Microinverter Problem?

[sensij]

Thanks for the feedback all. Once I hear from SunPower with their take on this issue I will post it here. Just a FYI. the 260V occurs on all the microinverters, but only a few shut off on my 34 panel system.

34 of them? They can only be wired 12 max per string... do you have 3 or 4 strings going into an AC combiner or sub-panel before running to your service panel?

The easy guess would be it is the last one or two panels on the string (with the physically longest circuit) that are tripping, but there are other reasons why those particular panels could be the first to trip.

In the chart that you copied showing 260 V, what it the voltage at the beginning and end of the day when there is almost no power being generated?

[mxyzptlk]

Some more information. Found the microinverter shutting down again today and not in the strongest production part of the day. Side by side comparison of the microinverter that is shutting down and the panel/microinverter next to it. The microinverter that shuts down appears to try to start back up, but then shortly goes back to 0W production. Going back through the past month's data, it appears this microinverter was working fine a week or two ago, but something changed and now it does this on/off cycling.

Current Status: Working	Current Status: Working
Max AC Power: 0 W	Max AC Power: 253 W
Cumulative Energy Produced: 0.1540 kWh	Cumulative Energy Produced: 0.1938 kWh
Total Lifetime Energy: 47.6572 kWh	Total Lifetime Energy: 54.4315 kWh
Source Timestamp: -	Source Timestamp: -
Avg AC Power: 0.000 kW	Avg AC Power: 0.253 kW
Avg AC Voltage: 252.30 V	Avg AC Voltage: 249.27 V
Avg AC Current: 1.38 A	Avg AC Current: 0.62 A
Avg DC Power MPPT 1: 0.000 kW	Avg DC Power MPPT 1: 0.264 kW
Avg DC Voltage MPPT 1: 65.57 V	Avg DC Voltage MPPT 1: 57.32 V
Avg DC Current MPPT 1: -0.04 A	Avg DC Current MPPT 1: 2.65 A
Avg Operating Frequency: 59.98 Hz	Avg Operating Frequency: 59.99 Hz
Interval Energy Produced: -0.0007 kWh	Interval Energy Produced: 0.0181 kWh
Energy Produced Today: 0.1500 kWh	Energy Produced Today: 0.1900 kWh

[Mike90250]

It's possible that the components in the inverter have "aged" and changed values, which may affect the trip off setpoint.

[sdold]

I bet this is why Enphase doesn't give everyone per-panel information anymore. Sometimes too much information is a bad thing and can lead people down the wrong path.

[bcroe]

260VAC is right at the threshold of tripping out. Something to check is the difference between the
voltage at the micro outputs, and at your main box input. If there is a big difference at noon, your
copper losses are contributing to the high voltage. At night they should be the same.

One experiment, is turn off half of the micro feeds that were working, and see if the reduced line
voltage (good to measure it) allows the previously shutting down micros to stay up. Bruce Roe