Posted 2013-08-24 5:27 PM (#154237) Subject: AC with 20amp service
Veteran
Posts: 218 Location: Ohio
I need to know if using the AC on vent only, not running the compressor, will be OK on a 20amp service. We will be going to our families farm over labor day weekend. We will run the AC during the day on the generator but at night I would just like to use the vent to circulate the outside air. We can use the farm electric but it is not a 30amp circuit. I know if you run the AC normally on 20amps it will damage the unit, is that true for the vent fan as well?
Posted 2013-08-24 7:44 PM (#154240 - in reply to #154237) Subject: RE: AC with 20amp service
Expert
Posts: 2958 Location: North Carolina
The fan by itself draws only a fraction of the compressor. If you have a 20 amp service, it should be enough to run the compressor too IFthe wire was sized correctly for the length of run.
Posted 2013-08-24 7:50 PM (#154241 - in reply to #154237) Subject: RE: AC with 20amp service
Expert
Posts: 2958 Location: North Carolina
System won't allow more than a few edits ..
Continued from above ... The best way to check this is to get a digital volt meter. Connect the meter leads to the power line. With the a/c compressor running, the voltage should be at least 115 volts. If less... The wire is too small for the run. and will damage the compressor.
Do this same test for the fan only. 115 volts while only fan is running is okay.
Posted 2013-08-27 9:41 AM (#154321 - in reply to #154237) Subject: RE: AC with 20amp service
Expert
Posts: 5870 Location: western PA
As was stated, many AC units are run on 20 amp circuits. This also takes into account the higher start up amps needed, especially during hot weather. Our electrical panels are rated at 30 amps, with 20 of that intended for the AC units. The running amps are less than the starting 20 amps or more, and none of our AC units have been damaged in any way over many years, with their continual usage of those circuits.
The fans of our AC units are 1/5 HP and only use a couple of amps to run. There is no problem using them continually with a 20 amp circuit.
Posted 2013-08-27 9:47 AM (#154322 - in reply to #154237) Subject: RE: AC with 20amp service
Veteran
Posts: 259 Location: Topeka Ks
You should be okay running you A/C on a 20 amp circuit. You will not be able to use the microwave or coffeemaker. Also you have to plug the shoreline into the outlet. You will using all of the 20 amps.
Posted 2013-08-27 9:52 AM (#154323 - in reply to #154321) Subject: RE: AC with 20amp service
Expert
Posts: 5870 Location: western PA
Most of the shows we frequent only have 20 amp services available. This necessitates using an adapter from our 30 amp shore cord to a 20 amp source. The AC units operate normally, but before we initiate a start up, we have to make sure other electrical loads are off. The initial surge combined with the other loads, can overload the available 20 amp shore power. Once the AC unit has been running, other light amperage draw AC accessories can be used. IE: you cannot combine the AC with a microwave, electric coffee pot, hair dryer etc.
AC with 20amp service
