clyde wrote:
I have 18 Sharp 208's connected 2 strings of 9 homerun to xantrex gt 3.8 about 18 feet of equal length.
-snip-
Thanks
Clyde
Huh, I have Sharp 208's also, 22 of them, 2 strings of 11.
That usually gives me (after all the start-up dithering while my panels are lit by ambient light, no direct sun) :
VDC DC Amps MPPT DC Pwr AC Pwr Eff
310.1 1.35 310.4 423 421 99.53
and thru the rest of the day, voltage stays the same (give or take a couple of volts), and the current climbs up, then down, till sunset & shutdown. I've seen only a couple of times, an offline indicator on the GTview, but it seems to not show as a gap in my log files.
The oddness of your voltages (which I'd expect your power production voltages to be about 48V lower than mine) Maybe 9 panels are below what reliable start-up voltage is ?
GT sizer tool :
http://www.xantrex.com/support/gtsizing ... p?lang=eng
suggests 9 modules, if they are on a hot sunny roof, are just barely at the mininum voltage. [ 202VDC output, 195V min input voltage ] Add some wire losses, and you have a mess.
Maybe a bad connection under load, on a MC connector that didn't get fully engaged ?
I had one bad panel with an odd brown spot on it, have you checked your panels visually ?
You can use the DC disconnect on the bottom of the GT, to kill the power, then you can connect/disconnect wires without arc welding them, but they still have 300V @8A in them ready to bite your skin. Maybe there is a bad wire in the conduit runs, try grabbing a spare hunk of 30' os so, and try a new wire run.