Half of the system stopped working.

[astroprojector]

Hello,

I was wondering if someone with SolarEdge inverter can help.

I have 34 panels 10Kw system. The 34 panels divided into 2 lines with 17 panels per line. The system was installed August 2016 and was working without any issues. Last week one of the lines stopped working. From what I could gather after conversations with SolarEdge support is that sometime last week there was a power surge from the LADWP and that caused line shortage in my system. In fact while I was inspecting the system, one of the connectors, that connect optimizers, was completely burned out with large melted whole on one side. The system showed that it could communicate with 29 out the 34 panels, however one line was completely dark blue all day long. I turned OFF the system and replaced the burned out connector. Turned the system ON again and now the system just sees 17 out of 17 panels. I decided to check if all of the optimizer are working. The non-working line is divided into 3 sections of 6, 9 and 2 panels. I turned OFF the system again, opened junction box for each section to see what voltage I get. If all optimizer are working I should get 6, 9 and 2 volts for each section and yes that is what I got. The sections displayed 6, 9 and 2 volts. So, my assumption is that all optimizer working.

If that is case then
1. If the optimizers working then why one line does not work?
2. Is there something in the inverter not registering properly?
3. Should have the inverter protect the system from the power surge?
4. Any ideas what can be done?

[max2k]

Hello,

I was wondering if someone with SolarEdge inverter can help.

I have 34 panels 10Kw system. The 34 panels divided into 2 lines with 17 panels per line. The system was installed August 2016 and was working without any issues. Last week one of the lines stopped working. From what I could gather after conversations with SolarEdge support is that sometime last week there was a power surge from the LADWP and that caused line shortage in my system. In fact while I was inspecting the system, one of the connectors, that connect optimizers, was completely burned out with large melted whole on one side. The system showed that it could communicate with 29 out the 34 panels, however one line was completely dark blue all day long. I turned OFF the system and replaced the burned out connector. Turned the system ON again and now the system just sees 17 out of 17 panels. I decided to check if all of the optimizer are working. The non-working line is divided into 3 sections of 6, 9 and 2 panels. I turned OFF the system again, opened junction box for each section to see what voltage I get. If all optimizer are working I should get 6, 9 and 2 volts for each section and yes that is what I got. The sections displayed 6, 9 and 2 volts. So, my assumption is that all optimizer working.

If that is case then
1. If the optimizers working then why one line does not work?
2. Is there something in the inverter not registering properly?
3. Should have the inverter protect the system from the power surge?
4. Any ideas what can be done?

My opinion only:
1. I'd recheck the connector you repaired.
3. I doubt power surge caused this. Most likely bad contact at that connector finally led to its failure.

If I understand correctly how Solar Edge inverters are wired the wire connecting optimizers to the inverter is the actual power wire which brings DC power in so I'd be triple careful working in that area as I don't see how turning OFF the system would guarantee no dangerous voltage on those DC input wires.

[sensij]

The whole SolarEdge safety system, accepted for 2014 NEC compliance, is built around the requirement that optimizer output falls to a safe 1 V level when there is a fault or the system is turned off or disconnected. Care is *always* needed, but the system should just not be capable of producing high voltage when shut down for service.

Attempting to re-pair the optimizers is probably the first step. Have you already tried going through the pairing procedure again? I probably created a small arc a couple months ago when I flipped the rotary disconnect to OFF while the system was producing full power, and needed to go back through pairing to get the optimizers working again. Support reminded me to always flip the toggle switch to off and allow the DC voltage to fall before turning the rotary switch.

[astroprojector]

The whole SolarEdge safety system, accepted for 2014 NEC compliance, is built around the requirement that optimizer output falls to a safe 1 V level when there is a fault or the system is turned off or disconnected. Care is *always* needed, but the system should just not be capable of producing high voltage when shut down for service.

Attempting to re-pair the optimizers is probably the first step. Have you already tried going through the pairing procedure again? I probably created a small arc a couple months ago when I flipped the rotary disconnect to OFF while the system was producing full power, and needed to go back through pairing to get the optimizers working again. Support reminded me to always flip the toggle switch to off and allow the DC voltage to fall before turning the rotary switch.

This is how I normally turn OFF the system. Red toggle switch, wait for countdown to finish, then rotary switch, then breaker. Turn ON the system in the opposite direction, breaker, rotary switch, red toggle switch. Tried several times, the inverter still only sees 17 panels.

[sensij]

Ok, you have rebooted it. Have you redone the pairing procedure? Press and hold the push button next to the red toggle switch for several seconds. If you let go too soon, it just puts you into the configuration menu without reconnecting the optimizers.

[astroprojector]

Ok, you have rebooted it. Have you redone the pairing procedure? Press and hold the push button next to the red toggle switch for several seconds. If you let go too soon, it just puts you into the configuration menu without reconnecting the optimizers.

Yeah, I did not do that. Just found the video on how to do it. Hold the green button for 8 sec and then turn the ON the red toggle switch within 5 sec after that.

[astroprojector]

Re-paring worked. Thank you for the help.

[sensij]

Re-paring worked. Thank you for the help.

great! I'm glad what I learned from my mistake a couple months ago could help someone. Thanks for posting.