Hi Guys

I would like your opinions on possible issues with one of my PV Panel Strings.

I am not sure iof I may have missed anything out and maybe there is an easier solution.

I have a 16KW DEYE with three Strings on in it.

JA Solar 455W Mono panels, Open Circuit Voltage: 49.85V, Short Circuit Current: 11.41A

On West facing PV1 I have a 2P8S string of JA Solar 455 Watt mono panels

On East facing PV2 is a 2P6S string of JA Solar 455 Watt mono panels

I noticed that the PV1 string's production has gone down since end of Dec.

These are the numbers from November, PV1 Blue, PV2 Yellow

These are the numbers in Jan

As you can see, PV1 is no longer out producing PV2

This morning was overcast and I decided it was a good opportunity to disconnect each of the parallel strings to see if one of the parallel strings was faulty/disconnected.

This is with the bottom 8S string disconnected.

This is with the top 8S string disconnected

This is with both strings connected again 2P8S.

There seems to be a voltage drop issue with the top string of panels in the 2P8S configuration which to me would seem to indicate a faulty panel.

I am going to check for hot spots/faulty diodes with my FLIR camera and check the connectors as well for any heat when the sun comes out again.

Any other suggestions anyone?

Make up a long jumper lead (bridge 4 panels) and test various 4S configurations.

7 hours ago, Sc00bs said:

Hi Guys

I would like your opinions on possible issues with one of my PV Panel Strings.

I am not sure iof I may have missed anything out and maybe there is an easier solution.

I have a 16KW DEYE with three Strings on in it.

JA Solar 455W Mono panels, Open Circuit Voltage: 49.85V, Short Circuit Current: 11.41A

On West facing PV1 I have a 2P8S string of JA Solar 455 Watt mono panels

On East facing PV2 is a 2P6S string of JA Solar 455 Watt mono panels

I noticed that the PV1 string's production has gone down since end of Dec.

These are the numbers from November, PV1 Blue, PV2 Yellow

These are the numbers in Jan

As you can see, PV1 is no longer out producing PV2

This morning was overcast and I decided it was a good opportunity to disconnect each of the parallel strings to see if one of the parallel strings was faulty/disconnected.

This is with the bottom 8S string disconnected.

This is with the top 8S string disconnected

This is with both strings connected again 2P8S.

There seems to be a voltage drop issue with the top string of panels in the 2P8S configuration which to me would seem to indicate a faulty panel.

I am going to check for hot spots/faulty diodes with my FLIR camera and check the connectors as well for any heat when the sun comes out again.

Any other suggestions anyone?

Just break the 2P and run each set of 8S and compare them if they face in the same direction. Once you know which string you can do the 4S one by one and compare again.