Community Forums

Rjhuser · 05-10-2012, 09:33 PM

It can be done IF it is 4-wire receptical BUT you really need to know what you are doing.

You would be using one side of the breaker, and yes it would be protected - a double pole breaker will trip if the phase to neutral exceeds the breaker rating. In that aspect you are lucky as a dryer breaker is a 30 amp breaker.

A special adapter would have to be made - you would need a 4-blade dryer plug, a RV 30 amp receptical "NEMA TT-30R" and a length of 10/2 (with ground) SOOW cord. At the dryer plug end, the green wire would go to the ground lug, the white wire (the neutral) would go to the "W" lug, and the black wire to either the "X" or "Y" lug. The other lug would be unused.

On the RV receptical side, again the green wire to the ground lug, white wire to the "W" lug, and the black wire to the "B" lug.

Before using the adapter CHECK THE VOLTAGE WITH A MULTMETER FIRST!!!

Again, you should only try this if you are comfortable working on electrical equipment. I DO NOT recommend trying this modification by a novice or someone not used to doing electrical wiring.

(By the way, I did something similar to this to allow my TT to be connected to my generator. I purchased a 50 amp to 30 amp adapter, cut the 50 amp plug off, and installed a twist-lock plug I needed to connect to my generator.)

Rick

wa8yxm · 05-11-2012, 07:16 AM

Two answers: IF the dryer plug is a 3-wire job (Common on older houses) DO NOT DO IT, there is no way to do it safely.

If the dryer is a 4-wire plug, then you need to use a voltmeter to make sure but normally the "Odd shaped" pin is safety ground.

Get a new dryer cord from the hardware store. and a box and a TT-30 outlet (or better yet a 50 amp outlet, future upgrade dont' you know)

Safety ground to safety ground (GREEN wire/Screw)
White wire to the silverly screw This should be the pin opposite the ground. on a 4 wire plug/outlet but again CONFIRM. should show zero volts when measured to ground.

TT-30, One of the remaining wires to copper color screw tape the other.

50 amp One of the remaining wires to EACH of the other screws. (one each)

Then use the proper dogbone for your rig.

Dogpatch · 05-11-2012, 07:35 AM

I would just call an electrician. I respect that many will know and advise a way to do it, (thanks to all contributors) however, the liability lies with the student and non of the teachers.
At work, we always have electricians make up power boxes for us to be able to plug our equipment into either dryer or stove plugs. They use the proper plug for 220V wall outlet, and run it into a box wired appropriately for what ever type of connection we need. This could be done as a portable which you could take to anyones house and stay.

Better to be safe than sorry.

In my opinion, this is not an area you want to try to save a few dollars as a DIY project. The consequences are too costly.

bonzocfi · 05-11-2012, 07:36 AM

monkey....I made a cable to do just what you want. I don't need it any longer as I had an electrician wire 50A service in my garage. PM me if you're interested.

mgscott4 · 05-11-2012, 03:28 PM

If your just trying to run one AC buy the shortest 10 awg extension cord needed and use your 30 amp cord first then the a 20 amp adapter, then the 10 awg extension cord,and you should be able to plug into a household recepticle and not trip the circuit as long you are the only one on that circuit. If there is a lamp, tv, or any other device using the same circuit, you will probably trip the breaker.

I can do this at my house.

Dogpatch · 05-11-2012, 06:45 PM

Quote:

Originally Posted by mgscott4

If your just trying to run one AC buy the shortest 10 awg extension cord needed and use your 30 amp cord first then the a 20 amp adapter, then the 10 awg extension cord,and you should be able to plug into a household recepticle and not trip the circuit as long you are the only one on that circuit. If there is a lamp, tv, or any other device using the same circuit, you will probably trip the breaker.

I can do this at my house.

Won't work I don't think. Poster would like to use at least 1 AC and plug in to use RV amenities. Needs 30 amp.

LadyFitz... · 05-11-2012, 07:10 PM

Quote:

Originally Posted by cnkinthebus

...It can be done...

NO! It cannot be done! A 220v dryer outlet has two legs that have 220v across them and a ground. A 30A RV connection requires one 120v leg, a ground, and a neutral. The dryer outlet lacks the neutral.

LadyFitz... · 05-11-2012, 07:11 PM

Quote:

Originally Posted by JimM68

...The 30 amp dryer plug is 2 hots and a neutral...

Actually, it has two hots and a ground.

TXiceman · 05-11-2012, 07:58 PM

A 50 amp dryer plug has 3 flat blades and one rounded pin (some older dryer plugs had a three bladed configuration (two hots and a ground) and no rounded pin). The rounded pin is the ground. One flat plug is the neutral and the other two are hot. If you put a volt meter from the ground to neutral, you should read 0 volts.
From the neutral to L1, one hot blade you will read 120 volts. From the neutral to the other hot blade , L2, you will read 120 volts.
From the hot L2 to the hot L1 you will read 240 volts.

Check this site...RV Electric

So if you have a 4 prong dryer plug that reads 240 volts on L1 to L2 and 120 volts fro Le to N and L2 to n, you can get a 50 to 30 amp "dog bone" adapter at the Rv place and plug your 30 amp RV in.

To confirm this, check the voltage on the 30 amp end of the adapter. You should have from either the neutral or ground to the hot, 120 volts and 0 volts from neutral to ground.

Ken

Ramblin · 05-11-2012, 08:17 PM

Regardless of how you wire it, it will not be protected by the breaker. It's not gonna be safe, even if you can make it work. One overloaded leg will probably not be able to trip the double pole breaker. There is no safe way to do this. You are risking catching the house on fire by overloading the wire to the outlet. Don't do it.

TXiceman · 05-11-2012, 08:29 PM

Ramblin, the Rv is protected by the breakers in it's service panel. The cord to the breaker is a 30 amp cord and the breaker at the dryer is 50 amps, so that is not protected. You have the exact same situation at any RV park that you use a 50 to 30 amp adapter.

To be safe, you can build or have an electrician make a subpanel off the 50 amp dryer plug with a 30 amp breaker in it for the RV and set an RV 30 amp plug. It is not that hard to do or too expensive.

ken

Ramblin · 05-12-2012, 06:07 AM

Quote:

Originally Posted by TXiceman

Ramblin, the Rv is protected by the breakers in it's service panel. The cord to the breaker is a 30 amp cord and the breaker at the dryer is 50 amps, so that is not protected. You have the exact same situation at any RV park that you use a 50 to 30 amp adapter.

To be safe, you can build or have an electrician make a subpanel off the 50 amp dryer plug with a 30 amp breaker in it for the RV and set an RV 30 amp plug. It is not that hard to do or too expensive.

ken

He's talking about wiring an adapter, not a subpanel. Besides, the dryer outlet lacks a neutral that would be required for the subpanel, no?

monkey · 05-12-2012, 08:35 AM

Alot of great info here... Thanks everybody !! I was using a 12ga extension cord to run the ac from a 110 outlet on the house,,, the cord didn't get hot,, (we did the same last year just fine) , but this year the plugs were getting hot... I checked the voltage inside, 122v + - , but with the ac running, it would drop to 105-107v, even after I shut off everything else I could think of... Not good. The amps go up, and so does the heat. Right ? So I'll start by getting a proper camper 30A extension cord, and read everything here again to see what my options are as far as plugging in to the house.
Not running the ac is not an option, as I and 2 Danes live in it while "we" are visiting DW's Mom in AZ.... Thanks again !! Monkey