MNRon, I was looking at your other thread and noticed this.
"With that said, I tried it two or three times and got similar results: arc50 shows +30A or so charging batteries from generator; AC turned on and current swings momentarily to -400A 12v current or so, oscillates briefly then 3012 kicks generator out and settles down to -180A (had some lights and other things on) running AC fine; after little bit 3012 tries to bring generator back in (still running) and current jumps back up to -400A range again. After a few sequences watching this oscillatory behavior I chose to run AC off of batteries alone for an hour or so (it was HOT out) but didn’t want to subject my AC to any further experimentation."
When your trying to start/ run your A/C are you allowing the Magnum to charge your batteries at the same time? If so have you tried the A/C with the charger turned off and if so is it faulting off also?
When I use my generator I do not allow the Magnum to charge from the inverter/ charger while using the A/C. You know it takes maybe a minute +/- or so for the Magnum to sync with the generator when it excepts the generator turn off the charger and see if you still have issues...if you haven't tried this already. ;)