After 3 days of rain the sun came out briefly today, so I went over to see if my 3 day old system was generating more than 25 watts, only to find the red LED on, and a message complaining about the GFDI fuse. Now the guy who came out for the final inspection said something about this type of thing being common in the first week or so of operation, and described a secret handshake necessary to reset the inverter, but of course I wasn't paying enough attention at the time. Is this really a common problem? and if so, what is the secret handshake?

I went through the "commissioning" flowchart in the manual (Sunny Boy 2500U, btw), but the red light stays on solid, which seems to point to a real blown fuse?

Any help/pointers greatly appreciated. I'm already depressed that the state took all summer to approve my rebate, so the system didn't get turned on until December, but this is too much...

One of the things I didn't like about the sunnyboy durring my testing was the startup test requiring removing the gfi fuse , killing the power and then re-installing the fuse.

I suspect that this "commissioning" wasn't done correctly and your unit has never been producing power.

The sma manual spells out the steps but it is simply this.

Start with DC diconnect open (no power)
1)
Pull the fuse , apply power (close disconnect), watch the lights dance for a minute

2)
open disconnect , wait until all the lights are out (can take upto 5 minutes !!) then install fuse and once again apply DC (close disconnect)

Unit Should power up correctly.

This is a requirement to verify that the sunnyboy can "detect" a ground fault condition.

The Suntie doesn't need this since it has a real GFI breaker , unlike the Sunnyboy , which has a fuse

If the steps don't help , get a ohm meter and check the fuse itself , if open , replace.

But my guess is it was never done right the first time

In this case it was the fuse that was bad. Now we're on to problem #2, "overcurrent" failure. The Tech is going to come out tomorrow to look at this one :-(

Thanks for the update .... Lets us know what is finally is ...