn when the inverter does that IR test at start up).

an installer with a grid guard code can adjust the insulation resistance downward from the initial 1MOhm, as long as it's testing out ok.

That fault can also indicate that there's water been getting into the connectors if not sealed properly, but in that case the IR tends to be significantly lower. Once it's up and running you can check the readings via the sunny explorer software.