Run AC on 15 Amp at Home?

[flybouy]

Reading thru the replies there's a lot of "IFs", i(f you leave the following things off, iIF you use a # 12 extension cord, IF the extension cord is short, IF nothing else is plugged into the house circuit, IF, IF, IF..... So I'll add some "WHAT IFs".

What if you're not home and a/c is running and DW or someone else plugs in a vacuum? What if someone turns on the fridge or WH electric by accident? Too many what is that could possibly result in an expensive repair bill. For me, installing a dedicated 30 Amp circuit eliminates a lot of risk. That 30 Amp connection can turn your trailer into a guest house, home office, or a place to "get away" and watch a game.

JMHO, YMMV.

[rlh1957]

If the amperage of the breaker on the outlet the extension cord is plugged into is exceeded it will trip the breaker that is all.
Just like in your house.

The breakers in the RV won’t trip as each was under the breaker amps.

You are good to try it without worry about fire or damage.
You’ll hear if the AC is struggling on startup or breaker in garage/house trips.
If extension cord is hot may indicate a larger gauge is needed.

[sourdough]

Originally Posted by rlh1957

If the amperage of the breaker on the outlet the extension cord is plugged into is exceeded it will trip the breaker that is all.
Just like in your house.

The breakers in the RV won’t trip as each was under the breaker amps.

You are good to try it without worry about fire or damage.
You’ll hear if the AC is struggling on startup or breaker in garage/house trips.
If extension cord is hot may indicate a larger gauge is needed.

The problem with going with an "extension cord" and waiting for it to get hot is....you have to check it constantly. Heat of the day, condition of the air conditioner and RV....all have a hand in how much that A/C runs. If you decide to take a 2 day trip (2 hour) on the wrong day and can't "feel" the extension cord bad things can happen. If you have an extension cord rated for 15A on a 20A circuit you don't need to worry about the home breaker or the trailer breaker, the extension cord just became the fusible link.

[wiredgeorge]

If memory serves an RV A/C will be on a 20A breaker. Already mentioned getting a proper 30A outlet installed so if the OP decides to go the extension cord route, hopefully we won't read a negative follow up.

[LHaven]

Originally Posted by rlh1957

The breakers in the RV won’t trip as each was under the breaker amps.

Mmm, not necessarily. If the voltage on the circuit sags enough, the A/C will compensate by sucking more current, and its individual breaker may in fact pop. It happened here a number of times, most recently just two days ago to both my and my son's RVs when we had a short utility sag.

[PolarisCobra]

I have no intention of leaving the AC on for days, or even many hours, and never unattended. Just want to be able to clean/load the trailer before a trip.

I get that it is not a perfect situation, just short term. Will likely add a 30 A plug in the spring. Also need to add wiring (proper setup) for an emergency generator, may have electrician do both in one visit.

We understand that all other appliances stay off, nothing gets plugged in. If we want to vacuum, the vacuum cleaner will be connected to a cord of it's own, on a separate circuit.

[wiredgeorge]

Originally Posted by PolarisCobra

I have no intention of leaving the AC on for days, or even many hours, and never unattended. Just want to be able to clean/load the trailer before a trip.

I get that it is not a perfect situation, just short term. Will likely add a 30 A plug in the spring. Also need to add wiring (proper setup) for an emergency generator, may have electrician do both in one visit.

We understand that all other appliances stay off, nothing gets plugged in. If we want to vacuum, the vacuum cleaner will be connected to a cord of it's own, on a separate circuit.

I have a WEN 6250W inverter generator which is too bulky for taking along for RV use. It does have a 30A RV plug. I have an adapter for the cord to plug into a 30A receptacle on the outside of my home and the generator stays plugged in when not in use. I had an electrician install a transfer switch adjacent to my 200A service box inside my home and wire in the transfer switch. There are so many wires that doing it myself wasn't an option. I can switch over by circuit and almost my whole house with electricity in the event of a power outage. Only things that are not powered are the electric stove, one 220V mini-split, microwave, furnace/air conditioner and well pump. I would love to have a whole house system like a Generac but they are too costly for the limited use we might have.

This gizmo is similar to what we use to transfer power from the grid to generator:

https://www.maxtool.com/products/rel...Tool+PLAs+6-20

[PolarisCobra]

Originally Posted by wiredgeorge

I have a WEN 6250W inverter generator which is too bulky for taking along for RV use. It does have a 30A RV plug. I have an adapter for the cord to plug into a 30A receptacle on the outside of my home and the generator stays plugged in when not in use. I had an electrician install a transfer switch adjacent to my 200A service box inside my home and wire in the transfer switch. There are so many wires that doing it myself wasn't an option. I can switch over by circuit and almost my whole house with electricity in the event of a power outage. Only things that are not powered are the electric stove, one 220V mini-split, microwave, furnace/air conditioner and well pump. I would love to have a whole house system like a Generac but they are too costly for the limited use we might have.

This gizmo is similar to what we use to transfer power from the grid to generator:

https://www.maxtool.com/products/rel...Tool+PLAs+6-20

That is the sort of setup I am thinking about for the generator. Really a separate issue from the trailer, and if there was a power outage, the trailer would not be powered by the generator, and the outside plug would not be powered by the generator.

May have the electrician install both the trailer 30A plug, and the generator/transfer switch wiring just because it will be a bit less expensive if he does it on one trip. Not really an issue at this point, don't have a generator yet anyway.

[wiredgeorge]

Originally Posted by PolarisCobra

That is the sort of setup I am thinking about for the generator. Really a separate issue from the trailer, and if there was a power outage, the trailer would not be powered by the generator, and the outside plug would not be powered by the generator.

May have the electrician install both the trailer 30A plug, and the generator/transfer switch wiring just because it will be a bit less expensive if he does it on one trip. Not really an issue at this point, don't have a generator yet anyway.

I have two 30A services with RV plugs on the property and wired both myself. They are on the pole where my outside boxes are so there wasn't a lot of expense as far as wire goes. I wouldn't install a transfer switch because of complexity. I am sure some of the folks on this site wouldn't hesitate but I felt it was beyond me.

[TXiceman]

We have been running the one Coleman Mach 15,000 BTUH for 2 days from the garage 20-amp breaker with the RV cord adapted to a 120-volt adapter. Nothing else is on this circuit except for the sprinkler controller. The A/C does not have a soft start kit but will as soon as the weather cools down. The fridge is a 12-volt Furrion and the RV has two 200-Watt solar panels with two 100 amp-hour Lithium batteries and a tankless water heater.

All you have to do is watch what else is on the circuit and teach others in the house about the "what-ifs" and the consequences. People are smarter than dogs and can be taught.

Ken

[PolarisCobra]

Originally Posted by wiredgeorge

I have two 30A services with RV plugs on the property and wired both myself. They are on the pole where my outside boxes are so there wasn't a lot of expense as far as wire goes. I wouldn't install a transfer switch because of complexity. I am sure some of the folks on this site wouldn't hesitate but I felt it was beyond me.

Are you saying that you plug your generator into one of those 30A plugs, and back feed into the house?

Please understand that is a very dangerous practice. Done incorrectly, you can easily feed power out to the grid. A line worker who is expecting a line to be dead can touch the wrong thing, and be killed. You may know how to do this without back feeding, but if you are ever away from home, and the power goes out, a well meaning family member can get someone killed.

My brother-in-law, son-in-law and nephew are all National Grid linemen. For their sake, please do not ever back feed from a generator into your house without a properly wired transfer switch.