TonyWilliams
Well-known member
RegGuheert said:
Can't find how to turn on and off of those:
Enphase field MTBF: M190: ~36 Years M215: ~316 Years M250: >357 Years
- Thread starter RegGuheert
- Start date
Help Support My Nissan Leaf Forum:
Can't find how to turn on and off of those:
RegGuheert
Well-known member
Opps! I forgot one step!TonyWilliams said:
You cannot see anything other than Power Produced for the Full System. Click where it says that and pull down to '35 Microinverters'. Then select one from the list. It will put you back into the View tab to show you which one you selected. You can select from here instead, if you like. Then select the Graph tab again and you should see the other options at the bottom of the graph.
RegGuheert
Well-known member
I have updated the MTBF spreadsheet to include all failures observed until today. More M190 (and M380, which is a duplex M190) failures are observed, mainly on systems that already had multiple failures. One M380 system went from FOUR total failures (two pairs) to FOURTEEN total failures (seven pairs) out of fifty total inverters since last checked in April. We have had a LOT of thunderstorms this year, some quite severe. I'm really starting to think the high failure rates may be due to lightning.
Tinkeringcaveman
New member
- Joined
- Jul 6, 2013
- Messages
- 2
I read this thread with interest as I have a solar array with 16 enphase microinverters in Troy, Illinois. I installed the array in May/June 2011. As of June 2013, I have had 5 microinverters fail. I believe I have the M190 inverters.
Here's a web page I use to track my system (I haven't updated it lately):
https://sites.google.com/site/tinkeringcavemansolarproject/" onclick="window.open(this.href);return false;
Here's a link to the enphase site:
https://enlighten.enphaseenergy.com/public/systems/JSQ217175" onclick="window.open(this.href);return false;
It does not appear that this site was used in the above-reference study of inverter failures.
All of the inverters failed at various times in the months since after last year's record heat wave, when my thermometer indicated an ambient air temperature of about 110 degrees was reached on several days. Naturally, the roof temperature is going to be significantly higher.
I have ordered some thermistors, and plan to get an IR heat sensor gun to try to measure the temperature on the roof.
I have been questioning whether I got a bad batch or whether it is entirely a temperature stress problem. Unfortunately, I have not kept rigorous records of when these models failed with respect to temperature, and previously had no way to measure the roof temperature.
If I had to do it all over again, and considering that global warming ain't gonna let up, I would probably use a main inverter at ground level. I'm really getting tired of climbing on the roof.
Here's a web page I use to track my system (I haven't updated it lately):
https://sites.google.com/site/tinkeringcavemansolarproject/" onclick="window.open(this.href);return false;
Here's a link to the enphase site:
https://enlighten.enphaseenergy.com/public/systems/JSQ217175" onclick="window.open(this.href);return false;
It does not appear that this site was used in the above-reference study of inverter failures.
All of the inverters failed at various times in the months since after last year's record heat wave, when my thermometer indicated an ambient air temperature of about 110 degrees was reached on several days. Naturally, the roof temperature is going to be significantly higher.
I have ordered some thermistors, and plan to get an IR heat sensor gun to try to measure the temperature on the roof.
I have been questioning whether I got a bad batch or whether it is entirely a temperature stress problem. Unfortunately, I have not kept rigorous records of when these models failed with respect to temperature, and previously had no way to measure the roof temperature.
If I had to do it all over again, and considering that global warming ain't gonna let up, I would probably use a main inverter at ground level. I'm really getting tired of climbing on the roof.
Sorry about the failures. IMO it appears that certain batches seem more likely to fail than others. Many people will have no issues at all, while others will have significantly failures (like you). 5 / 16 is a horrendous failure rate and way above average.Tinkeringcaveman said:
Looks like 3 inverters are still down? It also looks like you have another issue with the panel/inverter 3rd from the top-right - it's consistently under-producing the rest of the panels. Hopefully just dirt but could be a panel or inverter issue as well.
Depending on the failure rate, it'd be interesting to figure out when it's "worth" going up on the roof to swap out failed parts since the rest of the array is still working fine. For most cases it's probably not worth going up for a single failure. Perhaps annual or bi-annual trips up to the roof to address issues? A single panel/inverter is only going to produce about 350 kWh / year at most unless you live in the desert.
Tinkeringcaveman
New member
- Joined
- Jul 6, 2013
- Messages
- 2
Yesterday, I did some spot checks into the inverter-reported temperatures for last summer. I looked at one of the failed modules, and one that has been operating without any problems. I would like to spend more time this week compiling data.
In both cases I examined, microinverter temperatures climbed about 150 degrees on a small number of occasions during the hottest weather. On one day, the failed inverter registered 158 degrees, while the ambient reported air temperature for the local weather station was 108 degrees.
The M190s are rated for up to 65 degrees Centrigrade--149 degrees Fahrenheit. My preliminary review of just those two modules identified seven days in 2012 when the inverter temperatures met or exceeded the design temperature.
The modules are mounted in the manner specified by the enphase literature, and the same way I see them mounted on arrays in numerous ads, magazines, and web sites.
I have more work to do, but still preliminarily believe heat is the cuplrit.
I have a brown roof, which probably does not help the situation.
I suspect a ground array or post-mounted array would not experience these temperature problems, and would have no qualms about using microinverters there. I am increasingly hesitant to recommend to anyone that they use them on rooftops.
BTW - the lower performing module you mentioned is a damaged PV module- the glass has been shattered, but it has steadily produced 80% or so of its rated output since I shattered it during installation.
In both cases I examined, microinverter temperatures climbed about 150 degrees on a small number of occasions during the hottest weather. On one day, the failed inverter registered 158 degrees, while the ambient reported air temperature for the local weather station was 108 degrees.
The M190s are rated for up to 65 degrees Centrigrade--149 degrees Fahrenheit. My preliminary review of just those two modules identified seven days in 2012 when the inverter temperatures met or exceeded the design temperature.
The modules are mounted in the manner specified by the enphase literature, and the same way I see them mounted on arrays in numerous ads, magazines, and web sites.
I have more work to do, but still preliminarily believe heat is the cuplrit.
I have a brown roof, which probably does not help the situation.
I suspect a ground array or post-mounted array would not experience these temperature problems, and would have no qualms about using microinverters there. I am increasingly hesitant to recommend to anyone that they use them on rooftops.
BTW - the lower performing module you mentioned is a damaged PV module- the glass has been shattered, but it has steadily produced 80% or so of its rated output since I shattered it during installation.
Tinkeringcaveman said:
No fun, how'd you shatter it? Pretty neat that even after this long it's till putting out 80% though.
Tinkeringcaveman said:
I wonder at what temperature it starts ramping down it's output in order to attempt to run cooler and protect it self? One doesn't have much control of the roof temp if they've installed everything in the standard manners so we have to rely on the inverter to protect it self :/
I think it's important to remember that each generation they've improved the design. If we are to assume that the warranty is at least a little bit based on the life of the product I don't think it's fair to rule out microinverters because of your experience with the M190.
The next generation of microinverter, the M215 would appear to address these concerns. Warranty from 15 years to 25. Warranty now covers the labor to uninstall and reinstall the M215 and additionally covers lost production. The operating temperature was increased to 85 degrees C and the ambient temperature is 65 degrees C. Remember that the M190 is technology that was released to the market 4 years ago. Even the M215 is now 2 years old. The next generation is coming out very shortly.
If this was the case, we should be seeing a lot more failures in Arizona. Here's a site of a fellow in Tuscon I've chatted with:Tinkeringcaveman said:
https://enlighten.enphaseenergy.com/public/systems/tL4K292" onclick="window.open(this.href);return false;
4 separate arrays which have been expanded twice over the years. He has the 7 of the original M175 inverters - the rest are M190s. Only one failure so far after a number of years in the Tuscon heat - and that was one of the original M175 inverters.
Probably not. In my discussion with others a big issue is heat being radiated back through the attic onto the back of the panels. Your attic is probably in the 150F range - similar to the inverter temps. So anything you can do to help cool the attic will also help reduce inverter temps. Properly installed radiant barrier will help keep the heat out of the attic and installed under the panels will help keep the heat from going the other direction and heating up the inverters/panels.Tinkeringcaveman said:
Ground mounted systems will definitely have lower temperatures. But mounting the panels higher off the roof with some spacing between rows will also be effective. 6" off the roof instead of as close as possible as many try to get the panels will reduce temperatures boosting production as well as improving lifetime of the inverters.Tinkeringcaveman said:
I managed to grab a copy of the spec sheet (it's called the M250 and will be announced on the 9th) when Enphase accidentally put it on their website. Specs aren't all that different than the M215. Some notable differences:QueenBee said:
1. Power output: 240W nominal, 250W max
2. Efficiency improved 0.5%
3. Isolated DC circuit - GEC grounding no longer required for inverter.
drees said:
I found it interesting that apparently using only WEEBs as the GEC to the racking was not NEC/UL/etc approved? Looking at the old installation manual it appears that may have only been approved by CSA. This is certainly a very common practice here and while I don't expect my AHJ to know every detail about PV they passed my design doing so twice
megalo
Active member
Maybe they'll have a firesale on the M215s now...
RegGuheert
Well-known member
Welcome, and thanks for the heads-up on your system, Tinkeringcaveman! You have the second-highest rate of failures that I have found to date. Please keep us informed as you learn more.Tinkeringcaveman said:
No, this study is not all-inclusive by any means. The data-mining is done manually, so I can only track a relatively small number of sites.Tinkeringcaveman said:
I have added your system to the spreadsheet and will track it, but I should note that it is the ONLY site included so far that was self-selected because of a high failure rate. All others have been added because they were "discovered", regardless of the number of failures or lack of failures. While this certainly corrupts the MTBF calculation, I have all but given up on using that number (as I originally intended) since the failure rates between sites vary so widely. For instance, the MTBF for my system currently sits at 105 years, while yours currently sits at only 7 years. Another system near here has a failure rate of 387 years (although it is not roof-mounted). The failure rate for all of the M215s is currently unknown, since none have failed within the 345 device-years that I have tracked so far. However, these systems are younger, so they have not yet experienced as many thermal cycles as the M190s. In any case, I need to modify my spreadsheet so that I can track those separately.
Thanks for the temperature data. While I agree that your peak temperature has exceeded the rating of the M190 microinverters, it is far from clear that this would result in an immediate or even imminent failure. IMO, it is more likely this rating is needed for Enphase to be able to guarantee a 15-year life for the modules. The electrolytic capacitors are the most heat-sensitive components used in the M190s are rated for operation for 8000 hours at 221F. At all lower temperatures, their rate of degradation will be reduced, meaning even longer life (up to 15 years, according to Nichicon, the manufacturer).Tinkeringcaveman said:
IMO, a more likely explanation is related to either the site or some issue with a defect in the batch of inverters installed at a site. One site I am tracking has two failures AT THE SAME LOCATION, which makes me believe the site is the issue. Possibly lightning combined with installation details is involved, but I do not know.
O.K. I was going to ask the same question about that one as drees did. But I have a similar question: Why does the microinverter fourth from the left on the top row produce MORE electricity than all the others? I don't see any obvious shading of the other modules. Does it have a higher-power PV module mounted above it than the other microinverters? Or perhaps it sits in front of a window that reflects more sunlight onto the PV module?Tinkeringcaveman said:
Agreed. In other words, the premise of the thread starter has proven to be false. While there are a couple of failed inverters in the Phoenix area, I have found many more failures in the immediate vicinity of where I live.drees said:
Thanks for all the information on the M250s, guys!drees said:
Unfortunately, all the various grounding schemes simply add to the confusion installers and inspectors have about what is best. This is a challenging topic which requires a certain amount of faith in what is communicated by the NEC, the manufacturers and the inspectors to accept. While some inspectors will be open to new ways to do things, others may not be.
That was exactly my first thought! I have an old off-grid array which would do nicely with 12 M190s (since they are 72-cell modules). I would love to upgrade 14 of my M190s to M215s and move 12 of the inverters over to this other array. At some point, swapping out these inverters might make sense.megalo said:
Keep in mind that the M190 spec sheet says:Tinkeringcaveman said:
Operating temperature range: -40C to +65C
The M215 spec sheet clarifies this:
Ambient temperature range: -40C to +65C
Operating temperature range(internal): -40C to +85C
It's quite possible that the actual temperature rates are the same.
RegGuheert
Well-known member
I believe you have a typo on that last line. It should read:drees said:
Operating temperature range(internal): -40C to +85C
Possibly. However, I also wonder if Enphase made some design changes to the M215 which allowed for higher internal temperatures without damage.drees said:
In any case, I like the specs for the M215 better, since internal temperatures are generally much easier to come by than ambient temperatures in the vicinity of the inverter.
megalo
Active member
Enphase just published the spec sheet (and more on their website):
http://enphase.com/wp-uploads/enphase.com/2013/07/M250_Data_Sheet.pdf" onclick="window.open(this.href);return false;
Temp ranges:
Ambient temperature range -40ºC to +65ºC
Operating temperature range (internal) -40ºC to +85ºC
http://enphase.com/wp-uploads/enphase.com/2013/07/M250_Data_Sheet.pdf" onclick="window.open(this.href);return false;
Temp ranges:
Ambient temperature range -40ºC to +65ºC
Operating temperature range (internal) -40ºC to +85ºC
RegGuheert
Well-known member
Thanks!megalo said:
I wonder what this means:
I cannot find a warranty statement for the M250, but I'm wondering if they are backing off on it somehow.
megalo
Active member
They have a 300W / 48V DC limit, which would seem to indicate that you could use a 300W 72 cell panel with them. That would be interesting, because I could get another ~20% on my roof with 300W panels and these new inverters - but Enphase still says they are for 60 cell panels.
RegGuheert
Well-known member
I see. I'm guessing they have to sell the unit for less to be competitive in a commercial setting.QueenBee said:
BTW, looking at the specs, I would say this unit should be called the M240 to be consistent with their pervious product offerings. But M250 is clearly the better choice from a marketing standpoint!
Similar threads
