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Chaplain Kent · 07-04-2005, 10:13 AM

Now that we are into our first summer with Chummy I keep discovering things that do not make a lot of sense. I have two airconditioners, which alone is odd since we live in Wisconsin. The front AC can quickly turn the coach into an ice box so I have never tried the back AC. On returning from a walk the interior was fairly hot so I went to turn on both AC units. I found that only the front one works on shore power and the gen set. The rear works only with the gen set. Is this common? If not what is wrong? Thirdly, I doubt if this rear AC will ever be used much what would be involved in taking it down?

overlander63 · 07-04-2005, 10:22 AM

Quote:

Originally Posted by Chaplain Kent

Now that we are into our first summer with Chummy I keep discovering things that do not make a lot of sense. I have two airconditioners, which alone is odd since we live in Wisconsin. The front AC can quickly turn the coach into an ice box so I have never tried the back AC. On returning from a walk the interior was fairly hot so I went to turn on both AC units. I found that only the front one works on shore power and the gen set. The rear works only with the gen set. Is this common? If not what is wrong? Thirdly, I doubt if this rear AC will ever be used much what would be involved in taking it down?

Kent, that is how it is supposed to work. Two A/C's will pull about 35 amps if they both try to start at once, which is over what most electrical systems can handle, so the rear is set up for Genset operation only.
If you wanted, you could probably wire the rear air so you could plug it into the genset, or a 30 amp extension cord to plug into a second 30 amp outlet, or plug it back into the genset if you are going boondocking. As far as taking it down, you will wind up with a hole in the roof that would need a vent or patch on it, and IMHO, it would never look right. Besides, you never know when your travels will take you to Florida, or Arizona, or someplace else very hot. Not to mention if the campground has a power failure while you are there, it is very nice to fire up the generator and be in cool comfort until the power is restored.

87MH · 07-04-2005, 10:33 AM

Quote:

Originally Posted by Chaplain Kent

... I found that only the front one works on shore power and the gen set. The rear works only with the gen set. Is this common? .....

There should be (or there probably was) a four to six position switch (look in the overhead compartments in the kitchen area).

The switch allows you to choose ONE of the high amperage appliances while on 30 amp shore power.

Examples of the items on the "switch" would be

Front AC
Rear AC
Ice Maker
Microwave
Compactor
Electric Water Heater
Electric Oven

Chaplain Kent · 07-04-2005, 10:55 AM

Thanks for the information. Yes, we do have a switch that turns the AC on and the microwave off.
I see this rear AC in the same light as 4-wheel drive on my truck. It is something I need to haul around, extra weight and potential expense for limited use. I get through our snowy winters just fine with two wheel drive and imagine I can get along just as well with only one AC. Unless I can make it more useable. Can I install a switch to use the front or the back as I choose on shore power? That way we can cool the back bedroom with the door closed and my grandson napping, while we enjoy the fresh air of camping in the front.
We are leaving now for ten days in a state park with only 20amp service and a "NO Generator" rule. So for the next week and a half it will be no AC.

swebster · 07-04-2005, 11:24 AM

Switching the selector switch to "Rear AC" on shore power should allow you to run the bedroom unit while on shore power.

ALANSD · 07-04-2005, 12:44 PM

we have one ac on our 28, and it is quite sufficient even here in Ga where it gets hot and steamy. However I would not consider removing the 2nd unit, because of decreased resale value and the big headache of sealing up that hole outside and inside. Live with it, turn it on every so soften to keep the seals working right.

Nick Danger · 07-04-2005, 02:06 PM

I have a 1989 370 LE and it has a switch for selecting front/rear AC to work on AC located in a cabinet above the stove. I can fire up both on the generator.

My Airsteam Owners manual states that the rear unit on my rig is the "primary" as it is centrally located, so it should be the one used for initial cooling.

However, after just returning from a trip to Austin, Texas where the heat index daily was >100 each day, I sure would like to figure out a way to get them both running on AC. I didn't know why you couldn't run both on AC until I read Overlander 63's explanation. Seems to make sense to me.

My units now are rated at 14.5 amps at full load. I am going to replace them with new units rated at 10 amps. Does anyone ( Overlander 63) think that since the amperage will be reduced that I may be able to rewire both into working at the same time on 50 amp service?

Any suggestions on this and replacing the units is greatly appreciated. I don't want to go through a week like last week again.

thenewkid64 · 07-04-2005, 03:47 PM

Nick,

The way that your coach is wired internally would need to be modified to allow for both AC's to run on 50 Amp feed at a campground. One way to deal with the issue is to replace the AC's with 15K BTU ones. You likely are running 13.5K or less units.

The new units will work better than the old ones, and the higher BTU can make the difference running on one. That is what I would try first, before rewiring the system to a 50 AMP service.

If you want to rewire the coach to be a 50 amp feed it can be done. Do you have a power reel?

Nick Danger · 07-04-2005, 04:26 PM

Brett.........

I will upgrade the new units to 15's.

If I understand you correctly, are you suggesting two options?

1. Replace the existing units with 15's and realize mnore cooling benefit from one unit running or:

2. Use existing or new 13.5's and rewire for 50 amps to allow for both units to run simultaneously.

My preference is to replace the units with 15's and be able to run them both on 50 amp service.

Re: the power reel question -

I have a power reel that is connected to my Energenius the is located in the port aft section of the coach along with the fresh water hose. It is configured for 30 amps but I have a 50 amp adapter on it that I use to receive 50 amp service. Is that what you are referencing?

Thanks

thenewkid64 · 07-04-2005, 04:42 PM

Quote:

Originally Posted by Nick Danger

Re: the power reel question -

I have a power reel that is connected to my Energenius the is located in the port aft section of the coach along with the fresh water hose. It is configured for 30 amps but I have a 50 amp adapter on it that I use to receive 50 amp service. Is that what you are referencing?

Thanks

Nope,

That 50 to 30 amp converter does not really feed 50 amps to the coach.

A 30 amp plug has a ground a neutral and a 30 amp hot lug.

A 50 amp plug has a ground a neutral and a 30 amp hot lug and a 20 amp hot lug.

The converter just feeds the 30 amp through and has no connection for the 20 amp lug.

To rewire the coach would require replacing the power cord and modifying the way it hooks into the main breaker panel. The cord reel timer spring contacts will not carry the 50 amp feed since there are only 3 contacts so it would need to be removed.

The other way to connect the 50 amp power cord is to wire it into the panel from the gen-set and that way the current systems will protect the ends from becoming energized when you use either power cord.

Nick Danger · 07-04-2005, 06:42 PM

Makes sense how you explained it.

I think I'll replace the units with 15's and take it from there The existing units are 14 years old and just don't produce the cooling they should. Ramping up to 50 amps sounds like something I would like to discuss further with you. Can you PM me your email address? I'm at swright227@earthlink.net

Have you had any experience changing roof top AC's?

Thanks

thenewkid64 · 07-05-2005, 02:23 PM

Quote:

Originally Posted by Nick Danger

Have you had any experience changing roof top AC's?

Why yes I do.......

I have installed a grand total of 3 Ac's. Both on Airstream/Argosy Trailers. One was a R&R the others were cut a hole and start from scratch.

I have had a plethora of experience in disassembling and reassembling the insides of the 70's vintage models......

How can I help?

Chaplain Kent · 07-15-2005, 12:27 PM

Just returned from 12 days in the woods with no AC available. Wonderful trip and did not need the AC at all. However, I would still like to be able to switch from the rear to the front if I am on shore power. My coach does not have a switch- that I know of. Has anyone ever installed a switch?

wb13798 · 07-15-2005, 03:48 PM

i installed a second drop cord for the rear ac . i placed a male/fmale plug after the breaker box under the bed , male plug connected to ac breaker box so you dont frye your self. female plugs to genset and on power cord to out side source. when i want to go to rear ac i plug into the second cord and to the campground power pole. must be 50 amp. second ac is powered by the 20 amp ac plug.. front and rear can run at the same time. and it makes a heck of a difference two 13.5 will make your bones hurt in the middle of summer in austin texas . been there done that. older campgrounds have only 30 amp service, in this case run one or the other but not both. or use a second power pole, or replug and use the genset. this way you dont have to touch the ac wiring panel and reel for the primary ac service.