We have a 2014 Georgetown 351ds with dual 15k ac units and a 5500kw generator. When on shore power both ac units operate fine cycle as they are designed and blow cold air. When on generator if both units are running they will run for a short period of time (10-15 min) and then suddenly shut off as if they lost power but the generator does not seem affected…it doesn’t bog down or trip a breaker. Solution is to shut off the ac at the thermostat and then restart and it works fine for a 10-15 min then both shut off again. If we run only one ac unit there is no problem. Will run for days without issue but neither is sufficient to cool the motorhome down. Kind of lost as to what’s happening.

I would start by checking the voltage output of the genset. Check with no load and then with both ACs running. I think you may find that the genset set is not putting out enough voltage. It may need a throttle adjustment. What is exact make and model of genset.

check genny see if both circuit breaker haven't pop reset them both and try them again yours should have 2 on it.

Enablethen is correct. I think you will find that the need exceeds supply. You may be able to turn off some things or run some things on gas which could solve your problem.

bgum wrote:Enablethen is correct. I think you will find that the need exceeds supply. You may be able to turn off some things or run some things on gas which could solve your problem.Exactly. Fridge(5-8amps), Converter (3-5amps), AC (12-16 amps each, and anything else you have going on.....

I refered to low voltage not insufficient amperage(wattage). Low voltage would increase the amerage.

Ac on generator problem. | Good Sam Community

rgatijnet1
Explorer III
Aug 21, 2021
Whether on shore power or generator I always kept one of the Kill-A-Watt meters plugged in to an outlet. These are less than $20 and will give me an instant readout of the exact voltage and the frequency. With both AC's running you can see if your voltage is low or if your frequency has dropped below 60 cycles. Most appliances will operate within a specified voltage range but keep in mind that the lower the voltage, the higher the amperage. You want to try to maintain 120 volts at full load with your generator. Some RV systems also have a type of power control panel that can shed loads(turn off items automatically) during periods that may exceed the capacity of the generator.
gssfc
Explorer
Aug 21, 2021
Voltage is at 120 with load or without. Both legs are the same voltage. This is measured at the transfer switch with no load and again with both ac units running.
gssfc
Explorer
Aug 11, 2021
Thanks for the replies. It’s in Chicago with my girl and I’m in NH. So I can’t test voltage until she returns next week. But I believe you’ve all sent me down the right road. Had to do same thing with generator in my spray foam trailer years ago, unfortunately I forgot about that until now. D’oh!

Thanks for the advice. Tim
theoldwizard1
Explorer II
Aug 11, 2021
The A/C are likely shutting down to overheating. Overheating likely caused by low voltage.

The only way to prove it is a good meter directly connected to the wires at each A/C unit.
enblethen
Nomad
Aug 11, 2021
OP says he has a 5500 genset. If it is a Onan it will produce a little over 45 amps.
It should run everything with no issues if it is running right. It should be running at 2400 RPMs. Lower RPMs will lower voltage and effect the frequency.
Use a digital volt meter to adjust engine speed to produce about 125 volts under no load.
crawford
Explorer
Aug 11, 2021
I have a 5500 genny and can run both 15000 btu ac units my electric rod hot water tank plus both TV's you name it it shouldn't be a problem with that generator.
enblethen
Nomad
Aug 10, 2021
I refered to low voltage not insufficient amperage(wattage). Low voltage would increase the amerage.
jdc1
Explorer II
Aug 10, 2021
bgum wrote:
Enablethen is correct. I think you will find that the need exceeds supply. You may be able to turn off some things or run some things on gas which could solve your problem.

Exactly. Fridge(5-8amps), Converter (3-5amps), AC (12-16 amps each, and anything else you have going on.....
bgum
Explorer
Aug 10, 2021
Enablethen is correct. I think you will find that the need exceeds supply. You may be able to turn off some things or run some things on gas which could solve your problem.
crawford
Explorer
Aug 10, 2021
check genny see if both circuit breaker haven't pop reset them both and try them again yours should have 2 on it.

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Ac on generator problem.

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