50 Amp Power Distribution

When connected to 50 amp service, what circuits are fed from each side of the 110 vAC that the 50 amp provides? When connected to 30 amp service, is there a crossover switch that provides 110 vAC to all circuits?

VenningG,

Your 50 to 30 amp adapter does contain a crossover so that all circuits are fed current. But you will be limited to the number of appliances you can use at one time to aprox total current draw of 30 amps.

Jim M

VenningG,

Welcome to the forum!

Jimtoo is spot on as far as a 30 to 50 amp adapter goes - if it's made correctly.

As far as which circuits are on which AC leg, open the cover on your AC breaker panel. As with standard AC panels, past the double-pole main disconnect breakers, every other circuit breaker is on the same AC leg.

As an example, if the double-pole main disconnect breakers occupy, say slots 1-4, then slots 5, 7, 9, 11 etc are on one AC leg, while slots 6, 8, 10, 12 etc are on the other AC leg.

Jim

I bought a triple dog-bone that splits the 50 amp plug into a 30 amp end and a 20 amp end. My guess is that the 30 amp leg goes to the power hungry, high juice grabbers like the a/c and h/w and the 20 amp feeds the other low current stuff. Is that a good guess.

rick_debbie_gallant said:

I bought a triple dog-bone that splits the 50 amp plug into a 30 amp end and a 20 amp end. My guess is that the 30 amp leg goes to the power hungry, high juice grabbers like the a/c and h/w and the 20 amp feeds the other low current stuff. Is that a good guess.

Click to expand...

Rick,

It's an unknown really. But you can test it I suppose. Plug in only one side of that adapter and see what works.

If you have 2 air conditioners, my guess is the breakers are side-by-side in the breaker box, meaning they would be on different AC legs. In this case, one would be carried by one side of this adapter and the other by the other side of the adapter. If that's how those adapters work. No experience with them.

At the end of the day, the adapter does not know how the load is split up in the RV AC panel. If it is evenly distributed, then I suppose the 20 amp leg of your adapter could have a higher load than you'd want. But then, it's really a function of usage.

Let us know how the test comes out

jbeletti said:

If you have 2 air conditioners, my guess is the breakers are side-by-side in the breaker box, meaning they would be on different AC legs. In this case, one would be carried by one side of this adapter and the other by the other side of the adapter.

Click to expand...

And if it is not it would be worth the effort to move the breakers/wires around. At least that way with the 50/30-20 adapter you could use both A/C's, maybe even the hot water heater.

Venning,

I had the same question a few weeks ago, and called upon a couple of electrical engineering buddies. They found what Jim has said is totally correct. The 50 to 30 amp converter plug has the cross over to supply a total of 30 amps at 120 v to the trailer circuit breaker box. The trailer box is set up differently than the standard house wiring. There are 2 main breakers in the center of all the breakers, and the breakers to the left of the mains are fed from the one main just left of center, and likewise for the breakers to the right being fed from the main breaker to the right of center. This breaker box does not allow double breakers to give 240 volts. It acts like 2 separate 120 volt feed circuits when you are plugged into the 4 prong 50 amp pedestal. If you meter the volts at the 2 feed prongs on the pedestal you will read 240 volts, but your trailer converter box is treating them like 2 separate 120 V feeds.

I hope this has helped your understanding, but I know it is confusing because it is not like normal house wiring.

Paul in MN

I hear-tell that the dogbones with the 30 and 20 amp to 50 amp don't work right if the 20 amp side has a ground fault on it. I don't know the particulars about that but if it does not work look at the 20 amp outlet and see if it is GFCI. If so you may be out of luck. There was a discussion about this on the forum sometime back.

The two 30/20/15 amp supplies to the 50 amp RV receptacle (female 50 4 blade) will not work on a gfi circuit supplying either leg.

http://www.tweetys.com/rv50ampcheaterbox.aspx

jmgratz said:

I hear-tell that the dogbones with the 30 and 20 amp to 50 amp don't work right if the 20 amp side has a ground fault on it. I don't know the particulars about that but if it does not work look at the 20 amp outlet and see if it is GFCI. If so you may be out of luck. There was a discussion about this on the forum sometime back.

Click to expand...

You are correct my fine feathered friend . When I stayed at my sister's house a few weeks ago I had to plug into circuts that did not have gfi's on them, if I did try to use gfi the gfi would pop.

In fact in St Ignace a couple of weekends ago I could not reach the boxes with my 50amp so I had to "dogbone" it to two 30 amps with my 30/20=50 dogbone. No problem with the 30. but the 20 had to be dogboned into a 30 so that I could us a 30 from another lot in order to have a 50 (and air).

As I do recall I did get a lot of strange looks because of the way I was set up.

Now for my test tomorrow I will see which one powers the a/c and w/h. I am still guessing that it will be the 30. but we shall see.

Every year we go camping over Labor Day weekend for "Goldstock". This is typical of our "shared services".

There are 9 trailers on this 50 amp circuit, using 100+ feet of 8 gauge supplying this board.