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Topic: RV Electrical Extension Cord to run AC

Posted By: malibuman on 07/10/11 08:54pm

I park my RV in my driveway and would like to run the AC sometimes.
I can plug the RV into my home's clothes dryer outlet (30 amp) but will need an extension cord. Does anybody know the maximum length my extension cord can be? Thanks!

Posted By: bldrbuck on 07/10/11 09:05pm

Your AC will need about 15 amps. 14 guage wire is rated at 15 amps but that is too small for your use. 12 gauge is rated at 20 amps, That should be good for 25 feet. Beyond that You should use 10 guage,

Posted By: Alfred622 on 07/10/11 09:07pm

I don't know if this will work for you, but I can run my AC in my motorhome on a 20 amp circuit... I've had a 50' extension cord (I think it was 10 ga) between my motorhome and a house 110v socket and it all worked just fine. I've also gotten the MH close to my garage and run the 30amp cord from the MH to an outside electrical socket and with a 20a to 30a converter, used that to drive my AC also.

I guess a lot depends upon the electrical needs of your AC.

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Posted By: B.O. Plenty on 07/10/11 09:12pm

That 30 amp dryer outlet is 220 volts. Chances are your trailer is 110 volts. Make sure you have the right hook-up..


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Posted By: bobu on 07/10/11 09:11pm

Your dryer is 30 amp 220 volts. DO NOT USE THAT !! RV's are 30 amp 110 volts

Posted By: malibuman on 07/10/11 09:10pm

Thanks for your reply.
To clarify...

I can run my AC with a 100 ft. 10 guage extension cord plugged into a 15 amp outlet?

Posted By: malibuman on 07/10/11 09:16pm

Can I use a 10 guage extension cord (50-75 ft.) and plug into a regular household outlet with a converter (30 amp to reg. household type outlet)? Thanks again for the replys.

Posted By: Wayne Dohnal on 07/10/11 09:19pm


Your dryer is 30 amp 220 volts. DO NOT USE THAT !! RV's are 30 amp 110 volts

If you have the right kind of dryer outlet this could be done with the proper adapter. Since the original post didn't mention the outlet type I'm fearing that you're not aware of the issues. Using the wrong outlet or hooking up incorrectly with the right outlet will smoke a bunch of things in the RV.

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Posted By: AllegroD on 07/10/11 09:30pm

malibuman wrote:

Can I use a 10 guage extension cord (50-75 ft.) and plug into a regular household outlet with a converter (30 amp to reg. household type outlet)? Thanks again for the replys.

Yes. Only issue might be if that outlet is on a ganged circuit. If the circuit breaks, check to see if there is a freezer (or other item) on the circuit.

Posted By: mena661 on 07/10/11 09:40pm

malibuman wrote:

Can I use a 10 guage extension cord (50-75 ft.) and plug into a regular household outlet with a converter (30 amp to reg. household type outlet)? Thanks again for the replys.
I have 30A trailer. A/C doesn't work at all on a regular house outlet. If you have a 20A outlet, try that.

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Posted By: n8wgb on 07/10/11 09:55pm

I plug into a regular household plug in my garage. It has 12 guage wire going to it, and I use an adapter to go from the 15A to 30A plug from the camper. The breaker on that circuit is a 20A. It does run my AC, but not a lot else. If I was using an extension cord, it would be at least 12 guage. 10 would be better. Nice when I'm working on something in hot weather.

Do NOT try to tie into the dryer circuit. As said, it is 220v, not 120...


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Posted By: dougrainer on 07/11/11 05:57am

Can you do what everyone is suggesting? YES. IS IT SAFE? NO. The MINIMUM breaker IN your RV for a RV roof AC is 20 amp. The 3 prong outlet in ANY receptacle is rated at 15 amp MAX. Running an extension cord will increase your hazard. So, it is NOT safe to do what you want to do. After you have done it (you will because these people have told you you can), look at the 30 to 15 adapter and the prongs on your cord ends. You will see they have been hot and will be pitted. Ask yourself WHY that is. Because you are overloading the circuit. Doug

Posted By: j-d on 07/11/11 07:31am

30A from one leg of the dryer outlet should power the coach at 30A but it wouldn't be "code" to do it that way.
That extension cord sounds heavy, but check a chart for what it takes to go One Hundred Feet. I think you'll have too much loss.
We had a 20A outlet on the outside garage wall where we parked the first coach. Its 13500 AC would melt the 20-to-30 adapter plugs, but not trip the breaker.

If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB

Posted By: RoyB on 07/11/11 09:50am

I run my 30AMP POPUP Trailers off of a HD 10GA 100-foot long extension cord plugged into the garage 120VAC 15A receptacle. I use a RV30A-15A 18-long adapter cord (Walmart) on the end of the extension cord where the trailer shore power cable plugs into it. Nothing gets warm to touch. I sometimes will trip my garage breaker if I have the air conditoner on and start up the microwave... Installing a pedstal is the best idea but it will work from a HD extension cord. Been doing it here for five years now...

I also do the same thing for my fifth wheel 30A trailer except I use two 50-foot RV M-F extension cables followed by a 25-foot HD 10GA extension cord plugged into a 20A circuit in the garage with same results as above. I used to have three 50-foot RV extensions cords in place but wife recently ran over one with the riding lawnmower.

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Posted By: wa8yxm on 07/11/11 12:55pm

Hardly a week goes by that someone does not post about plugging into a dryer or welder/Air compressor outlet and .... Blowing nearly all the electronics in their RV to bits.


You, beat them in the IQ department by asking first.

Now, have an electrican who knows RV's put in a proper TT-30 outlet, Then, using a volt meter Even a low cost plug in job such as the Kill-a-watt in volt meter mode with an outlet adapter from your local RV supply (So you can plug the 15 amp meter into the 30 amp outlet) verify it's 120 volt (110-120) and not 240 volt.. Even before you do that make sure that outlet has a SINGLE circuit breaker, not a dual ganged breaker, THEN, and only THEN plug in.

Once you have verified it's a good TT-30 make a label, Use a laser printer and Avery Waterproof peal and stick

Travel Trailer
30 amp Outlet
120 VAC
Do not use for
240 volt devices.

ANd paste it next to the outlet.

Home is where I park it.
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