Generator won't Power A/C

[Bob_K]

Specifics:
Class C 2012 Lexington
A/C - Dometic Penguin II with Heat Pump
Generator - Onan RV QG 4000

When trying to start the A/C while under generator power, the generator bogs down and shuts off. The flashing light error code indicates too much load such as trying to run A/C while battery charger is running. I turned the house battery disconnect switch to off and tried again. Fan came on but the compressor won't kick over.

It seems unusual that the installed generator can't pull the load, but it can do everything else but the A/C. Is this normal?

Would a Micro-Air Easy Start be a possible solution?

[A32Deuce]

That does help. Did that mod to mine.

[Steve-W]

Based on the info you provided I would say there is a issue with the generator. Your genny is rated to produce 4000 watts. Your rig being a 30 amp system has a max load of 3600 watts (30 amps @ 120 volts). If your A/C starts on shore power it should start on genny power.

It possible that the genny control is reading a higher peak load due to a internal malfunction. The only way to confirm would be to load test the genny, both continuous and peak. There also is the possibility that the locked rotor current draw from the A/C is excessive (possibly due to a bad start cap) and causing the shutdown. But I would expect that to trip the A/C’s 20 amp circuit breaker.

Also shuting off your battery disconnect may not disable your battery charger. Best bet to remove that load when testing would be to shut off the circuit breaker feeding the converter.

A easy start may help but something else is the root cause.