50 amp.... Why so big?

**BobLandry** · 04-19-2021, 05:56 AM

Another misconception is that 50A of power is being forced into your trailer. It is not. It simply means that 50A of power is available. You are still limited by the size of the main breaker in your trailer. So, you are not in danger of burning up anything just by being plugged into a correctly wired power source.

**xrated** · 04-19-2021, 06:09 AM

Originally Posted by BobLandry

Another misconception is that 50A of power is being forced into your trailer. It is not. It simply means that 50A of power is available. You are still limited by the size of the main breaker in your trailer. So, you are not in danger of burning up anything just by being plugged into a correctly wired power source.

I know we've been over this a few times....but just for clarification here on the above bold and underlines text.....50 amps of current PER LEG is available, and that is if you are using a 50 amp service cord and NO adapters down to something different.

**BobLandry** · 04-19-2021, 07:39 AM

I think it could be assumed that my post was relevant to having two legs since that is what 50A service is comprised of.
It also applies to someone using a dogbone to run a 30A trailer into a 50A pedestal. There is stiil 50A available as determined by the breaker on the pedestal, but is limited by the 30A main breaker at the trailer.

**xrated** · 04-19-2021, 11:34 AM

Originally Posted by BobLandry

I think it could be assumed that my post was relevant to having two legs since that is what 50A service is comprised of.
It also applies to someone using a dogbone to run a 30A trailer into a 50A pedestal. There is stiil 50A available as determined by the breaker on the pedestal, but is limited by the 30A main breaker at the trailer.

Bob....I totally understand, and my reply wasn't necessarily directed to you. There are so many people though that truly do not know much about the electrical systems in the RVs, especially the nuances of the 50A RV configuration....so I just wanted to state exactly what is there....and maybe derail any other possible confusion.

**Overtaxed** · 04-26-2021, 07:25 PM

One of my funnier pre-purchase discussions was talking about the right kind of outlet/power to put in for my RV at home. I got dozens of responses (not here), "Make sure you don't put 220 service in!!". I'm staring at the 14-50R thinking "This is a two phase plug, how on earth do I wire it for 120?!".

The answer, of course, as stated by others is simple, RV's use a "220 outlet" (in electrical terms), but they use it as 2 independent 120V circuits. But if you go out to my RV and go hot 1 to hot 2, you will, as expected, get 220V on the volt meter. It IS a 220 outlet, just being used in a different way.

Also, interestingly, you COULD wire the RV plug to not provide 220. If you take hot 1 and put it on a single pole breaker and then hot 2 and put it on another breaker on the same phase on the meter box, you'd have two hots at 110 and NO 220. Do NOT do this; just wire up a standard 220 outlet with 4 wires, hot 1, hot 2, neutral, ground, and it'll work fine. 6GA for the hot/hot/neutral and 8 or 10G for the ground. And if you're having an electrican do it, don't tell him you want a 110V 50A plug. He'll look at you like you have 2 heads. Hand him an 14-50R and ask him to "wire it correctly" and everything will work great. Hot to hot will read 220V, hot to anything else will read 110V.

If you poke around in your transfer switch you'll see 220V there too, it's just that inside the RV, there aren't any "double pole" breakers, so the 220V only exists at the panel, not any of the circuits inside the RV. Think of a house panel without any double pole breakers, it's the same thing. Even though every plug would be 110V, you'd still have 220 inside the box, you're just not using it.

**Jerryr** · 04-26-2021, 07:50 PM

Originally Posted by Overtaxed

One of my funnier pre-purchase discussions was talking about the right kind of outlet/power to put in for my RV at home. I got dozens of responses (not here), "Make sure you don't put 220 service in!!". I'm staring at the 14-50R thinking "This is a two phase plug, how on earth do I wire it for 120?!".

The answer, of course, as stated by others is simple, RV's use a "220 outlet" (in electrical terms), but they use it as 2 independent 120V circuits. But if you go out to my RV and go hot 1 to hot 2, you will, as expected, get 220V on the volt meter. It IS a 220 outlet, just being used in a different way.

Also, interestingly, you COULD wire the RV plug to not provide 220. If you take hot 1 and put it on a single pole breaker and then hot 2 and put it on another breaker on the same phase on the meter box, you'd have two hots at 110 and NO 220. Do NOT do this; just wire up a standard 220 outlet with 4 wires, hot 1, hot 2, neutral, ground, and it'll work fine. 6GA for the hot/hot/neutral and 8 or 10G for the ground. And if you're having an electrican do it, don't tell him you want a 110V 50A plug. He'll look at you like you have 2 heads. Hand him an 14-50R and ask him to "wire it correctly" and everything will work great. Hot to hot will read 220V, hot to anything else will read 110V.

If you poke around in your transfer switch you'll see 220V there too, it's just that inside the RV, there aren't any "double pole" breakers, so the 220V only exists at the panel, not any of the circuits inside the RV. Think of a house panel without any double pole breakers, it's the same thing. Even though every plug would be 110V, you'd still have 220 inside the box, you're just not using it.

Actually you can use 8AWG THHN or THWN stranded wire in conduit for 50 amp. If using NM-B or UF-B Romex® you will need 6/3 w/ground.

**xrated** · 04-26-2021, 08:02 PM

Originally Posted by Overtaxed

One of my funnier pre-purchase discussions was talking about the right kind of outlet/power to put in for my RV at home. I got dozens of responses (not here), "Make sure you don't put 220 service in!!". I'm staring at the 14-50R thinking "This is a two phase plug, how on earth do I wire it for 120?!".

The answer, of course, as stated by others is simple, RV's use a "220 outlet" (in electrical terms), but they use it as 2 independent 120V circuits. But if you go out to my RV and go hot 1 to hot 2, you will, as expected, get 220V on the volt meter. It IS a 220 outlet, just being used in a different way.

Also, interestingly, you COULD wire the RV plug to not provide 220. If you take hot 1 and put it on a single pole breaker and then hot 2 and put it on another breaker on the same phase on the meter box, you'd have two hots at 110 and NO 220. Do NOT do this; just wire up a standard 220 outlet with 4 wires, hot 1, hot 2, neutral, ground, and it'll work fine. 6GA for the hot/hot/neutral and 8 or 10G for the ground. And if you're having an electrican do it, don't tell him you want a 110V 50A plug. He'll look at you like you have 2 heads. Hand him an 14-50R and ask him to "wire it correctly" and everything will work great. Hot to hot will read 220V, hot to anything else will read 110V.

If you poke around in your transfer switch you'll see 220V there too, it's just that inside the RV, there aren't any "double pole" breakers, so the 220V only exists at the panel, not any of the circuits inside the RV. Think of a house panel without any double pole breakers, it's the same thing. Even though every plug would be 110V, you'd still have 220 inside the box, you're just not using it.

While in theory, that would be possible, the reality is that eventually there would be smoke, then fire, then poof! I do realize that you said DO NOT do this, and that is great advice. Two individual 50 amp circuits being fed from the same leg would allow you to have a total of 100 amps. The problem is that the neutral wire, is still only 6 ga and if you loaded up both of those circuits, the neutral would definitely overheat, then start smoking, then the fire, then the Poof. Plus the fact that it would likely be against the NEC.

**Overtaxed** · 04-26-2021, 08:03 PM

Originally Posted by Jerryr

Actually you can use 8AWG THHN or THWN stranded wire in conduit for 50 amp. If using NM-B or UF-B Romex® you will need 6/3 w/ground.

Yup, I actually used THWN and the price of 8 and 6 was so close, I just went to 6. Figured I'm only doing it once, might as well deal with wrestling 6GA, not like 8 is that much better. I always upsize my fixed runs in conduit, figure it's less voltage drop, less heat in the wire, and could be upgraded in the future if need be (like swapping the 50A plug for a small subpanel, hot/hot/ground/N there, so I could put in a subpanel if I wanted one.

This is the actual wire I used, it's 194 rated so good to 75A. More than enough power for the RV running everything at one time. Also good if I need to drag my welder out there to put something back together.

**Overtaxed** · 04-26-2021, 08:07 PM

Originally Posted by xrated

While in theory, that would be possible, the reality is that eventually there would be smoke, then fire, then poof! I do realize that you said DO NOT do this, and that is great advice. Two individual 50 amp circuits being fed from the same leg would allow you to have a total of 100 amps. The problem is that the neutral wire, is still only 6 ga and if you loaded up both of those circuits, the neutral would definitely overheat, then start smoking, then the fire, then the Poof.

Yup. You'd need to upsize the N to 2 or 3 ga to support this insane way to wire. And nobody should EVER do it, there's no reason for it, you're RV wants a standard 220 outlet w/a neutral line. But when everyone told me "Don't wire it for 220, you'll burn down the RV" I started to think about how on earth you could possibly wire a 14-50R to be a 110 outlet (only) and that's all I came up with.

Maybe there's another way to do it that I'm didn't figure you, but let me save everyone the trouble, you want a standard wiring L14-50 outlet. Any electrician will know how to wire it correctly, there's absolutely NOTHING special about this service what so ever.

**Jerryr** · 04-26-2021, 08:15 PM

Originally Posted by Overtaxed

Yup, I actually used THWN and the price of 8 and 6 was so close, I just went to 6. Figured I'm only doing it once, might as well deal with wrestling 6GA, not like 8 is that much better. I always upsize my fixed runs in conduit, figure it's less voltage drop, less heat in the wire, and could be upgraded in the future if need be (like swapping the 50A plug for a small subpanel, hot/hot/ground/N there, so I could put in a subpanel if I wanted one.

This is the actual wire I used, it's 194 rated so good to 75A. More than enough power for the RV running everything at one time. Also good if I need to drag my welder out there to put something back together.

8 is way easier to wrestle in small spaces. Especially in a 4” box.

Yep, I have 6 THWN out to my 60 amp barn sub panel.

It feeds pumps, lights and a 14-50R with 40 AMP breaker for my electric car charger. I occasionally plug my RV into it.