Skip to main content ↑ ↓
Topic: 30 amp vs 50 amp service (Read 2140 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

30 amp vs 50 amp service

Yahoo Message Number: 1195
I would like to understand 30A vs 50A service. Comments from anyone, especially electricians, are welcomed. I am speaking from the point of view of an Allure owner, not a Prevost (which might really have 240 Volt appliances).

30A RV park service: single 30A breaker, hot, neutral and ground, 120V from hot to neutral.

50A Service: dual 50A breakers, hot1/hot2, neutral and ground, 120V from hot1 to neutral, 120V from hot2 to neutral, and typically (part of my question), 240V between hot1 and hot2. HOWEVER: Since there are no 240V appliances in most (all?) RVs, we don't care if there is 240V between the hots, right? It could be zero volts if fed by two breakers on the same branch. Basically what we have and need is two 120V circuits.

30A to 50A cord adapter: Does it take the 30A hot and apply it both to the 50A hot1 and hot2? If it does, then there is no 240V in the RV and you basically have two 120V circuits in the RV sharing a single 30A RV park circuit. Am I okay so far?

To further understand, is it correct to say that 50A shore power is not 66% more then 30A shore power, but is really 333% more power than a 30A because with 50A we really have TWO 50A 120V circuits vs ONE 30A 120V circuit.

Did I make some bad assumptions?
Herb

CC 2002 Allure

p.s. For electrician, if I were to power the 50A coach service with, lets say, two 20A circuits on the same phase(?), I believe the common neutral would need to be able to carry up to 40A.

Why am I asking? At a work location I have a couple of 20A recepticles available to me which are on different breakers, but the same hot side of the panel (zero volts between the two hots). Can I use the hot wire of each circuit to feed 40A to the coach?

Re: 30 amp vs 50 amp service

Reply #1 –
Yahoo Message Number: 1199
I'm not an electrician..... but I do have some experience.
DON'T put 50A, 240VAC into your coach. It will eat fuses and maybe some equipment. I think you are correct about the two 30A, 120VAC legs. I installed that at my kids house where I spend a bit of time.
In my 4 years of half-timing, I have been satisfied with using only the 30A service that is most available. Even when 50A was available (except in the worst heat) I chose to use the 30A.... the cord was much easier to handle and the roof A/C in my old 1998 Intrigue kept us cool.

Dick May

2002 Intrigue, #11438
Member: CCI, FMCA
Dick May
2002 Intrigue, #11438, towing a
2014 Jeep Gr Cherokee ecoDiesel

Re: 30 amp vs 50 amp service

Reply #2 –
Yahoo Message Number: 1201
I definitely believe you are correct in saying "don't put 240V into coach" -- i.e. two hot leads without neutral.
But WITH a neutral, then it really becomes a 120/240V feed where the coach, I believe, uses the two 120V branches (i.e., each hot to neutral). Without a neutral connected, then the coach as a floating Neutral and all kinds of bad things can happen.

Herb

Re: 30 amp vs 50 amp service

Reply #3 –
Yahoo Message Number: 1206
From your "User's Guide provided by CC you can read the facts. It is written in fairly clear manor.
Section UG3-1. Basically when you are connected to a 50 amp service the way CC has the coach set up you have 2 -120 volt circuits which permit you to operate more equipment at the same time , like 2 air conditioners. It is a 4 wire circuit coming into the coach Two wires hot , neutral, and ground.
As stated by others don't attempt to do 240 volt hookup from home service unless you completely understand the schematic of CC wiring set up.
For those who are taken in by the bootleg 2 plugs in the campground socket deal , be warned that in addition to possibly doing damage to your coach there are some campgrounds which now post signs that you will be liable for damage you may cause to their wiring.
Power boosters are another joke.
Jim WB3DJU

herbstrandberg wrote:
 

Re: 30 amp vs 50 amp service

Reply #4 –
Yahoo Message Number: 1210
Quote from: "
I would like to understand 30A vs 50A service. Comments from

anyone,

Quote
especially electricians, are welcomed.

Hi Herb,

Let me start by stating I am not a licensed electrician. I have wired several locations using 240-volt electrical service for my MH at my residence and at 2 of my brothers' homes. At both of my brothers' places, I made up jumpers to connect my 50 Amp shore line to welder receptacles (they are the same as Range or Dryer receptacles.) You just need to know or determine which slots are hot and which one is neutral. At no time has this caused any problems with the MH or any of the service providers. Please know that nothing in my MH operates on 240 volts. In reality, 240-volt service is nothing more than two 120-volt service lines capable of providing 30 to 50 on each 120 volt wire or conductor. If your MH has 50 AMP service, look at the receptacle where you connect the shore line. It will state 240-volt electrical service at 30 or 50 amps. The major reason to do it is to take advantage of the out of phase 120-volt service to neutral. By doing this, you can use a smaller size wire/conductor to handle the current usage. Further, you now have fuse or breaker protection on both 120-volt circuits. Now you can run both AC units or heat pumps in your MH at the same time because each one is on a separate circuit.

Many campgrounds that I have used only have one phase of 120-volt electrical service at 30 Amps. The adapter cord that connects from the campground outlet to your 50 Amp shore line is wired to place the 120 service on both hot wires of the shore line. If you try to operate dual AC units at the same time, you will probably trip the campground circuit breaker. The current draw (Amps) will probably exceed 30 Amps.

I would not try to use the 2 20 Amp 120 circuits you referenced. The could both be in phase and that could cause the neutral to become overloaded. For what it is worth, I would not try to use them. I think you would be better if you tried to use an existing range receptacle as I have described above.

If you are not comfortable with wiring electrical circuits, please get a qualified person to do the work for you.

Dave G.

2000 CC Allure