30A vs 50A

The only thing 50 AMP does (vs 30 amp) is let you run BOTH a/c units at the same time. Those that say they run 2 units on 30 amps at the same time, are taking a chance with electrical overload and that can equal a fire. Run both on 20AMP? Hope a fire extinguisher is nearby. IMO a definite recipe for disaster. Again...my opinion.
I have no idea why any coach company would market a unit with 2 a/c units and give 30 amps. IMO (again) that is not only dangerous but stupid. But then, I've seen new units at RV shows with no electrical outlets in the kitchen! How dumb is that?

jsmart wrote:
Just a curious question for all you experts out there, We have a 2002 32V Itasca Sunrise, bought it used, have had it almost 2 years. It has the 30 amp power cord, however, the box the power cord goes into in the lower compartment has a label on it that says "max 50 amp". The electronic control station in the hallway also has indicators for which power source is being used, has light for generator, 20a, 30a and 50a. Is it possible to replace the 30a power cord with a 50a power cord and use 50a power? We have 2 air conditioners and although have never had a problem with power, we do need to watch what we have on at any given time, (i.e., DW can't blow dry her hair while both air conditioners are on). Just a thought.

In 2002 a 50 amp service was an extra cost option. We had it on our 2001 Adventurer. Both the 30 amp and 50 amp versions used the same transfer switch. However the best way to know the differences between the wiring is to look at the Winnebago online wiring diagrams.

http://winnebagoind.com/diagram/Wiring.htm

Not all wiring diagrams are included in this package. If you need more detail you can call the Winnebago customer support number.

http://winnebagoind.com/contact

They will e mail you any information they have.

Over the years there have been many posts here and on IRV2.com about people upgrading from a 30 amp service to a 50 amp service. I didn't pay much attention to the procedures because we already had a 50 amp service.

It always depends on the Size of A/C Unit's how much you can run at the same time.

I've got a 5000 BTU in the back and 13500 BTU in the Front and they do run of an 20A Outlet of my Garage. I can not start the Microwave or a Hairdryer, but everything else is running fine.

An 13500 BTU sucks between 11 and 15 amps,
A 15000 normally less since newer and more efficient. Depending on your unit sure you can run two A/Cs of an 30A Service.

I would like add something else, I am not recommending that anyone do a conversion like I did, all I can say is that it worked for me. jg

Like Jumbojet stated,we had a 94 Winnebago DP that was set up to run the second stage compressor on the basement AC only when the generator was on,it had 30 shore power20 amp .I ripped that out and replaced the 30 amp transfer switch with a 50 amp,replaced the shore power cord with a Marinco 50 amp twist lock,ran both circuits through the new transfer switch ,ran a new circuit to the second stage compressor with a 20 amp breaker like Jumbojet did.Luckily Winnebago had run a # 6 set of wire to the main panel,I was able to change the main to a 50 amp breaker,I have seen the 94 Vectra with factory 50 amp set up,Ours just did not have it.There are several articles online that show how this is done. If you are not technical savvy I would not attempt it as it requires quite a lot of wiring changes.I have seen people with a roof AC put a pig tail on their second unit and just use an extension cord.Good Luck jg

cbr46 wrote:
I thought I said to check the panel box for confirmation
Well, kinda anyway.

And I thought they were 2 legs of a 3P system. Wouldn't that make them 120d out of phase?

Yes, I am out of my element. Those classes were in 1973 . . . . now you have me thinking vectors, delta vs Y, instantaneous currents and a whole lot of other painful memories.

Come to think of it, if they were 120d out of phase then L1 + L2 would be less than 240 . . . . Think I'll go wash the motorhome!

Best,
- bob

Nope, not 3 phase. It's a split single phase with 120 volts either side of neutral. So they are 180* out of phase which means the neutral current really is the difference between the two.
Edit - Ahhh, I see DrewE beat me to it.

cbr46 wrote:
I thought I said to check the panel box for confirmation

cbr46 wrote:
A 50A circuit is actually 2 120V lines so I would guess they are 25A each. If true the breakers on the campground panel box should reflect this.

Well, kinda anyway.

And I thought they were 2 legs of a 3P system. Wouldn't that make them 120d out of phase?

Yes, I am out of my element. Those classes were in 1973 . . . . now you have me thinking vectors, delta vs Y, instantaneous currents and a whole lot of other painful memories.

Come to think of it, if they were 120d out of phase then L1 + L2 would be less than 240 . . . . Think I'll go wash the motorhome!

Best,
- bob

Generally it's a split (single) phase system, so 180° out of phase and 240V between the two lines.

Sometimes range outlets are wired with two phases of a three phase system, particularly in apartment buildings and other structures where a three phase power supply makes more sense than single phase. In that case, the voltage between the phases is indeed less than 240V; it works out to 208V nominal (120/208 three phase supply). Naturally, that means the burners are a little less powerful and the oven heats a little more slowly. The heating elements, of course, don't care that they are running on a lower voltage, and probably last longer.

I doubt very many if any campgrounds would wire the pedestals with two 120V phases of a three phase supply. A more sensible solution (for a three phase service) would be to have separate loops or areas on the three phases, each one wired as a split phase. I suspect some EMS systems in RVs would not like the two hots being 120° out of phase and would shut down the connection, though I don't know that for a fact.

A balanced three phase system has the convenient property that the total power delivered to a restive load is constant, which generally also means that the torque required for the generator is constant and even (and the torque delivered by a three phase motor can be nice and even as well, and it's easier to construct DC power supplies with low ripple, and so forth).

Our RV (Winnebago Chalet Class A, 35') came with a 30 amp system and an EMS that allows us to run 2 ACs simultaneously. The ACs are high efficiency and use approx 15 amps (front) and 10 amps (back). Under this setup we cannot run much else. There is a generator switch that allows us to run the back AC on a separate generator circuit so with the generator running, we have up to 45 amps available (30 for coach and 25 for the back AC circuit). The previous owner ran a separate line to the back circuit so that we can simultaneously plug our RV into 30 amps for most things and 15/20 amps for the back AC. It worked well last week in 100+ degree weather and allowed us to do more than run the ACs.

cbr46 wrote:
I thought I said to check the panel box for confirmation

cbr46 wrote:
A 50A circuit is actually 2 120V lines so I would guess they are 25A each. If true the breakers on the campground panel box should reflect this.

Well, kinda anyway.

And I thought they were 2 legs of a 3P system. Wouldn't that make them 120d out of phase?

Yes, I am out of my element. Those classes were in 1973 . . . . now you have me thinking vectors, delta vs Y, instantaneous currents and a whole lot of other painful memories.

Come to think of it, if they were 120d out of phase then L1 + L2 would be less than 240 . . . . Think I'll go wash the motorhome!

Best,
- bob

Washing the motorhome sounds like a great idea.
3 phase power makes me crazy. Glad I don't deal with it often!

.