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Hello,
I have a system with 30 BP 2150S monocrystalline 150w panels, set up in 3 strings of 10. System is 11 years old, located in the desert.
Recently had a new inverter installed because the old one failed. SMA SB5000US-12.
The inverter ran for 1 day after inverter installation then failed with 'AFCI disturbance' error. Apparently this means it detects arcing somewhere in the system?
I started troubleshooting by connecting 1 string at a time until it failed. Then when I found the bad string (#3) and checked the Voc and Isc of each panel. I found one that had visually the worst corrosion and removed it from the string. It measured fine however.
System ran for a few more days and then came back with the error. So I removed that string #3 entirely. It ran a few more days and failed again.
I have checked the Voc and Isc of every panel and they are close to the spec. Say 39-41v instead of 42.8 in direct sunlight.
I also checked all wiring from the installer at the disconnect box, inverter, and junction boxes on the roof and found nothing loose.
-8 panels have visible corrosion on the terminal looking at the front side, where it passes through to the diodes on the back side. They measured Voc and Isc fine however. I am in process of trying to warranty replace them with BP.
-I had 3 panels warrantied 2 years ago that failed for this same issue. (Corroded and then glass shattered starting at the terminal)
-I suspect all panels will eventually fail due to this problem based on what I am seeing.
-If there is arcing, likely it has existed for some time and I only know now because the new inverter detects it?
-Not sure if the corrosion I see is the problem or not.
What am I missing?? How else can I try and find what is causing the AFCI fault?
Thanks!
I have a system with 30 BP 2150S monocrystalline 150w panels, set up in 3 strings of 10. System is 11 years old, located in the desert.
Recently had a new inverter installed because the old one failed. SMA SB5000US-12.
The inverter ran for 1 day after inverter installation then failed with 'AFCI disturbance' error. Apparently this means it detects arcing somewhere in the system?
I started troubleshooting by connecting 1 string at a time until it failed. Then when I found the bad string (#3) and checked the Voc and Isc of each panel. I found one that had visually the worst corrosion and removed it from the string. It measured fine however.
System ran for a few more days and then came back with the error. So I removed that string #3 entirely. It ran a few more days and failed again.
I have checked the Voc and Isc of every panel and they are close to the spec. Say 39-41v instead of 42.8 in direct sunlight.
I also checked all wiring from the installer at the disconnect box, inverter, and junction boxes on the roof and found nothing loose.
-8 panels have visible corrosion on the terminal looking at the front side, where it passes through to the diodes on the back side. They measured Voc and Isc fine however. I am in process of trying to warranty replace them with BP.
-I had 3 panels warrantied 2 years ago that failed for this same issue. (Corroded and then glass shattered starting at the terminal)
-I suspect all panels will eventually fail due to this problem based on what I am seeing.
-If there is arcing, likely it has existed for some time and I only know now because the new inverter detects it?
-Not sure if the corrosion I see is the problem or not.
What am I missing?? How else can I try and find what is causing the AFCI fault?
Thanks!
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