GetOffYourGas said:
I have officially lost the third M215 inverter.
I'm sorry to hear that. That failure brings the MTBF of your system down to only 24 years, which is HALF of what I am seeing with my M190s. Additionally, this third failure brings the overall MTBF of M215s which I am tracking down to 460 years. That is a good number, but I will say that the M190s had a good number once-upon-a-time, also.
I am now fully convinced that the original batch of M215s included the new case and the Engage cabling system, but that they employ an electrical architecture very similar to the M190s. I believe that only with the M250s and M215IGs did Enphase manage to eliminate the electrolytic capacitors (along with other enhancements).
I guess the saving grace here is that ALL M215s have the 25-year warranty. I suppose it was Enphase' plan all along to replace failed first-run M215s with M215IGs once those became available.
GetOffYourGas said:
It was a very hot July, at least for Syracuse (day time highs breaking 90F for about two weeks out of the month). The inverter would start out the day just fine. As the day got hotter and the sun got more direct, the inverter would flicker for about an hour and then cut out completely. Sometimes it would come back to life in the evening, other times not until the following day. It finally gave up the ghost and hasn't been on at all for about a week.
Nearly every day in July was over 90F here. Did you have a lot of thunderstorms in July? We certainly did!
GetOffYourGas said:
Both previous failures were replaced by the M215-IG model.
That's good! I'm pretty sure that none of the M215 failures I have recorded to date are the M215IG units. Unfortunately, I have no way to know since I didn't tracked manufacturing date codes for the failed units.
GetOffYourGas said:
I was speaking with a friend of mine, and I realized that I have nominally 230W panels driving these inverters. They are rated at 230 +/- 10%, which would be 207-253W. The 215 is the inverter rating, right? As in 215W? Is that input or output? Did my installer undersize the inverters, and could that be contributing to their high failure rate?
As QueenBee said, the M215s can put out 225W. IMO, you can go quite a bit higher than 230Wp on your modules with the M215s and be in good shape. I also don't think this hurts your production, either. I have 235Wp modules and my M190s, M215IGs and M250s all harvest about the same amount of electricity through the course of the year.
That said, it IS still possible that your high failure rate is caused by something that your installer did wrong. For instance, if he did not run a grounding wire to all of the microinverters, that *might* cause a reliability issue. But even if that is the case, that particular problem goes away once the units are replaced by M215IGs (assuming the wiring in the Engage cable is correct).