vac-bfr error on Sunny Boy 1800U Inverter

PBRhino

The system was installed in July of 2007.
I have 16, 300W solar panels in two rows.
Each row of 8 has its own Sunny Boy 1800 Inverter tied to the grid.
One of the inverters is working as it should.
The second one is not.
This morning it initially gave me an error of K1 Open.
I rebooted a couple of times turning off AC side and then DC side.
Still had K1 Open error.
Then I examined the fuze and did a continuity check on it. 
Meter read 0 indicating fuze is ok.
When I reconnected the fuze, it gave me the VAC Bfr error
Next I checked to ensure each panel was okay.
Each one read between 26 and 28V DC
I then took the cover off and measured the AC voltage between the red wire and the neutral wire. It was 116V.
I then did the same for the red and ground wires which also read 116V
I have chekced all connections.
Is there anything else I can do?
Or, is it time for a new inverter?
Thanks for your time and help!

PBRhino

Correction, the panels are 190 Watts each.

Estragon

It may be time for a new inverter.  Apparently, the k1 error is some sort of too-high voltage lockout.  If it happens too many times, the relay connecting to grid is locked open.  With it locked open, presumably the second error is thrown by frequency being out of spec (which it would be, with the relay open).  The high voltage may have happened overnight (when grid usage is low) and appeared ok in the morning.  High voltage could do lots of mischief in the inverter, breaking down insulation and such.

Keep in mind this is purely speculation, but if this theory is correct, the other inverter may not be far behind the first in throwing the error.  There may be a way of clearing the error, but this would likely be a very temporary and possibly dangerous fix.

PBRhino

Thanks, 
Any suggestions on grid tie in inverters?

Estragon

I'll leave it to others here with more grid-tied experience to offer suggestions.