Enphase field MTBF: M190: ~36 Years M215: ~316 Years M250: >357 Years

[pclifton]

Sorry to hear of your M250 failure.

Line 219 - no failures but four of the M250s have been removed and replaced with S280s in July of 2016 to take advantage of the higher power rating of the S280 with the SolarWorld 275watt modules . Number of installed M250s on that spreadsheet line is now eight.

Line 236 - no failures of the S280s attached to the Sharp 235watt modules.

Need to add another line for four S280s that are attached to the SolarWorld 275watt modules .

Thanks!

[RegGuheert]

Line 232: No failures on my S280's.

Updated. Thanks! You now have over 25 device-years of operation without any failures.

Sorry to hear of your M250 failure.

Line 219 - no failures but four of the M250s have been removed and replaced with S280s in July of 2016 to take advantage of the higher power rating of the S280 with the SolarWorld 275watt modules . Number of installed M250s on that spreadsheet line is now eight.

Line 236 - no failures of the S280s attached to the Sharp 235watt modules.

Need to add another line for four S280s that are attached to the SolarWorld 275watt modules .

Thanks!

Thanks, pclifton! Since I do not have any installations of S280s before September of 2016, I'm wondering if your July of 2016 date is a typo. Since you provided an update in February of 2018 without a mention of this change, I am going to put your latest changes in as of July of 2018.

Please correct me if my correction is in error.

With the above changes, the overall MTBF of the M250s with one total failure now stands at 450 years. The overall MTBF of the S280s with no failures is above 154 years.

[RegGuheert]

One more note: A second one of these early, out-of-warranty M250s is also showing signs of imminent failure. I will report here if it fails completely.

It has been sunny for the last day-and-a-half and I can see that TWO more of the remaining eight out-of-warranty M250s are failing. The failure mode is that they always produce power, but they will not produce above a certain power level. One seems limited to about 100W while the other is limited to about 120W. Over the past two days, one harvested 70% as much energy as its neighbors and the other harvested 75% as much. At that level, Enphase would consider them both failed (assuming we could get seven straight sunny days around here).

I find it very strange that three of the nine early-build M250s that I own have decided to fail within a few weeks of each other after years of proper operation. I must say that I regret purchasing these used units. Fortunately, all the other inverters I have purchased are/were new with warranty. I decided a year or so ago to purchase spares to cover these nine "just in case". I didn't expect to need them so soon!

[pclifton]

One more note: A second one of these early, out-of-warranty M250s is also showing signs of imminent failure. I will report here if it fails completely.

Wow, that is very unusual to have so many fail in the same timespan! I was going to ask about the failure mode, but you answered that. I saw a similar failure mode on many M190s, but like you, I am very disappointed to see it in the M250s as well.

Like you, I purchased enough spares to completely replace all my inverters, except my spares are S280s. It will be interesting to see how this all plays out. BTW, you are correct, the install date for my four S280s replacing the M250s was 2018 -- sorry about that.

Respectfully,
Ken Clifton

[RegGuheert]

I find it very strange that three of the nine early-build M250s that I own have decided to fail within a few weeks of each other after years of proper operation. I must say that I regret purchasing these used units. Fortunately, all the other inverters I have purchased are/were new with warranty. I decided a year or so ago to purchase spares to cover these nine "just in case". I didn't expect to need them so soon!

It's official. Three of the nine early-build M250s have failed, and I have updated the spreadsheet to show the failures. They failed less than five years after their manufacture date. That brings the overall MTBF of the M250s in the spreadsheet down to just 150 years.

I'm still stumped by the three nearly-simultaneous failures. I suspect electrical stress must have been involved, but that begs the question of why the other 6 inverters of that type (and the other 45 inverters of other types) did not fail due to the same stresses.

I'm not happy I purchased these 9 used inverters. OTOH, it makes me glad that all of the other units I own are still under warranty!

[ltbighorn]

Row 226: No failures/issues with my 12 M250s as of 2019-04-18.

[Computerizer]

I have an update for you; I have had a failure.

My system is on row 224 of the spreadsheet, in Bellingham, WA. https://enlighten.enphaseenergy.com/pv/ ... 8/overview

I actually have 24 M215s with 250W panels that came online Oct 4, 2013 and 24 M250s with 255W panels which came online March 26, 2014.

One of the M215s failed on July 14, 2019. It was replaced under warranty with an M215-IG on July 25, 2019.

All other inverters continue to perform normally.