Weatherman wrote:They are both the older units (M190-72-240-S12). Serial numbers start with 121401.
That was manufactured about 18 months ago. The question I have is "Where are these original-style M190s coming from?" You have received *multiple* M190IGs to date and I received one of those last September. But now we are again receiving the old-style units. The M190 I received last week was apparently manufactured last September, but the two you are getting are twice as old. I suspect they are retrieving old stock from installers and vendors since I'm sure the installers don't want to install them and the vendors don't want to sell them.
Weatherman wrote:Three of my other replacements were late 1213 and 1214 serial number units, so, perhaps, these will do ok.
I'm hopeful these 2014-built M190s contain a different assembly than the original units that we installed. Unfortunately we cannot tell since the original units do not report the version of the assembly that they contain.
I strongly suspect that the failures are related to the attachments of components to the circuit board. Often, a simple change in the design of the solder pads can resolve the issue, but you have to know how to change it. It can be quite an art to correct such problems. Did Enphase make any changes to the M190 design before 2014? Were these changes effective? I guess we will find out in a few years.
Weatherman wrote:Would have preferred to see one of the newer ones with IG and serial numbers in the 1215s, instead. I've already had one case where a replacement failed and had to be replaced. I don't want a repeat of that.
Do you know the date code of the replacement unit which failed?
I, too, would prefer to receive the M190IG replacement units, but only to a point: I now have 12 72-cell panels in my system. With the extremely cold temperatures we have had these past two winters, I am not comfortable using the newer inverters, which have a lower voltage rating, in those 12 locations. If Enphase had fixed whatever issue they had with the M190s by 2014 AND if I eventually get more than 30 M190IGs as replacements, I may end up contacting you to trade some M190IGs for 2014-or-later original-style M190s.