Wow!LEAFfan wrote:I have a roof temp sensor, and I believe it hit 170-180F last summer.
That would explain why we see so many failures in AZ. It doesn't explain why I see two failures out of 41 inverters on a roof near here.
What a pain. At some point this becomes unworkable for both the manufacturer and the customer.LEAFfan wrote:I don't have Enphase micros (have Honeywell/Exeltec), but Monday will be the seventh one to be replaced out of 20. The one Monday is a replacement for a replacement.
In the case of Enphase, I wonder if they will simply offer an upgrade to M215 if the failure rates get high enough.
THAT may explain why the nearby system has two failures. Or perhaps it just happened.drees wrote:Anecdotally, it seems that if a site has one failure, it appears that it is more likely to experience additional failures. It seems that there may have been some bad batches here and there resulting in premature failure.
I suspect that the roof characteristics and the installation may play a key role in operating temperatures. For instance, a roof with a low pitch and with the mounting rails down close to the roof should have lower airflow from chimney effect on a still day and thus should see higher temperatures. It may be possible to estimate roof pitch based upon seasonality of production. I wonder if a correlation might be seen there.
I have also taken the additional step of mounting the microinverters on our roof so that the outer "can" is upside down so that water could not pool in the inverter. While Enphase has said these are NEMA 6 rated enclosures and that the encapsulant would prevent water incursion, I didn't want to risk any moisture getting inside. Frankly, it was a pain to do, but who knows it it will make a difference. Perhaps it was wasted effort.
I don't think I have any M380 failures showing in my spreadsheet, yet. The signature for that should be two adjacent inverters being replaced simultaneously. That's propably because there weren't as many of those installed. IMO, it wasn't one of Enphase' better ideas.drees wrote:Specifically with the M380.
Let's hope so. If not, then Enphase may be in serious trouble.drees wrote:The M215 should be more reliable than the 190W inverters.
Agreed. And that brings us back to the title of the thread. So we watch as we see what appears to be a lower-than-predicted (by Enphase) MTBF in Phoenix. We also have roofs with multiple failures in more moderate climates like around here, which I find surprising.drees wrote:Either way, heat will speed up the failure rate of electronics, just as it speeds up capacity loss of lithium batteries.
So, like with the LEAf, the rest of us wonder what the implications are for our installations. While we have a much better warranty in place than Nissan offers for the LEAF, if the overall failure rate is high enough, then Enphase is doomed and our warranties will not cover us.
I wish I could keep this spreadsheet running long-term, but I suspect Enphase will turn off the old websites within the next few months. After that, we will be limited to anecdotal, self-reported data, which is not usable for calculating MTBF.