AC on 20 AMP Outlet?

[Kimber45]

Any way to tell you are damaging you AC unit from lower power? No thanks. Ill pass

[Jack350]

We visit two state parks each year during our travels. The one we are at now only has a 20 amp service and the other as 30 amp. Both parks have low voltage especially during hot spells. I am in my second day of 90 plus temps and doing well. I do use an autoformer that raises the voltage. We also have a residential fridge running. Things are fine and we use the water heater on gas and do not use the microwave. Current voltage is running between 115 and 121.

[cavie]

Originally Posted by Smiletwice

When you refer to an Electrical Management System, I assume you are referring to the device that plugs in between the power cord and the pedestal. Unfortunately, I have the one that has surge protection and only checks to make sure the wiring is correct. It does not monitor voltage. Is there another way to check the voltage coming in to the AC? I have a multimeter, just not sure where to check in this situation. Also, can the surge protector be attached directly to the adapter and then in to the 20 amp outlet? Thanks.

you can check the voltage for the AC right at the 20 amp breaker in your panel.

[cavie]

Originally Posted by Jack350

We visit two state parks each year during our travels. The one we are at now only has a 20 amp service and the other as 30 amp. Both parks have low voltage especially during hot spells. I am in my second day of 90 plus temps and doing well. I do use an autoformer that raises the voltage. We also have a residential fridge running. Things are fine and we use the water heater on gas and do not use the microwave. Current voltage is running between 115 and 121.

That's good working voltage.

[cavie]

Originally Posted by Smiletwice

Thank you! I'm going to get one of the voltage monitors. So if I've got AC running off 15 or 20 amp outlet (through adapter), and the cord isn't heating up, as long as the voltage meter is showing something between about 105-125 volts, I should be okay?

No K. 105 is too hard on the AC to start especially if the park is full. 110 to 127 is what you want to see. I put a hard start on mine because the voltage was only 108.

[Tacky]

Either I don't worry enough , or others worry too much! I've run 13,500 AC on a 15 amp circuit without any problems. 20 amp should be more than enough. You said your shore power is plugged into an adapter, into the 20 amp outlet, so extension cord won't be an issue. You should be good!

[nrkmann]

AC runs well but starts with difficulty at times on house power. Feel the extension cord at both ends. If it is getting hot you need a heavier guage wire. Remember the lower the number the heavier the wire. So you go to 10 age and it has a 30amp NEMA 5-15 plug that will not plug into a 25 amp house plug. Inside the wall you have 12 guage wire (20 amp rated to a house plug) and it can heat up and start a house fire. Notice if you buy a 10 age extention cord with a house plug it wii say rated for 15 amps not 30 amps. If you are going to do this have an electrician install the proper 30 amp circuit. Better yet put in a 40 amp plug for an electric car charger and use it for both. Use a Kill-O-Watt to check the draw.

[cavie]

Originally Posted by nrkmann

AC runs well but starts with difficulty at times on house power. Feel the extension cord at both ends. If it is getting hot you need a heavier guage wire. Remember the lower the number the heavier the wire. So you go to 10 age and it has a 30amp NEMA 5-15 plug that will not plug into a 25 amp house plug. Inside the wall you have 12 guage wire (25 amp rated to a house plug) and it can heat up and start a house fire. Notice if you buy a 10 age extention cord with a house plug it wii say rated for 15 amps not 30 amps. If you are going to do this have an electrician install the proper 30 amp circuit. Better yet put in a 40 amp plug for an electric car charger and use it for both. Use a Kill-O-Watt to check the draw.

In my 45 years as an electrician, I have never seen a 25 amp house plug. They are 15 and 20. 15 amp plugs are allowed on a 20 amp circuit. Happens in the kitchens/dining rooms. The wire in the walls is romex. 14 and 12 gauge mostly. 14 is good for 15 amps. 12 ga is good for 20 amps. Per the NEC.

[Smiletwice]

Originally Posted by Kimber45

Any way to tell you are damaging you AC unit from lower power? No thanks. Ill pass

So helpful.....not

[Jay2504]

I have a 20 amp /12 gauge wire for just the carport/shed. Runs the trailer AC just fine. The other day I was using a 5hp air compressor, and the ac started running. When the compressor tried to kick on it tripped the breaker. No surprise there, just wasn’t thinking! With the camper AC running I’m at 119-121 volts.jay

[dbledan]

I do exactly what you describe on a regular basis except I also use my EMS. I ran the 20amp connection dedicated outlet (before I had the RV or it would be a 30A) and I can run my 15k btu AC and inverter under 20A. My plug is 45ft from the breaker box on the house and I used the RV power cord and convert to house outlet with a heavy duty adapter. Works great.

A word of caution is to make sure your pins don't get bent on the adaptor and that you have good contact at the outlet. Dont let it hang, support the cord. It will just take a small amount of disconnection for something to melt and start a fire. I learned this the hard way with an electric snow blower and properly sized cords. It pulled 13A and would smoke the connection if it started to come lose.

Sent from my SM-G965U1 using Forest River Forums mobile app

[RZerr]

I run my 13500 BTU AC and fridge plus a few low current lights and devices
AC is about 1550-1700 watts, fridge 350 watts. 20A circuit should handle about 2400 watts. The extension cord gets warm at the plug but not too hot to touch. Has never tripped the breaker.

[Dynamos]

In order to avoid any issues when plugging in at home and running A/C, I had an electrician install a dedicated 30 amp receptacle in the garage. I use a 25 foot 30amp extension cord to reach. Install was under $100.

[catskat]

Originally Posted by HDU

The rule of thumb with electric motor manufacturers is that incoming line voltage can vary + or - 10%. And that doesn't necessarily mean that the motor will fail when ran outside of this tolerance, it does mean that more than likely the motor will not perform to the ratings that are designated on the name plate, and its life expectancy MAY be compromised if used extensively near or outside of the tolerance spectrum.

120v compressors are powered by electric motors. However, not all electric motors are built to the same standards, but most are. Some have less service factor built into them, and these are less tolerant to fluctuations.

My local utility will not guarantee power at less of a tolerance than + or - 10%, meaning that on my 120 volt system, I could see voltages as low as 108v and as high as 132v, and that would be acceptable to the utility company as sufficient supply voltage. Motor manufacturers make their motors with this fluctuation in mind, otherwise there would be failures and warranty claims on most of their products, much of the time.

So I wouldn't worry as much about your breaker ratings (amperage) as being the weak link, I would worry more about the voltage drop realized in your extension cords and connective equipment. If your utility drops the rated voltage by 10 %, and then your extension cords drop it another 5% or more, you could run into some heat building issues with the motor, and horsepower loss as well... and in turn, possible damage to the air conditioner/compressor especially if used like this over a period of time.

Short answer to your question, I use my air conditioner very often at my home on a 15 amp breaker, never have tripped the breaker and the air conditioner runs just fine, but I use a shore power cord as the connecting device which has large gauge wire. If you have a 20 amp breaker circuit, use that one since it should have a larger diameter wire feeding it than the 15 amp does, hence less voltage drop at the outlet if it is a longer run.

everything that hdu says is 100% correct . I have the exact same arrangement at my house. Voltage drop is the only issue, as all the devices will protect each other from over current. Remember, low voltage means higher current, and vise versa.

[Flowers65]

You have a few things to think about running your AC at home . Is the outlet I'm plugging into running other things in my Home , this may drop the voltage down as to what the trailer can use. Second what other things are on in the RV such as converter, Fridge these appliances are pulling power away from the full supply to the AC. The power converter could pull anywhere from 5-7 Amps charging the Battery & the Fridge on Electric could pull 2.5-3 Amps therefore at the Max you could have 10 Amps used out of the 20 Amps. If your plugging in garage you might have lights , Deep freezer plugged into that LINE PULLING CURRENT before the trailer gets any power.