Note: Please do not try this at home unless you have a good idea what you are doing! Connecting 240 volts to your RV would probably result in “very bad things” ! Always check that a new adapter actually is 120 volts with a voltmeter, and that it is wired correctly with ground.
From time to time we stop off at a friends or relatives house and there is a convenient dryer outlet nearby, which of course we have no way to use.
Now, a standard dryer is 240 volts, and our RV is 120 volts, but that it is not a problem because the dryer outlet achieves 240 volts by using (2) voltage feeds combined, each 120 volts.
So we just need to use half of the dryer outlet.
The picture above shows a few ways to do it. The bottom picture is the most straightforward way – its a simple adapter that has a 4 wire 240 volt dryer plug on one side and a 30 amps 12 volt RV outlet on the other. Just plug in your RV!
In case you have an older 3 wire dryer outlet, the picture on the top left is an 3 wire dryer adapter. The extra green wire you plug into the ground connection of any nearby outlet.
So with these two adapters (Amazon links all below) you can plug your 120 volt RV into any dryer outlet and enjoy the full 30 amps.
But I also have a brother who has a dryer outlet a distance from his driveway. So I made the adapter cable on the right. Its a standard 4 wire dryer cord that I connected to a heavy duty 20 amp outlet for a standard 120 volt AC plug. This will be used with his extra heavy duty 50 foot 120 volt extension cord to deliver up to 20 amps to the RV in case some extra distance is needed. It also can use the 4 wire to 3 wire dryer adapter if necessary.
It was fairly easy to make this adapter cable, since the 10 gauge wire just (barely) fits. It took a little patience to get the over-sized wires all in the holes to tighten but came out perfect. This is a safe adapter but you are on the honor system not to draw more than the 20 amps the 120 volt outlet is rated for! (The extra red wire is not used and I cut it off)
So now with this kit I can mooch off of friends as long as I want, at least until somebody wants to start the dryer.
Here are the parts I used:
(Links are paid)
Dryer outlet to 30 amp RV adapter ————– AC Adapter Cord NEMA Dryer 14-30P to TT-30R RV 30A 125V
3 wire to 4 wire dryer adapter ——————— 3 Prong to 4 Prong Dryer Plug Adapter with Green Ground
And, to make your own dryer outlet to 120 volt plug, you will both: