Had a cold solder joint (I think) on my 24v control board (CB) near the fan end. Flexing the board in that area would cause a loud buzz, very heavy current draw from the batteries then PJ alarm and AC output shutdown. This unit has the new (2015) configuration single toroid. Dr. Powerjack (Helen) sent a new replacement CB, which I installed OK (no thanks to red glue and hot glue globs). The new CB had the two opto-isolators soldered onto the board, incidentally.
I didn't see any obvious bad solder joints on the defective board; but, it's tough to see with this surface mount stuff. Maybe a cracked resistor?
So the issues? The old board (when working) was producing about 233 volts, no load. About 121-0-112. The new board produces 239 volts, 125-0-114.
I've been following the posts re: upward voltage adjustment attempts. I now find it interesting that changing out my CB has affected my output voltages significantly (somewhat to the better?). As nothing else has been changed, it probably can all be attributed to board tolerances, I guess.
I'd like to find a way to balance the split phase outputs to approach 120-0-120. Or at least I'd like to bring down the high side (only) a bit. Instead of adding resistance to the "ladder chain", could I try reducing the overall resistance? This board appears to have two series resistance chains on top and two on the underside -- maybe they all do as part of the H-bridge? Without a schematic or block diagram, I'm shooting in the dark.
Are the resistor chains providing feedback in each leg of the H-bridge? How do I know which chains to modify? Or is the voltage imbalance solely a function of the center tap on the toroid winding (being tapped off center)? Perhaps I should be happy that I have close to the 240 volts that others lust for?
It seems odd that the CB circuit would be dependent on a circuit path that requires megaohms of resistance to control its operation. That just begs problems, seems to me.
I'll finish up with a description of my small solar configuration. I'm using microinverters (4) (APS YC-500A) with eight Solarworld 325W panels. It all seems to play nicely with the PJ 8000 synced. I route excess power to a 24v battery bank and use a Morningstar TS-60 PWM controller/dumper and big power resistors to limit the voltage and protect the batteries.
Each microinverter has dual inputs to separately support two panels. I use a FET in switch mode to remotely switch the solar panel output off/on to each inverter input with a simple 12vdc (gate) signal. A nice benefit of the APS micro (dual input, 250W+250W) is that it needs only one input active to establish sync. The other input can be powered or not, but will instantly add/subtract 250W from the output via my "switch" without forcing a standard five minute restart wait.
I'm working on a automated shutoff/turn on of the solar panels to accommodate changing power demands. This is done via the varying 0-24 vdc output to the dump resistors using a voltage comparator/latching relay circuit. I want to be able to turn off/on some solar panels rather than just heat resistors, in a dynamic environment. So far, it works nicely on the bench. Need a few more pieces to bring it to the real world. Currently, my eight human powered toggles switches do the job, but it takes up a lot of my time . . . . . . .
May have more to share later if anyone is interested. For now, how do I get the high side (only) phase voltage down so I don't have potential issues with the microinverters?