Enphase/panel not recognized

[wklopf1]

I have a 7.36 kw system consisting of 32 230 watt Schott panels paired with Enphase M215 microinverters. The system was installed in 2011. Last August, we had a major rain storm, probably with lightning. The next morning, two of the panels were producing only about 2/3rds the power of all the rest. After a few days, one of these quite generating altogether. The second one lasted until November before it too died. When I finally had an opportunity to check this out (my installed had gone out of business 7 years ago), I found that each junction box had one by-pass diode which appeared to be burned out. They were a dirty brown color. When I contacted the panel manufacturer, they said that the panels could be repaired by replacing all three diodes in each panel. They provided the diodes and I replaced them. The panels then had VOC and ISC readings consistent with the original specs. However, after mounting them on the roof, only one is working properly. The second one isn't seen my the Envoy. The LED on the under side is flashing green, but no power is being produced. It is my understanding that lightning nearby can short out these diodes. That would account for the reduced output. But, what caused the panels to die? And, why does the microinverter appear to be operating correctly but is not putting out power? Any help would be appreciated.

[bcroe]

My suggestion is first see if each M215 is delivering power consistent with the others, even if
not seen by the Envoy. If no, I would move a working M215 to one or other other of the panels,
to establish if the M215 or the panel is the problem.

Failed bypass diodes can cause problems, but a strike might take out more than the diodes. Voc
and Isc are good sanity checks, but they are not sufficient to assure a good panel. A bad panel
section could deliver open circuit voltage, but with very little current capacity. A short circuit test
might deliver full current from undamaged panel section(s), while the bad are bypassed. Bruce Roe

[wklopf1]

The Envoy showed 14.31KWH for yesterday. It was quite cloudy most of the day. To see if that panel might be producing power but not showing up on the display, I added the totala produced by the remaining 31 panels. That came to 14.309 KWH. So, there was no hidden power generation. Tomorrow, after it quits raining, I will swap a couple of microinverters and see what that shows me.

[wklopf1]

I traded microinverters between two panels. The zero output stayed with the panel.indicating to me that the panel is at fault.

[wklopf1]

This morning I swapped positions of two panels, just the panels. The non-production stayed with the position, not the panel. How does one check out the socket that the microinverter plugs into?

[Ampster]

Are you talking about micro inverter cable or trunk cable?

[wklopf1]

I'm asking about the socket on the trunk cable which the microinverter plugs into. I have plugged two different microinverters into it but neither produced power or was recognized by the Envoy. I did not notice any clidk when I plugged microinverters into this socket as I have on the other few microinverters which I have plugged in.

[Ampster]

I'm asking about the socket on the trunk cable which the microinverter plugs into. I have plugged two different microinverters into it but neither produced power or was recognized by the Envoy. I did not notice any clidk when I plugged microinverters into this socket as I have on the other few microinverters which I have plugged in.

It is hard to get a probe into those trunk cable sockets without risking shorting them witt the AC on. You could make up a test cable from a dead microinverter or disconnect the AC and do a continuity check to another socket. They are all parallel in the trunk cable.
I reread this thread and didnt see what you had done to reach the conclusion that it is the trunk cable and not the microinverter. Have you moved the micro inverter to a known section of working trunk cable?

[bob-n]

The "click" comes from cable locking tabs, not from the contacts, so even if you didn't hear a click, it could still be making good contact.

[wklopf1]

It is hard to get a probe into those trunk cable sockets without risking shorting them witt the AC on. You could make up a test cable from a dead microinverter or disconnect the AC and do a continuity check to another socket. They are all parallel in the trunk cable.
I reread this thread and didnt see what you had done to reach the conclusion that it is the trunk cable and not the microinverter. Have you moved the micro inverter to a known section of working trunk cable?

I have had two different microinverters and two different panels on this socket to the trunk cable with the very same results. The microinverters and panels worked properly at other locations. So, it seems to me that the socket must be the problem. The plug from the microinverter is fully inserted. It can not go any farther, so it seems to me it must be the socket.