RV wiring / trailer question

[Rockcrawlindude]

HD ram fam

I purchased an enclosed trailer for transporting and storing my rock crawler. I got it optioned with 120v RV plug which controls the lighting and outlets. All I want are power outlets and lights. Not gonna be running any 240v stuff

I figured it was set up to be plug and play at an Rv site but I would like to have power to it when it is parked at home to keep the toy on a battery maintainer and to have operational lighting. My thought was to buy an adapter but none of the adapters are for this plug.

So I opened it up.

To me, it seems like they used the wrong whip and plug. It looks like a 240v situation utilizing only one of the hots. It looks like a common 50 amp RV plug. Is this correct for 120v?

This is a picture of the electrical panel inside the trailer. (The red wire is capped off and tucked behind) I don’t know why they used a double pole breaker maybe so it can be converted to 240v easily

 

[Rockcrawlindude]

Is it safe to use a 50amp > 30amp adapter and then use a 30amp > 15amp adapter to plug it in at home with a 100ft 10ga ext cord?

No ac units or anything just lights, well under 15 amps

 

[Jacob]

You can probably get a 50amp rv to 115v household adapter. Skip the 30amp rv adapter. I think it would be ok with extension cord. As far as I know, all rv stuff is 115 not 240.

 

[Jacob]

 

[Grateful Dad]

Use the adapter above and you’ll be good to go.

I run my 5ver at home off an adapter to a regular outlet, can run 1a/c without popping it though the breaker for that circuit is a 20 amp, not the standard 15.

I never had a camper with 50 amp service until this 5ver, they are wired up for 100 amps, split on 2 50 amp runs so to speak. Typical 50 amp is needed if you have 2 a/c units, each unit on a separate run.

 

[Rockcrawlindude]

View attachment 41239

Dang I totally overlooked this one. I’m going back on Amazon right now thanks

 

[Rockcrawlindude]

You can probably get a 50amp rv to 115v household adapter. Skip the 30amp rv adapter. I think it would be ok with extension cord. As far as I know, all rv stuff is 115 not 240.

Thanks for the info. So, it’s normal for the Red wire to be capped off in the RV breaker panel?

 

[Jacob]

I don't think so. I'm not an electrical genius. I installed a surge protector on my camper. Here's a before photo I took.

 

[I Love Grits]

Thanks for the info. So, it’s normal for the Red wire to be capped off in the RV breaker panel?

You’re running everything off 120V aka one leg (black wire). The jumper between the buses allows you to use the top double breaker as a disconnect and add breakers without having to “skip slots” to grab power off the bus.

If you were running 240V, the red wire would be hooked to one bus and the black the other. Each wire supplies 120 so a breaker that connects to both would have 240 to it.

So yes, if the intention is to only have 120V in the trailer, the red wire is not needed - hence why it’s capped. It comes with the extension cord so that’s why it’s there.

 

[Rockcrawlindude]

@I Love Grits Thanks for the clarification. I’ve never seen a breaker panel wired like that.

@Jacob that looks like 240v with that black and red going to that double pole feeding the panel.

 

[Poolmonkey]

I would just wire a standard 120 cord in place of that whip..every RV spot I have used has provision to plug in a standard cord…if you are certain to never want 240

 

[MikeXM]

Your panel is wired as a single 120V circuit and your loads are on a single 15Amp circuit. All is good.

The 50A breaker is used only as the power input of the panel, before distribution. The second 50A breaker could be used to feed a 120V 50A load. But as of now, since only a single 15A breaker is in use, you can connect your power plug to a 250V 50A, 120V 30A or a 120V 15/20A power outlet with proper adapters without any worries.

If you would use the 2nd 15A breaker, like to install a power outlet in your trailer, you should then plug only to a 250V 50A or 120V 30A circuit to be sure there is enough power to supply both 15A breaker loads.

 

[Brutal_HO]

Thanks for the info. So, it’s normal for the Red wire to be capped off in the RV breaker panel?

No, it should be in the other side of that double 50A breaker BUT YOU NEED TO REMOVE THE SHORT BLACK JUMPER. One leg supplies power to the left side breakers, the other to the right side breakers (currently empty.)

Taping off a LIVE WIRE like that (when plugged in) and shoving it in there like that is just dumb.

You’re running everything off 120V aka one leg (black wire). The jumper between the buses allows you to use the top double breaker as a disconnect and add breakers without having to “skip slots” to grab power off the bus.

If you were running 240V, the red wire would be hooked to one bus and the black the other. Each wire supplies 120 so a breaker that connects to both would have 240 to it.

So yes, if the intention is to only have 120V in the trailer, the red wire is not needed - hence why it’s capped. It comes with the extension cord so that’s why it’s there.

I would just wire a standard 120 cord in place of that whip..every RV spot I have used has provision to plug in a standard cord…if you are certain to never want 240

30A and 50A RV plugs are NEVER "240V."

They are 120V on two legs (L1, L2).

A typical RV has a split panel. AC/DC Converter, Main/Single AC, receptacles, WH, on the L1 and the 2nd AC, GFCI, Fridge, Fireplace, etc. and sometimes optional appliances (outdoor fridge, etc.) on the L2 leg. They're all subject to differences but since WFCO supplies most of the panels, surprisingly similar.

The dogbone adapters will connect a single 120V line to both L1 and L2 (L1/L2 bonded) so everything still works, though you will pop smoke if you exceed the rating of the pedestal (feeder circuit.)

Here's what my RV panel looks like.

Below that several reference wiring images.

 

[Nick]

Go by what Brutal is telling you .

 

[I Love Grits]

@Brutal_HO

Running the red wire to the other terminal of the 50A double breaker will still supply the other bus with power, just like the jumper is doing. I guess I’m missing what harm is there in having both busses energized?

What single phase system gets 240V if not from two 120V legs? The “Never 240V” comment confuses me. The plug schematics you posted show 240V between the two legs…

I’d be more worried about having wires exiting the knockout in the back of the box without a bushing or similar than having the red leg capped off inside a locked enclosure but to each their own.

@Rockcrawlerdude for what you’re wanting to do, I’d run the setup and not think twice. If you wanted to clean things up a bit, you could connect the red wire to the other terminal of the breaker acting as the main disconnect and get rid of the black jumper. Both busses would be available for breakers just like they are now. In addition, this means you could install a double pole breaker in the future and have 240V available if you ever had a tool that needed it.

 

[H3LZSN1P3R]

Yea its feeding 120 to both sides of the panel and 240V only comes from putting a breaker on both legs, you are wired normally with a traditional 50A plug.

 

[MikeXM]

@Brutal_HO

Running the red wire to the other terminal of the 50A double breaker will still supply the other bus with power, just like the jumper is doing. I guess I’m missing what harm is there in having both busses energized?

What single phase system gets 240V if not from two 120V legs? The “Never 240V” comment confuses me. The plug schematics you posted show 240V between the two legs…

I’d be more worried about having wires exiting the knockout in the back of the box without a bushing or similar than having the red leg capped off inside a locked enclosure but to each their own.

@Rockcrawlerdude for what you’re wanting to do, I’d run the setup and not think twice. If you wanted to clean things up a bit, you could connect the red wire to the other terminal of the breaker acting as the main disconnect and get rid of the black jumper. Both busses would be available for breakers just like they are now. In addition, this means you could install a double pole breaker in the future and have 240V available if you ever had a tool that needed it.

That is all good. I think if you use the second red wire, you might not get energized on that leg if you connect to a 120V 30A/20/15A outlet. It really depends on the adapter cable used. If you don't connect the red wire, you are basically bullet proof for any outlet if you only need 120V like said.

I don't like the way the red cable is terminated though. Make sure it was not stripped at the end then taped over! That would be very stupid. It must be cut flush and taped over at a minimum. Or use a Marrette of proper size to terminate correctly. EDIT: after a second look at pictures, it might already been terminated by a Marrette and taped over?

30A and 50A RV plugs are NEVER "240V."

Wrong. Or at least saying that is confusing for most people. When you are talking about 240V with average Joe, that is exactly what we are talking about. 2x 120V legs.

The 4 prong 50A RV outlet outlet are definitively 240V, with middle neutral. They are the same outlet as for your kitchen over.

The 30A RV outlet are different beast being only 120V, a 3 prong outlet.

 

[MikeXM]

@Brutal_HO

What single phase system gets 240V if not from two 120V legs? The “Never 240V” comment confuses me. The plug schematics you posted show 240V between the two legs…

He is not technically wrong. But when talking about 240V in North America it is what we are talking about. It's not a 240V single phase. All your 240V house devices are getting 240V from two opposite 120V legs.

If you are in Europe then you get a single phase 240V (a true 240V lol).

 

[I Love Grits]

I think if you use the second red wire, you might not get energized on that leg if you connect to a 120V 30A/20/15A outlet. It really depends on the adapter cable used.

Good point. Leaving it as is would certainly be the best option to avoid a potential adapter issue.

 

[Brutal_HO]

That is all good. I think if you use the second red wire, you might not get energized on that leg if you connect to a 120V 30A/20/15A outlet. It really depends on the adapter cable used. If you don't connect the red wire, you are basically bullet proof for any outlet if you only need 120V like said.

I don't like the way the red cable is terminated though. Make sure it was not stripped at the end then taped over! That would be very stupid. It must be cut flush and taped over at a minimum. Or use a Marrette of proper size to terminate correctly. EDIT: after a second look at pictures, it might already been terminated by a Marrette and taped over?


Wrong. Or at least saying that is confusing for most people. When you are talking about 240V with average Joe, that is exactly what we are talking about. 2x 120V legs.

The 4 prong 50A RV outlet outlet are definitively 240V, with middle neutral. They are the same outlet as for your kitchen over.

The 30A RV outlet are different beast being only 120V, a 3 prong outlet.

It's semantics. The RV is 120V. Saying it's 240V is also confusing for new RV owners.

In my case, I also work on a lot of 208V single phase equipment, so for me it's best to think in those terms. I think we're all in agreement how it works, perhaps just not how to describe it.

RE: adapters. Unless you built it yourself and didn't connect them, all commercially available 50A dogbone adapters connect L1 and L2 together so the red wire is going to be energized. In my mind, it's just plain dumb that it wasn't connected to the breaker seeing that it's a 2-pole breaker. Perhaps it's marginal, but it would be safer connected to the breaker.