Running single rig AC unit on a 20amp circuit.

[Geocritter]

My RV is a 1994 33' Holiday Rambler. I have a question about running my rigs AC (single unit only). It’s been hot here in the Crater Lake area and I’d like to run my AC, my concern is that my 30amp service is hooked up to 20amp service via a 20/30amp adapter. Right now the only things I have that need power are my small electric refrigerator (it’s not an elec/propane unit) and my electric hot water heater. The other things are my laptop, additional flat screen monitor, and an inkjet scanner/printer.

Could I damage my single AC unit running it through a 20amp service with the load I’m running? The 30amp service I’ve had in the past has always handled it just fine. This is important and more than a simple comfort issue. I’m semi-retired and just received a large research/writing project with a very short deadline. It’s just too hard to work and think in this afternoon heat.

Thanks in advance for any insight y’all can give me regarding this issue.

Steve

[navegator]

Turn off all electical apliances, refrigerator, water heater, and the battery changer/inverter if you have one and only use the air conditioner and the laptop and monitor the temperature of the 20/30 adapter by touching it every half an hour or sooner.

The adapter is going to feel warm if the temperature goes higher you have a problem with the adapter, stop using it and look for melted or deformed "plastic" on the pedestall or house outlet, the adapter and the plug from the RV cable, also check futher down the cord for heat and or deformed sheathing.

If there is any melting or defority any where STOP immediatly and rectify the situation, you do not want an electrical fire, you can also go to a libary or center where there is air/con and an outlet.

navegator

[square_dancers]

In my view you should invest in a generator. Then all you need to do is buy gas. You should get about 12 hours of run time per tank.
Can't do that? Run your water heater on propane or turn off your water heater unless you want to bathe.
Do you use a microwave? Would think that using that would really draw all your load away from everything else.
Low voltage will damage your computer, printer, and flat screen. Over time and continuous low voltage will damage and shorten the life of your AC compressor unit, if it is the original unit it's already 10 years old and typically near the end of it's life cycle if you have used it very much over the 10 years and have not preformed proper preventive maintenance.
You can always use a good quality extension cord and power up your electronic devises that way.
Your RV is not built to NEC code requirements, that's why RV builders can use under sized wiring in RVs.

[ScottG]

Water-Bug wrote:

ScottG wrote:

Water-Bug wrote:
First thing to do is check the current draw of your AC. There should be a manufacturers tag giving the model number and electrical requirements. Second, the electric water heater is probably drawing nearly all the current availale, when it is heating water. Cycling between water heater and AC may be necessary to prevent overloading the circuit. Third, although most home wall sockets are wired to 20 amp breakers, the wall sockets themselves are only rated at 15 amps. True 20 amp sockets will usually have a pin that is verticle to and connected to the + . ( two parallel pins for + and neutral, with a round ground pin below and a pin verticle to the + pin.)

I used to think those outlets were better as well but during a conversation I had with a Litton rep I found out the internals of both 15 and 20 amp outlets are identical other than the shape. He went on to clarify that the 15's will carry current just as well as the 20's.

The internals may be the same for ONE manufacturer but maybe not all. The specs are the specs. Never exceed the spec'd current for the receptical.

No I suspect they're all that way since NEC allows us to use 15A outlets on 20A circuits.

[Water-Bug]

ScottG wrote:

Water-Bug wrote:
First thing to do is check the current draw of your AC. There should be a manufacturers tag giving the model number and electrical requirements. Second, the electric water heater is probably drawing nearly all the current availale, when it is heating water. Cycling between water heater and AC may be necessary to prevent overloading the circuit. Third, although most home wall sockets are wired to 20 amp breakers, the wall sockets themselves are only rated at 15 amps. True 20 amp sockets will usually have a pin that is verticle to and connected to the + . ( two parallel pins for + and neutral, with a round ground pin below and a pin verticle to the + pin.)

I used to think those outlets were better as well but during a conversation I had with a Litton rep I found out the internals of both 15 and 20 amp outlets are identical other than the shape. He went on to clarify that the 15's will carry current just as well as the 20's.

The internals may be the same for ONE manufacturer but maybe not all. The specs are the specs. Never exceed the spec'd current for the receptical.

[camper19709]

Yes you can run the a/c on 20amp but you will need to turn the a/c off when you turn the water on. Once the water is hot turn it off and turn the a/c back on. That should prevent circuit overload and the adapter getting hot.

[ScottG]

Water-Bug wrote:
First thing to do is check the current draw of your AC. There should be a manufacturers tag giving the model number and electrical requirements. Second, the electric water heater is probably drawing nearly all the current availale, when it is heating water. Cycling between water heater and AC may be necessary to prevent overloading the circuit. Third, although most home wall sockets are wired to 20 amp breakers, the wall sockets themselves are only rated at 15 amps. True 20 amp sockets will usually have a pin that is verticle to and connected to the + . ( two parallel pins for + and neutral, with a round ground pin below and a pin verticle to the + pin.)

I used to think those outlets were better as well but during a conversation I had with a Litton rep I found out the internals of both 15 and 20 amp outlets are identical other than the shape. He went on to clarify that the 15's will carry current just as well as the 20's.

[Water-Bug]

First thing to do is check the current draw of your AC. There should be a manufacturers tag giving the model number and electrical requirements. Second, the electric water heater is probably drawing nearly all the current availale, when it is heating water. Cycling between water heater and AC may be necessary to prevent overloading the circuit. Third, although most home wall sockets are wired to 20 amp breakers, the wall sockets themselves are only rated at 15 amps. True 20 amp sockets will usually have a pin that is verticle to and connected to the + . ( two parallel pins for + and neutral, with a round ground pin below and a pin verticle to the + pin.)

[ScottG]

Your probably close with all that other stuff running. You need to monitor the voltage to make sure it doesn't drop too low.

[john_bet]

One word answer is no. A/c only, no heater,no frog. Then keep an eye on the adapter as it may get warm. A 20 amp circuit should only be loaded to about 16amps for continouse use.