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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Highway Yacht on April 24, 2011, 09:11:53 PM

Title: 50 Amp service...Will This Work??
Post by: Highway Yacht on April 24, 2011, 09:11:53 PM
I've got a nice 30 amp RV Electrical Panel Box with a built in 12V converter that I removed from my 98 model Travel Trailer. I also removed a very nice large RV refrigerator with raised Oak Panels, as well as all the other appliances such as the oven, water heater, a/c, etc.. I am planning on using most of these items in my conversion. The only problem I foresee is that I want to wire my bus for 50 Amp service so I can run two roof top a/c's while connected to shorepower. The 30 amp RV power panel I have is only set up for 1 a/c. I had an idea of how I might could still use the 30 amp RV Panel but not sure if it will safely work, so I thought I would ask for opinions and advice. My question is: Can I run the 50 Amp power cord from the shorepower pole into the bus into a 50 amp power panel installed with one 30 amp breaker and one 20 amp breaker. I would run the power from the 30 amp breaker to the 30 amp RV electrical Panel with the built in 12V converter and then throughout the coach just as it was done in the travel trailer. I would then run power from the 20 amp breaker to the 2nd roof top a/c by itself. Does this sound like something that would work?? I've got all the materials to do it this way except for the wire. I would hate to have to go out and purchase all new materials if this would work but I definitely want it to be safe. Any advice or opinions???

Jimmy
Title: Re: 50 Amp service...Will This Work??
Post by: papatony on April 25, 2011, 01:17:34 AM
Jimmy  It would be hard to say without knowing what kind of box you have.  30 amp will run two ac's,but what you need is a delay device so that both ac don't start at the same time. Starting up is when you use the most power,once they get started they don't need a lot. If you know a electrician get their advice even if you have to pay him a couple of hours he can  BE THERE and see exactly what you need . Your going to spend a lot of hours and bucks. Be sure every is up to code if nothing else but Insurance coverage. It could be the best money you spend.
Title: Re: 50 Amp service...Will This Work??
Post by: Sean on April 25, 2011, 01:26:15 AM
Quote from: Highway Yacht on April 24, 2011, 09:11:53 PM
... Can I run the 50 Amp power cord from the shorepower pole into the bus into a 50 amp power panel installed with one 30 amp breaker and one 20 amp breaker. I would run the power from the 30 amp breaker to the 30 amp RV electrical Panel with the built in 12V converter and then throughout the coach just as it was done in the travel trailer. I would then run power from the 20 amp breaker to the 2nd roof top a/c by itself. ...
You'd need to start with a 50-amp, 240/120-volt, four-wire panel and a 50-amp, double-pole main breaker.  Yes, you could run a 30-amp circuit from that panel to your old RV combination converter/panel and use that as a sub-panel.  And, yes, you can also have a 20-amp breaker in this panel to feed a second A/C.  But then why not just put all your breakers in this panel to begin with?  For sure I would put both A/Cs on this panel directly, leaving the 30-amp sub-panel for other loads if you still want to use it.

It's hard to balance the loads across the legs if you have almost everything on a single 30-amp subpanel hung off just one leg.  And having another panel in the coach adds a layer of complexity that is unnecessary.  With two air conditioners, it's a sure bet that your coach is required to have a 50-amp shore service in any case.

-Sean
http://OurOdyssey.BlogSpot.com (http://ourodyssey.blogspot.com)


Title: Re: 50 Amp service...Will This Work??
Post by: TomC on April 25, 2011, 08:10:26 AM
I had no interest in having to balance the loads between the two legs of the 50amp service on either the generator or the shore line.  My bus (along with my truck conversion) is wired straight 120vac.  My generator is also wired straight 120vac.  The only difference in wiring the generator is that you have to run two sets of wires with positive, ground and common, instead of two positives, one common, and one ground for the 120/240v two leg service.

My shore service only uses one leg of the 50amp service-so my shore power is limited to 6,000watts.  Of which I have no problem running all three of my roof airs to initially cool the bus, then when it is cool, I shut one down and have plenty of power left over to run my water heater (one at a time), and all else on board.  I have run two A/C's on 30 amp, but it can trip the power pole circuit breaker. 

I highly recommend straight 120vac-it just makes life a bit simpler.  Good Luck, TomC
Title: Re: 50 Amp service...Will This Work??
Post by: bevans6 on April 25, 2011, 08:21:06 AM
What I have done in the past is about what Robert Glines is advocating in his other thread, which is plug into the 30 amp outlet on the pedestal with my normal cord, and plug into the 20 amp outlet with an additional cord.  While I don't have a multitude of air conditioners, this does let me run two space heaters and run my engine block-heater for those 30 degree nights and morning cold-starts...

Plugging into the 50 amp service and running from one leg is another great way to do, but I rarely stay at places with 50 amp power for some reason.  Maybe I am cheap...   :o

Brian