[RE-wrenches] Enphase / Inverter failures

[William Miller]

BobO:

I too was hesitant to install micro inverters for the reasons you 
cite:  why should I have to go on a roof to replace electronics? and, 
should electronic components even be on a roof?

I am converted.  We have had a few failures, but a manageable 
percentage.  It does suck to go on the roof and to require two people in 
most cases, to replace an inverter, but we have managed.  I get $150.00 per 
inverter.  Not great, but better than nothing.   I add a few dollars to 
each Enphase install to build up a fund that, added to the manufacturer's 
reimbursement, covers my costs.  Consider this:  to replace most 5Kw or 
above inverters requires two people anyway because of the weight of the 
inverter.  Furthermore, when a 5kw inverter fails you've got to get out 
there, stat, but when a 215 watt inverter fails, you can put it on your 
schedule for when you are next in the neighborhood.

I don't enjoy the PLC interference problems, which are rare. When they have 
occurred, Enphase provided continuous technical support, including factory 
evaluation of line filters and enhanced system analysis.  Did you know that 
each Enphase system has a built in spectrum analyzer? Tech support can 
provide a printout of interfering signals to help in 
troubleshooting.  Installing a separate AC load center to accept the AC 
return breakers helps with solving these problems.  I understand that the 
next release of Enphase inverters will be Wi-fi, eliminating the PLC 
protocol entirely.  When the communication works, (which it does most of 
the time) it is a very valuable resource.

Micro inverters have added a degree of flexibility in system design 
hitherto unavailable:  The Enphase has allowed us to retrofit a few older 
GTBB installations, for example tieing two SR100 modules to one M190 
inverter.  We have also added a few micro inverters to string inverter 
systems that needed a few more watts but had no room for expansion either 
in existing strings into existing inverters, or no room on any wall for 
more string inverters.

I would encourage you to try an Enphase installation.  I have nothing to 
gain for saying that, I just like the product and I want my fellow wrenches 
to have all the resources to provide the best design for a given challenge.

We installed Fronius for awhile, but we had a greater than 300% failure 
rate (not a typo, every inverter failed at least 3 times).  There is not 
enough reimbursement in the world to compensate for that failure 
rate.  Most Fronius employees have been great to work with but two of them 
defamed me to an important client, and that has left me feeling less than 
supportive about Fronius.

I am curious, what is your failure rate with Fronius inverters?  What 
climactic environment are you in?  Do you have coastal influences?

Sincerely,

William Miller

At 01:21 PM 5/7/2013, you wrote:
>I'm one of the many installers who still won't touch a micro yet. It's not 
>so much that there were failures early on, it's how companies like Enphase 
>HANDLED them. My understanding is that you basically got a replacement 
>inverter and got stuffed for your time and travel.