Help: House Air conditioner not working with generator

[roadmama]

My generator appears to be running fine. All lights on panel light up. Microwave worked. However, when I pressed the AC on it doesn't start. I could change the clock on the thermostat. But no power or fan goes on. I just had my AI checked out by my mechanic who fixed a faulty wire connection from the inverter to house battery which has not been charging it. Mechanic told me that all units such as AC were now working. AI has been plugged in when not in use since batteries were just checked out as fine. What could be the issue?


Sent from my iPad using Airstream Forums

[Protagonist]

The generator only puts out 20amps, not 30amps. And your Energy Management Center sheds loads in a specific sequence when there isn't enough power to go around. If memory serves, the A/C is the first load that is shed.

So my guess is that since the A/C draws 15 amps all by itself, you've got too many other things running that add up to more than 5 amps between them.

When you start up the generator, check the EMS panel in your overhead locker, and if it hasn't automatically switched to 20amp mode, then manually switch it.

Make sure your water heater is in propane mode, not electric, if it's on at all. And turn off everything else except the fridge when starting the A/C, then turn on one item at a time until you find out which load was the straw that broke Onan the Camel's back, i.e. the one that caused the A/C to quit.

[toskeysam]

I once had a similar experience. In my case the AC did not come on for about 60 seconds after I turned it on at the thermostat. I assume there some background "staging" taking place....it did start and ran fine. I also noticed an "hourglass" icon on the thermostat panel. It was there until it started.


Sent from my iPhone using Airstream Forums

[Boxster1971]

The EMS on my 2013 has three modes 30 amp, 20 amp and GEN. So it automatically knows when running on limited Generator power. Yes - AC get shed first and there can be minutes of time delay after turning on the AC before it starts.


- - Mike
2013 Lounge EXT on 2012 Sprinter

[toskeysam]

In retrospect that makes sense.....and I supposedly understood load shedding. Did not pay attention at the time, but I was on 20 amp service, so it would've responded just like the Gen mode. There was a ~12-14DC amp load in the Magnum in Absorb Charge mode at the time. The power mgmt probably held the AC off until the charge current dropped........then again....that was 12 V DC amps......hmmmmmmm


Sent from my iPhone using Airstream Forums

[roadmama]

Thanks everyone for your suggestions. I went out to retry the a/c on generator and it worked.