30 amp to 50 amp conversion

[FLMedic]

I just realized today that my single 13,500 BTU AC is not quite adequate for the Florida heat. I have a 1995 31' Land Yacht LE. I am considering adding an additional roof AC in the bedroom or at least upgrading to a 15,000 BTU AC. But I really don`t think a single unit is going to cut it. I realize I will have to upgrade to 50 AMP. Has anyone done this? And is the Land Yacht LE prewired for an additional AC? Any info would be greatly appreciated.

[richinny]

you'll find some information here:
http://www.airforums.com/forums/f427...ml#post1140320

[FLMedic]

Well, I have yet to find a service center who will attempt the conversion. Or maybe they just don't know how. I've tried Camping Wxxxd and a couple others here in Jacksonville. No luck yet. I hope someone can help steer me in the right direction.

[xrvr]

Try jd sanders airstream in alachua, near Gainesville. Call and ask for mark, he will tell you if they can do it or not. Jim

[DaveFL]

Is the land yacht le a MH or trailer?

[Mike Leary]

Originally Posted by DaveFL

Is the land yacht le a MH or trailer?

Matters not, AS was was not thinking that parks would go 50 amp and, therefore, be able to run both roof airs. We have the same problem, dual roof, 30 amps, without tearing out the whole rear inside, it's impossible to get to all the connections to run the rear air and still be able to run both roofs from the gen set.

[xrvr]

Seems there was a thread years ago on how both acs could operate at once. Jim

[xrvr]

Search running two air conditioners at once, jim

[TG Twinkie]

Are both A/C's fed from the same circuit breaker? If they have separate breakers that means they are wired separately.
If one were to wire the panel for 220/240 volts, one hot leg could provide power to A/C #1, the other hot leg could provide power to A/C #2.
Most panels I've seen in RV's have a "split buss" system. this is the reason there is a jumper between the 2 big lugs in the panel on the hot side.
If you remove the jumper and wire the shore power cord for 220 volts then connect each of the two hot legs to their respective hot lugs (L1 and L2) and the neutral and the ground to their respective terminating points. All devices would still be powered by 110volts.
It would however require a panel with enough capacity to install a two pole main breaker instead of a single as we are use to seeing.
If the panel had the capacity (space) to install all of the breakers in that exist today one the L1 buss except for the second A/C. All systems would function as they do today.
The second A/C would run off of the L2 buss.
This would require a 4 wire shore power cord L1,L2, Neutral and ground.
With an adaptor wired correctly for a 30 amp 110 on one end and a 4 wire receptacle on the other, you could plug in to the standard 30 amp receptacle where there are no 50 amp/220 receptacles available. All systems would work normally except the second A/C would not have power.
This setup assumes that the 50 amp service at campgrounds is a 220 volt 4 wire system.
If not, then I've typed this for nothing. LOL

[JimGolden]

Have you painted your roof white?

I have a 34 footer and a Carrier 15,000BTU a/c and it keeps it nice and cool inside. BUT, before I even upgraded to the new Carrier, I painted the roof white on my coach and, no exaggeration, it dropped the temps 10 degrees!

You need to use the right process for aluminum if you want to do it. I got a metal etcher from Aircraft Spruce and Specialty. You must etch the aluminum first (it's simple, just mask off the big area you want to paint white, then wipe this etching stuff on with a roller....wait so long like a half hour or so, then you rinse it all off with a hose), then you must use a special primer that is made for etched aluminum. I got mine from a buddy who works for US Air and they paint their airplanes with it. But you can also get it from Aircraft Spruce (or Wick's as well). It's typically made of Zinc Chromate or an epoxy substance. But anyway, you first etch it, then you use the correct primer that is made for aluminum. After that, you can use any good paint. I used Rustoleum Gloss White; got a gallon jug at Lowes and put it on with a foam roller. It looks great, and really helps cut the thermal gain.

OK, after you do that, you can still run a 15,000 BTU a/c unit on 30 amp. You just can't run the microwave and a hair dryer at the same time.


As for wiring up a 50 amp, I did get a new 55 amp converter that I plan to install as well. The branch circuitry really doesn't change much; you just have to remove the old converter and replace with the new, and you should have more spaces in it for additional circuit breakers. You'll have to get a new main chord to run from the converter to the 50 amp outlet, but it's not a big deal. Any decent electrician could do this for you.

Best of luck,

[vswingfield]

Originally Posted by JimGolden

...

As for wiring up a 50 amp, I did get a new 55 amp converter that I plan to install as well. The branch circuitry really doesn't change much; you just have to remove the old converter and replace with the new, and you should have more spaces in it for additional circuit breakers. You'll have to get a new main chord to run from the converter to the 50 amp outlet, but it's not a big deal. Any decent electrician could do this for you.

Best of luck,

Changing to a 55 amp converter is completely different than changing the AC service to the entire trailer. The converter's amperage is how many 12 volt DC amps it is capable of putting out to the DC system, including charging the batteries. Changing form 30 amp AC to 50 amp AC is an upgrade to the entire AC supply to the trailer, not the charging power of the converter.

Also, the main AC power cord does not go directly to the converter, but instead, to the main breaker box.

These are completely different systems. The converter merely plugs into one of the outlets wired to one of the breakers.

__________________

Back to the topic of increasing AC capacity to facilitate the addition of a second Air Conditioner. I asked about it in the past, and Andy suggested the addition of a second 30 amp system and cord to power the second unit vs a conversion to a single cord 50 amp system. He said that you could use a 50 to 30 amp adapter to plug one 30 amp cord into the 50 amp outlet and plug the other 30 amp cord into the 30 amp outlet. He claimed that it was easier and less expensive.

I haven't added a second Air Conditioner, but when/if I do, I will consider this option vs converting to a single 50 amp cord.

[DaveFL]

Originally Posted by Mike Leary

Matters not, AS was was not thinking that parks would go 50 amp and, therefore, be able to run both roof airs. We have the same problem, dual roof, 30 amps, without tearing out the whole rear inside, it's impossible to get to all the connections to run the rear air and still be able to run both roofs from the gen set.

Does to anybody giving opinion on system, MH are wired so that the a/c's can be run at the same time from the generator, new wiring can be installed using the exisiting wires. In the genset compartment is a junction box, in it are the two circuits, 30 amp and 20 amp, in the cabinet over the sink is a switch marked Front or Rear A/C when set on front using the genset both work.

[raveson]

I had the same problem on my 345. The difference is there are two air units on the roof and would only both work if gen was on. The gen has two circuts, 30 and 20 amp. I installed from Power Solutions for about $100 a system that allows you to divert the 20 amp circut through an additional cord to the power pole when on shore power, allowing both units to operate. An inexpensive and easy solution. If you have two existing units on the roof, the solution is simple, if an additional unit is added, then more wireing will probably be needed, but hopefully you will not have to go to 50amp service.

[lylesgl]

In addition to the 15K a/c I'm adding a 13.5K to the bedroom area of my 27FB. JC can do the mod by adding a receptical outside the airstream that will power the a/c unit independently. This does away with the need to upgrade to 50amp system.

[DaveFL]

Receptical outside should be a male service connection so that when you plug in at the pole, cord at the trailer would be a female connector and safe to handle when hot.

[JimGolden]

VS,

My initial reaction to your posting was "What??!!" But, I see that I have used the wrong terminology. I stand corrected.

What I have purchased is a Progressive Dynamics Power Control Center. I used the term "converter" in the generic and I see that that is incorrect.

At any rate, take my earlier post and substitute "Power Control Center" for where I said "Converter" and you should be AOK. Yep, the converter is simply that portion of the power control center that "converts" 120v alternating current to 12v direct current. As opposed to an "inverter" (which works the other direction....like you'd find in an ambulance) that inverts 12v dc to 120v ac current.

OK, so all that being said, remember that Watts = power and that amperage times voltage = watts. So, if you are restricted to 120v ac, if you want more power, you need more amps because the voltage doesn't change. Hence the ramp up from 30amp to 50amp. Even though they call it a 50amp, the power control center (not a converter ) says 55amp on it.

Anyway, you will most likely need 50amp service to run two a/c units. But I still say that if you paint your roof white and get a good 15,000 btu unit, you could get by on 30amp. Just can't run the a/c, the microwave, and a hair dryer at the same time.

See you all on the road!

[vswingfield]

Originally Posted by JimGolden

VS,

My initial reaction to your posting was "What??!!" But, I see that I have used the wrong terminology. I stand corrected.

What I have purchased is a Progressive Dynamics Power Control Center. I used the term "converter" in the generic and I see that that is incorrect.

Fair enough. When I first read it, my initial reaction was also "What??!!" Followed by"I don't think that's really what Jim meant."

It's really different in my 83 Excella center bath. The breaker box is in the closet across the hall from the bath and the converter is under the front window over 20 feet away.

Originally Posted by JimGolden

At any rate, take my earlier post and substitute "Power Control Center" for where I said "Converter" and you should be AOK. Yep, the converter is simply that portion of the power control center that "converts" 120v alternating current to 12v direct current. As opposed to an "inverter" (which works the other direction....like you'd find in an ambulance) that inverts 12v dc to 120v ac current.

OK, so all that being said, remember that Watts = power and that amperage times voltage = watts. So, if you are restricted to 120v ac, if you want more power, you need more amps because the voltage doesn't change. Hence the ramp up from 30amp to 50amp. Even though they call it a 50amp, the power control center (not a converter ) says 55amp on it.

Anyway, you will most likely need 50amp service to run two a/c units. But I still say that if you paint your roof white and get a good 15,000 btu unit, you could get by on 30amp. Just can't run the a/c, the microwave, and a hair dryer at the same time.

See you all on the road!

I agree that painting the roof white is worthwhile. I did mine last summer with a couple of coats of Super Therm. The painted area is cool to the touch in full sun on 100°+ days.

I also have a 15,000 Btu Carrier I installed in 2008. I wouldn't call it comfortable on hot days, a second AC would be nice but just not in the cards right now. With shorts and a fan it is OK during the heat of the day. Perfectly fine at night.

I also keep it parked east-west with the bedroom, that doesn't have pano windows, on the west end. That helps too.

[HighFlying]

We have a 34' TT and live in Texas and also found the one 13500 A/C did not cool very well in triple digit weather. I had North Dallas RV in Carrollton, Tx install a second 13500 unit in the bedroom. We took the fantastic fan out and moved it the the bathroom for more airflow, then installed the new a/c in the same hole the fan came out of. We put in a different circuit breaker panel to add another breaker for the second a/c, and installed an electrical inlet just like the new trailers come with, along with a new 50 amp cord. Both a/c's now run at the same time as long as you are plugged into a 50 amp service. If a 30 amp service is all that is available then you can run only one a/c at any given time. The results are nothing short of spectacular, no issues staying cool whatsoever, in fact you will even get cold. I know it's a long way from Florida, but the folks at North Dallas RV are Airstream experts, and did a very good job. They can be reached at 972-242-0404. Hope this helps.

[HighFlying]

Hi just wanted to give an update in our 2nd A/C install. As I mention before we added the second A/C along with upgrading to 50 amp service. Just have to plug in one cord, like the new trailer on the back roadside of trailer and this allows us to run anything in the trailer. We just got back from a week long trip to New Braunfels, Tx where the temperature was running about 95 during the day, and with both A/C's running the front living area stayed 74 degrees with the thermostat set at the same temperature. With the bedroom set about half way down, it would keep the bedroom/bathroom area at 69 degrees. Needless to say we were very comfortable during the day and while sleeping. We could not be happier and would recommend this addition to anyone, who cannot cool their trailers.

[howell57]

Good info on etching top for paint. Understand there is a special paint for the top of coach. The paint has calcium carbonate fillers and surface measures 18 degrees cooler than unpainted surface.