I recently installed a 12/3000/120-50 230V Multiplus on my boat. Shore power is supplied through a 3600W isolation transformer to the Multiplus. For loads, I have house outlets and a small aircon unit (~5amps) connected to AC-1, and water heaters and a larger aircon (~7.5 amps) are on AC-2.
This past weekend, while connected to shore power and running just the two aircon units, the Multiplus shut down on Inverter Overload. Does this make sense? I’m obviously well within the capacity of the 50 amp transfer switch, even considering startup current for the aircon compressors. Any ideas what might be the cause of this, and how I can rectify it?
Additional background in case it matters: I’m presently in the US, and since the isolation transformer boosts the shore power voltage slightly, the input to the Multiplus is about 259 volts @ 60hz. Both air conditioners are nameplate 230V / 60hz units. Prior to installing and connecting the smaller aircon unit on AC-1, I was able to run the large aircon unit, plus water heaters (all on AC-2) without a problem.
Thanks in advance for your time and advice!
Jeff