Inverter issues

[Dayton Johnson]

What would cause two inverters to fail "twice" within 10 yrs.? Installer says it could be a power surge (we have protection) lightning strike (no evidence of scorch or burned connectors etc.) Thankfully Fronius had the warranty in place and we dodged that bullet by two months. This type of inverter was no longer in stock so a cannibalized , salvaged spare parts version was the replacement. Seems to be working ok but for how long and next time it's full cost to me.
It would appear that solar install companies in this area are now few and far between and operate with minimum staff or part time help. It can get very costly to listen to the reasons why but the installers are guessing at best. All ideas will be passed along.

[Rob Beckers]

Hi Dayton,

In general, Fronius inverters seem to be very, very reliable. We've both been selling and installing them in the past 10 years, first the IG series, later the Primo/Symo series, and I can still easily count the number of inverters that broke on one hand. I'm not trying to be a cheerleader for Fronius, that's just my observation to date.

It is indeed unusual to have two inverters fail in 10 years, so that one has me scratching my head. Lightning can kill an inverter, but it's not a common event, I only know of a few cases where that played a role. Possibly poor power quality, something like frequent brown-outs, could have an effect. Electronics doesn't like running 'at the edge' of its envelope, but again not something I've seen to cause failed inverters (the grid around here is not great, lots of rural areas with people at the ends of long lines, and frequent grid failures).

What do you have in panels and how many panels in a string? What size inverter vs. total PV Wattage? I wonder if you are one of the cases where the PV side was vastly oversized vs. inverter rating. I could see that have an effect.

-RoB-

[Andy Rhody]

Lightning can do it.

Took out my Power One 3Kw inverter.

Cable half way down the pole burnt.

[Rob Beckers]

Dayton, you sent me an E-mail instead of posting to this thread.

Your E-mail mentions you have Xantrex grid-tie inverters, rather than Fronius (as you mentioned in your first post here). I don't have any experience with Xantrex for grid-tie inverters, we've only ever dealt with their off-grid inverters. That makes it hard to comment.

Other than that, nothing stands out in your configuration. The inverters are not over-panelled, they should have an easy enough time dealing with the panels you have on them.

If your Xantrex inverters fail again I would suggest looking at other brands, and as mentioned we have had excellent experience with Fronius so far.

-RoB-