30 Vs 50 Amp

**DalePatterson** · 06-04-2022, 05:07 AM

I know this has been discussed, but I can't find my answer in previous comments. Although I only scrolled back a few pages, but hopefully this is an easy one.

We just purchased a used 2021 260RD. Everything I've read claims this is setup for 50 amps. It only has one AC, but is prepped for a second. I'm not an electrician but I have done plenty of wiring on my own. It's my understanding that 50 amps for an RV has 2 hots, a neutral and a ground. 30 amps has a hot, neutral and a ground. My cable (is huge) and has the 4 plug connector on the male end, a surge protector, but also has 2 different adapters to drop it down to 3 wire. On different forums I see a bunch of people doing that with success, although the electricians who chime in don't like the idea, for good reason.

My question is this: Why is the male plug on my camper only 3 wire? Is the camper equipped to run 50 amps, but only if I add a second AC? And if you do so you also need to swap the main plug on the side of the camper? I felt like I had a pretty good handle on what I'd need until I saw the 3 plug. It seems like the camper was sold with 4 wire cable for 50 amps (which is much bigger and much more expensive) and an adapter to drop one of the hot legs, and only a 3 wire connection to the camper. The main breaker in the camper is also 50 amps. So I'm confused... Thank you in advance

**Second Chance** · 06-04-2022, 05:11 AM

I believe the neutral at the input on the side of the RV is made through metal spring contacts on the perimeter of the cable connector.

Just an add-on... so-called 50 amp service is actually two 50 amp legs for a total of 100 amps capacity. So, it's over 3 times the capacity of 30 amp systems.

Rob

**DalePatterson** · 06-04-2022, 05:26 AM

Ahhh. Thank you. I figured it had to be pretty simple.

**Second Chance** · 06-04-2022, 05:34 AM

Originally Posted by DalePatterson

Ahhh. Thank you. I figured it had to be pretty simple.

@DalePatterson -

I got so caught up in answering your question, I forgot to welcome you to the forum. Welcome! Here are a few tips to help get you started:

1) If you use "Reply With Quote" (to the right of "Reply") as I have here, folks will know to whom you are responding and that person will get a notification.

2) You can also tag folks using the "@" symbol and their user name (as I have done yours) - they'll also get a notification that way.

3) You can create a signature block with your RV and tow vehicle information (see mine below). That way you won't have to repeat that information whenever you post or ask a question - and others won't have to ask. You can create a signature by going to:

Forum Actions (on menu bar) -> Edit Profile -> Edit Signature (under My Settings on the left)

Rob

**BobLandry** · 06-04-2022, 05:49 AM

The metal friction connection is for ground, not neutral. Neutral will always come n on a prong.

**DalePatterson** · 06-04-2022, 05:50 AM

Originally Posted by Second Chance

@DalePatterson -

I got so caught up in answering your question, I forgot to welcome you to the forum. Welcome! Here are a few tips to help get you started:

1) If you use "Reply With Quote" (to the right of "Reply") as I have here, folks will know to whom you are responding and that person will get a notification.

2) You can also tag folks using the "@" symbol and their user name (as I have done yours) - they'll also get a notification that way.

3) You can create a signature block with your RV and tow vehicle information (see mine below). That way you won't have to repeat that information whenever you post or ask a question - and others won't have to ask. You can create a signature by going to:

Forum Actions (on menu bar) -> Edit Profile -> Edit Signature (under My Settings on the left)

Rob

Thank you!

**Second Chance** · 06-04-2022, 06:36 AM

Originally Posted by BobLandry

The metal friction connection is for ground, not neutral. Neutral will always come n on a prong.

Thanks, Bob.

Rob

**Grandesigner** · 06-04-2022, 08:54 AM

Originally Posted by DalePatterson

I know this has been discussed, but I can't find my answer in previous comments. Although I only scrolled back a few pages, but hopefully this is an easy one.

We just purchased a used 2021 260RD. Everything I've read claims this is setup for 50 amps. It only has one AC, but is prepped for a second. I'm not an electrician but I have done plenty of wiring on my own. It's my understanding that 50 amps for an RV has 2 hots, a neutral and a ground. 30 amps has a hot, neutral and a ground. My cable (is huge) and has the 4 plug connector on the male end, a surge protector, but also has 2 different adapters to drop it down to 3 wire. On different forums I see a bunch of people doing that with success, although the electricians who chime in don't like the idea, for good reason.

My question is this: Why is the male plug on my camper only 3 wire? Is the camper equipped to run 50 amps, but only if I add a second AC? And if you do so you also need to swap the main plug on the side of the camper? I felt like I had a pretty good handle on what I'd need until I saw the 3 plug. It seems like the camper was sold with 4 wire cable for 50 amps (which is much bigger and much more expensive) and an adapter to drop one of the hot legs, and only a 3 wire connection to the camper. The main breaker in the camper is also 50 amps. So I'm confused... Thank you in advance

Can you provide a pic of what you are talking about? I am now confused also, lol

**BobLandry** · 06-04-2022, 09:10 AM

This has pretty much been answered. If the trailer has 50A breakers, then it is 50A service. He is only seeing three prongs because without looking at the outside of the connector(s) where the metal ground contact pieces are, only three prongs are noticeable.
The three wire adapters, if he chooses to use them, allow him to connect to another voltage source at the pedestal in the event the park/CG does not have 50A available. They have nothing to do with the setup on the trailer.

**fez111** · 06-11-2022, 09:22 PM

Originally Posted by Second Chance

I believe the neutral at the input on the side of the RV is made through metal spring contacts on the perimeter of the cable connector.
Rob

You are absolutely correct. There is a grounding conductor on the periphery of the female plug that connects into the RV socket. We use a double 90 degree dog bone to connect so the cables hang straight down.

Also, you are correct in that two 50 amp circuits = 100 amps total capacity...as long as they are wired correctly to two different phases of the incoming power. If the various loads are distributed as equally as possible between the two busses than the individual amperage should not exceed the 50 amp per phase capacity.

When forced to connect to a 30 amp source the two hot leads are jumpered together inside one of the plugs.

One other thing to mention... In a 50 amp RV circuit each hot lead is sized to carry 50 amps each...but the neutral is the same size. The reason that the neutral conductor can carry the full 100 amps load is because the two 50 amp phases are 120 degrees apart electrically which causes the current for two phases passing together through the neutral together to effectively cancel each other out. Every house wired with 220 volts is wired the same way.