Converting to 50 amp

CA Traveler wrote:

D&J Wade wrote:

happycamper002 wrote:
It's not all that's cracked up to be. As one poster had said "converting to 50 A is more involved". Some RVs that come with generator has an interlock relay that isolate the generator from shore power every time the rv is plugged in to the pedestal. More like a transfer switch on a solar powered system. When you convert to 50A you will have two separate 120v source using both legs and common neutral of the 240 source. The interlock relay that comes on a 30A panel needs 120v. Since you will be using both 240v hot legs- you can't use this hi voltage to energize the relay coil because it's only rated 120v. There is of course a workaround if you know what you're doing--thus going back to " more involved". It's not just yanking your 30A panel and throwing in a 50A and hope that everything will be a piece of cake. It would be a remiss to assume that anyone who can replace a wall switch is capable of this undertaking.
Do yourself a favor and consult a certified electrician, it may save you from any catastrophe. If you are hell bent on diy (to prove your manhood lol) go for it. Just don't tell anyone you read this. Good luck.

50 amp rv service isn't 240v. It's two separate 120v with 50 amp service on each leg. A 50amp box in an rv uses two separate buss bars to maintain 120v on each side of the electric box. It's really two separate boxes in one.

Let's get it right. It is a 120/240V 50A 4 wire circuit. It's also single phase and a good description is split phase.

It's identical to a house hold 50A oven circuit for example. The common neutral carries the amp difference of the 2 hot leads and every RV uses this characteristic even though few have 240A appliances. The typical RV usage is 120V from either 50A hot lead.

It's called a 50A circuit because the 50A refers to the 240V amp capacity.

I didn't refer to the breaker as a 120/240v 3 pole because in all honesty it's misleading in an rv install. You only achieve 240v when using both 120v legs in a single socket. Since the two leads are kept separate from the main breaker to the rv breaker box and in the rv breaker box, it remains just a simple 120v, it never becomes 240v. The main reason for wanting 50amp service over 30amp service is because you get 12,000 watts of power with 50amp compared to 3,600 watts with 30amp service.

One of my sources http://www.myrv.us/electric/

From the 50amp resource page



This 50-amp service has 4 wires with two 120-volt HOT feeds. It is a misconception that this 50-amp RV service is something special. This service is a STANDARD 120/240 50-amp 3 pole with 4 prongs used for numerous applications.

From this common service we can draw 120 or 240 volts. Each leg is 50 amps @ 120 volts. 50-amp X 120-volt = 6000 watts. But since there are 2 HOT 120-volt legs at 6000 + 6000 = 12,000 watts to use in the RV or 50-amp X 240-volt = 12,000 watts when used as a 240-volt service.
Almost ALL 50-amp wired RV's use both sides of the service separately as 120 volt on each leg. Only a few mostly high-end coaches utilize the 240-volt from this same service.

The 50-amp 3-pole 4-wire service is superior to the 30-amp service because of the total amperage available.

30-amp 120-volt service = 3,600 watts
50-amp 120/240-volt service = 12,000 watts

The half round or U is the ground the one directly below it is the WHITE or neutral and the other two black wires are 180 degrees out of phase with each other are the HOT 120-volt. In reality you have TWO 120 volt split service going into your RV.

D&J Wade wrote:

happycamper002 wrote:
It's not all that's cracked up to be. As one poster had said "converting to 50 A is more involved". Some RVs that come with generator has an interlock relay that isolate the generator from shore power every time the rv is plugged in to the pedestal. More like a transfer switch on a solar powered system. When you convert to 50A you will have two separate 120v source using both legs and common neutral of the 240 source. The interlock relay that comes on a 30A panel needs 120v. Since you will be using both 240v hot legs- you can't use this hi voltage to energize the relay coil because it's only rated 120v. There is of course a workaround if you know what you're doing--thus going back to " more involved". It's not just yanking your 30A panel and throwing in a 50A and hope that everything will be a piece of cake. It would be a remiss to assume that anyone who can replace a wall switch is capable of this undertaking.
Do yourself a favor and consult a certified electrician, it may save you from any catastrophe. If you are hell bent on diy (to prove your manhood lol) go for it. Just don't tell anyone you read this. Good luck.

50 amp rv service isn't 240v. It's two separate 120v with 50 amp service on each leg. A 50amp box in an rv uses two separate buss bars to maintain 120v on each side of the electric box. It's really two separate boxes in one.

Let's get it right. It is a 120/240V 50A 4 wire circuit. It's also single phase and a good description is split phase.

It's identical to a house hold 50A oven circuit for example. The common neutral carries the amp difference of the 2 hot leads and every RV uses this characteristic even though few have 240A appliances. The typical RV usage is 120V from either 50A hot lead.

It's called a 50A circuit because the 50A refers to the 240V amp capacity.

happycamper002 wrote:
It's not all that's cracked up to be. As one poster had said "converting to 50 A is more involved". Some RVs that come with generator has an interlock relay that isolate the generator from shore power every time the rv is plugged in to the pedestal. More like a transfer switch on a solar powered system. When you convert to 50A you will have two separate 120v source using both legs and common neutral of the 240 source. The interlock relay that comes on a 30A panel needs 120v. Since you will be using both 240v hot legs- you can't use this hi voltage to energize the relay coil because it's only rated 120v. There is of course a workaround if you know what you're doing--thus going back to " more involved". It's not just yanking your 30A panel and throwing in a 50A and hope that everything will be a piece of cake. It would be a remiss to assume that anyone who can replace a wall switch is capable of this undertaking.
Do yourself a favor and consult a certified electrician, it may save you from any catastrophe. If you are hell bent on diy (to prove your manhood lol) go for it. Just don't tell anyone you read this. Good luck.

50 amp rv service isn't 240v. It's two separate 120v with 50 amp service on each leg. A 50amp box in an rv uses two separate buss bars to maintain 120v on each side of the electric box. It's really two separate boxes in one.

Thanks to everyone for their replies.

The decision has been made NOT to make the conversion.

The OP has a TT, & TT with a transfer switch & ginny are very rare so the simple method CA TRAVELER & I described is very easy to do & most likely what he needs. I balanced the loads in ours which I prefer but is not totally necessary. :)

So far 2 ways have been described. 1) add new 50 amp cord and small breaker panel, make the existing panel a sub and move some of the existing circuits to balance the load. That is what I did, biggest expense is the 50 amp power cord and you may not get full 100 amps since one side may be limited to the 30 amp sub and the other leg limited by how many circuits you can move. 2) just run an independent 20 amp power cord and breaker for the 2nd AC

I converted my trailer to 50 amp. Quite easy. Installed the 50 amp receptacle for the cord on the trailer. Ran the wire, 6 or 8 gauge I think, to a new box that had a 50 amp main breaker. Pulled the feeds from the existing 30 amp that powered the A/C, water heater, microwave and put them in the new 50 amp with appropriate breakers. Ran a 30 amp feed with appropriate breaker to the existing 30 amp box and left the remaining circuits intact. Installed several new 20 amp circuits to power portable electric heaters.

CA Traveler and TVman44 gave the best answer.

You just need a 50 amp panel, cord, wire, and possibly transfer switch.
The hard part is pulling 50amp romex from the inlet to the panel, depends on access and distance.
Rest is just tedious connections in the new panel.

It's not all that's cracked up to be. As one poster had said "converting to 50 A is more involved". Some RVs that come with generator has an interlock relay that isolate the generator from shore power every time the rv is plugged in to the pedestal. More like a transfer switch on a solar powered system. When you convert to 50A you will have two separate 120v source using both legs and common neutral of the 240 source. The interlock relay that comes on a 30A panel needs 120v. Since you will be using both 240v hot legs- you can't use this hi voltage to energize the relay coil because it's only rated 120v. There is of course a workaround if you know what you're doing--thus going back to " more involved". It's not just yanking your 30A panel and throwing in a 50A and hope that everything will be a piece of cake. It would be a remiss to assume that anyone who can replace a wall switch is capable of this undertaking.
Do yourself a favor and consult a certified electrician, it may save you from any catastrophe. If you are hell bent on diy (to prove your manhood lol) go for it. Just don't tell anyone you read this. Good luck.