My own troubleshooting has led me to "B" being the most likely answer. The big inverter doesn't like it when charging is occurring at 14.7ish volts or higher and gives a fault. Small inverter does not. Big inverter works fine once solar panels are disconnected and battery voltage falls back down to below 14.7ish volts and I cycle power to it.
Both inverters share a 0 gauge wiring connection to the batteries, no socket connections are used and inverters are located right next to each other. Voltage readings have been taken all over the place, including at the battery posts and at the large inverter DC input terminals.
Can a high voltage disconnect setpoint be adjusted?
