Friday, February 3, 2023


Expensive mistake when installing 30-amp RV outlet at home


RV Electricity
with Mike Sokol

Dear Mike,
Thank you for bringing the miswiring issue to light. I have been a licensed journeyman electrician for over ten years, but when a customer asked me to install an outside 30-amp outlet for his RV in the driveway, I accidentally wired it up for 240 volts, NOT 120 volts. That was a costly mistake on my part since it destroyed a lot of the RV appliances and electrical system. Yes, I paid for the RV repairs, but I hated to write that check. More folks need to understand that RV electricity does not follow the norm for house wiring. —Adam

Dear Adam,
I get emails like this every week from an electrician or homeowner who’s made this same costly miswiring mistake. An RV 30-amp plug is NOT wired for 240-volts like the home dryer plug it resembles. The first time I saw one of these TT-30 plugs on an RV I also assumed it was 240 volts, until I looked at the plug closely and saw it was listed for 125 volts. That was the hint I needed to avoid making an expensive mistake as well.

Below is what a 30-amp/120-volt RV outlet looks like compared to a 30-amp/240-volt dryer outlet. See why electricians can be easily confused.


And this is how a 30-amp RV outlet is supposed to be wired.


If you’re going to have a 30-amp RV outlet wired up for your RV when it’s parked at home, be sure to show this to your electrician before he makes a costly mistake. Plus, it’s really a good idea for you to measure every new or unknown RV outlet for correct voltage BEFORE you plug in your expensive RV. And that’s also a great reason to install something like a Progressive Industries EMS on your RV. It’s cheap insurance since it won’t let a 240-volt wiring mistake reach your RV electrical system.

Let’s play safe out there…

rv-safety-764Mike Sokol is an electrical and professional sound expert with 40 years in the industry. Visit for more electrical safety tips. His excellent book RV Electrical Safety is available at



If you value what you learn from, would you please consider becoming a voluntary subscriber by pledging your support? Every contribution, no matter how modest, helps us serve you better. Thank youLearn more here.

Facebook Groups you might like
RVing with Dogs
RV Tech Tips
RV Advice
Towing Behind a Motorhome
RVing Over 70
. . . and the official Facebook page

Winterizing your RV this season? Amazon has a wide choice of RV antifreeze.


0 0 votes
Article Rating
Subscribe to comments
Notify of

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Inline Feedbacks
View all comments
5 months ago

I wanted to comment on FB but comments are closed. To wire it up for 240, you have 4 wires, but the 30a socket has only 3. That means the ignorant electrician put the two hots on the blades, but what did he do with the neutral? Just forget about it?

1 year ago

I have a 150-amp incoming service breaker box on the outside of the house. Can I install a 30-amp plug and breaker for an RV off of this box?

RV Staff
1 year ago
Reply to  Cory

Thanks for the great question, Cory! Look for Mike’s answer in this Saturday’s (Feb. 27) RV Travel Newsletter. Take care. 🙂 —Diane at

6 years ago

Most stupid set-up ever seen and to make matters worst, Canada’s dryer plug is different

Mike Sokol
6 years ago

I’ve had a few emails about how to hook up a 50 amp service, so I’ll answer that in next week’s Q&A.

Tommy Molnar
6 years ago

Thanks for the diagram. I just printed it out and will put it in our trailer.

Subscribe to our newsletter

Every Saturday and Sunday morning. Serving RVers for more than 20 years.