RegGuheert on January 26, 2017 wrote:I may have just experienced the first failure of a four-generation inverter including an integrated ground. (To my knowledge, all failures of M215s that I have recorded to date were the early ones without the "IG" suffix.) I currently have four of the latest-style fourth-generation M215IGs on my roof that include the metal case. They were built in week 45 of 2015. One of those four inverters malfunctioned yesterday. It had a dropout at about 12:30 PM with no event recorded in the log. Then at about 2:00 PM it stopped producing power. About an hour later it reported "DC Power Too Low" in the event log and did not produce any power for the rest of the day.
That was the first failure of an M215IG that I experienced and I have now had a second one fail on Wednesday of this week, June 20, 2018. This failure was also from that first group of four M215IGs which I purchased which came a metal case. (The 24 M215s I had purchased prior to those had come in plastic cases.) I will call Enphase on Monday to report this failure.
As a result of this failure, I decided to pull out those M215s in metal cases and put them into their own row (as if I didn't have enough rows in my spreadsheet
for my system already!). They currently live in Row 137 of my MTBF spreadsheet
. Those four inverters were put into service just two years ago, so they have a miserable MTBF of only 4 years now. That contrasts with the 12 M215IGs with plastic cases that have early 2014 date codes which I purchased from QueenBee and installed four years ago. Those have experienced no failures after 48 device-years of operation. I also have 12 more plastic M215IGs built in the middle of 2014 which have experienced no failures even though they were installed at the same time and on the same roof as the metal units. Finally, in March 2017, I installed one additional M215IG with the metal case with a date code at the very end of 2016 which has not failed. (Coincidentally, the replacement Enphase sent me for the previously-failed unit has a date code very close to the one for this unit.) In other words, the MTBF of the *plastic* M215IGs on my roof is still undetermined with over 72 device-years of service while the MTBF of the *metal* ones is (somewhat) established at only about five years.
I also have nine M250s in the plastic cases which have operated flawlessly for the past two years. But in 2017 I purchased 24 M250-72s in metal cases. Only 12 of those have been in service and only for about 5 months, so I only have about five device-years on those inverters. No failures so far.
I'm hopeful that all of my metal-can fourth-generation Enphase inverters are not as bad as that first batch of four that I purchased!
Does anyone else out their have M215IGs or M250s (either 60- or 72-cell) with metal cases on your roof?