dual AC on 30 amps - I think I made it work
Here is what I did. Middle of day once temperatures start heating up, I switched my water heater and refrigerator over to propane. I unplugged cofee pot, curling iron, and anything else drawing elec...
Forum Discussion
Not recommended to run 2 ACs on 30 amps. Some will do it and claim it works just fine, but...
The momentary starting current of AC units is 50-60 amps and that will be on top of an already running AC unit and any other loads. The 80 or so amps can really drag down the voltage and an AC can struggle to start. It causes the motor windings to overheat and will cause damage. You may find you can get 2 ACs to start but the damage is cumulative and you can have an AC unit prematurely fail one day for no apparent reason. AC units are not cheap to replace...
Running AC units on chronically low voltage (at full load) is also not good when it gets down towards 105 volts. Yes, the current draw does go up somewhat too at lower voltage, although I've never been able to find data on RV units. A compressor load remains the same but as voltage goes down, a motor will generate less power and will work harder to keep the compressor going and draw more current. Again, the excessive current will cause damage to AC motors.
It's always a good idea to monitor your voltage in a CG. Newer CGs usually have decent voltage depending on where you are on a run of pedestals and if everyone else isn't running AC units. Older CGs can have high voltage drops and some sites can have long individual runs of smaller gauge wire to them which can worsen voltage drop.
A few folks have connected a 2nd AC to the 20 amp receptacle in a pedestal. But that can also be a voltage drop problem because the electrical code doesn't require wiring to pedestals to be sized for a 30 & 20 amp recept. to be running together at the same time.
If you still decide to run 2 AC units on 30 amps, I'd at least plug into a 50 amp pedestal using an adapter, *if* you can find a 50 amp pedestal (often hard to find one).
The momentary starting current of AC units is 50-60 amps and that will be on top of an already running AC unit and any other loads. The 80 or so amps can really drag down the voltage and an AC can struggle to start. It causes the motor windings to overheat and will cause damage. You may find you can get 2 ACs to start but the damage is cumulative and you can have an AC unit prematurely fail one day for no apparent reason. AC units are not cheap to replace...
Running AC units on chronically low voltage (at full load) is also not good when it gets down towards 105 volts. Yes, the current draw does go up somewhat too at lower voltage, although I've never been able to find data on RV units. A compressor load remains the same but as voltage goes down, a motor will generate less power and will work harder to keep the compressor going and draw more current. Again, the excessive current will cause damage to AC motors.
It's always a good idea to monitor your voltage in a CG. Newer CGs usually have decent voltage depending on where you are on a run of pedestals and if everyone else isn't running AC units. Older CGs can have high voltage drops and some sites can have long individual runs of smaller gauge wire to them which can worsen voltage drop.
A few folks have connected a 2nd AC to the 20 amp receptacle in a pedestal. But that can also be a voltage drop problem because the electrical code doesn't require wiring to pedestals to be sized for a 30 & 20 amp recept. to be running together at the same time.
If you still decide to run 2 AC units on 30 amps, I'd at least plug into a 50 amp pedestal using an adapter, *if* you can find a 50 amp pedestal (often hard to find one).
