Enphase/Schuco failures

Logically, the top row of the panels will be subject to the most heat on the back side of the panel. I expect its a thermal failure of the Enphase electronics. Heat rises and any heat absorbed by the lower rows rises behind the panels and heats up until it exhausts at the top panel.

Schuco is long gone out of the market so unless the installer has some spare panels sitting around, all he can do is change out the microinverters. Given the panel rating if sounds like the microinverters are the earlier 190 watt Emphases that have a high failure rate. I expect that if the top row is having issues now, you will have issues later on the lower rows.

Welcome to the world of customer product testing. Enphase lost money on every earlier microinverter to try to buy into the market and it looks like they left long term reliability testing to the customer. They are still in business so they are still honoring warrantees and maybe you and many others will luck out until the warranty runs out. At some point you could upgrade the microinverter to a newer model Enphase which in theory has better reliability

After measuring panel temps. by hand about 70 + times over the last year or so on the same array, I've found that the temp. distribution varies as f(wind vector).

Some general observations, valid for my array only, but perhaps somewhat applicable for some other situations:

- North wind usually results in top of array panels cooler than bottom of array panels.
- Prevailing westerly winds make west side of array cooler than east side and similar for east winds that make the east side of array cooler than west side. In either case the temp. top/bottom stays about the same.
- South winds usually result in the bottom of the array being cooler than the top.

- Still or light, variable wind results in a more uniform temp. over the array, and that temp. tends to be highest from the ambient temp. over other conditions

As wind velocity increases, the array temp. tends to become more uniform and a bit closer to the ambient temp.- the higher the wind velocity, the closer to ambient temp. the array tends to get.

So, sometimes the panels at the top of my array are warmer, sometimes not.

Also, FWIW, I have noticed the backside of the top row of panels and their supports are "maybe" a bit dustier/dirtier.

BTW: Small correction : Hot air rises in a gravity field as a result of a change in its density. Heat moves from where it's warmer to where it's colder.

Take what you want of the above. Scrap the rest.

It could be that they are running hotter, or that they are at the end of a wire and are running at a higher voltage. If you have an Envoy, have you logged into it and looked at the event logs after any of the failures?

Are these the 190 Watt inverters?

The error being thrown is always "AC Voltage Out of Range" and yes, they are M190s.

I think it may be worth reviewing this set of forum postings from the Home Power proinstallers forums. It definitely a barebones forum but seeing some reports of failure rates of up to 25% in an array leads me to believe that its highly likely that the 190s are the problem.



Luckily for me, I don't have any microinverters on my three arrays, but I expect this is definitely an ongoing black eye for installations with microinverters.

I would say it's a black eye for the M190, and Enphase if they don't take care of the customers. I don't have any concerns about the M215s nor would I discourage anyone from using them, at least until they start failing in large numbers too, which I haven't seen (yet).

Call Enphase and open up a ticket to update your firmware if it hasn't been done already. I recently had one with the AC Voltage Out of Range and they made a change to accept a wider voltage range and the problem went away.

Could be a voltage issue due to voltage rise at the inverters. Seems counterintuitive but long cable runs will make the voltage rise at the inverter

As far as the panels go if one goes out it is easily replaced with any panel of similar size and wattage.

Switching to the M215 or M 250 would mean rewiring as these use a trunk cable and do not plug together as the 190's did.