Two Air Conditioners

[trukdoc]

When I ordered my Mountaineer 328RLS I went down the options list and amongst other things, I ordered the second A/C. Now that I have the second A/C as set up by the factory I cannot run both A/C units at the same time. I had assumed that It would have been 50AMP service considering everything electrical in it. Not only is it 30 AMP but 50AMP is not even available. Keystone engineers need to get it together. I have fixed the problem my way.

[Fordzilla]

I would have thought it would be 50 amp also. In most cases even if the trailer just has the prewired for 2nd A/C it is set up with 50 amp. Maybe it's a Mountaineer thing? Mine was pre wired for the 2nd a/c and it already had 50 amp service. I know last weekend I was able to run both A/C's with 30 amp service as long as I didn't have everything else running. I used them both for 5-6 hours until the trailer got cooled down, then switched to just the main one. You'll be glad you got the 2nd one on the really hot and humid days of summer.

[richfaa]

The things you can learn on this forum..Why in the world would Montana have a two A/C option if you can not run both of them at the same time..I think the intent of having two would be so you CAN run both of them. Turning everything else off to run two is NOT a solution to the problem..Another HUGE question on our "how come " list when we tour the factory.

[ronstan]

I don't have the second A/C nor is it wired but thought that you had to have 50 amp connection to run them both. Maybe someone who has more ideas about that.

[Bill DeMeulle]

I have the two A/C units on my Montana 3280RL,when I added the second one they told me it had to be re-wired to run both at the same time. I questioned them & Keystone re: if you tell me it is pre-wired why do I am I restricted to only run one at a time? Their response you only need to run the main one during the day and the one in the bedroom at night. It did not make any sense to me so I payed to have it re-wired. So much for design engineers!

[sreigle]

When we ordered ours I think it said 50 amp service is required if you order the 2nd AC prep. I know our dealer said that. We got the prep but not the second AC. So are you saying the existing wiring for the 2nd AC prep will not allow both to run at the same time? If we decide to add the second AC I'd sure like to know that in advance so I could have it changed. That said, 20 amps of our 50 amp service is supposedly set aside for the second AC, so we have just 30 amps out of that 50 to the rest of the coach including the main AC. So I would think ours is set up to run both at the same time. Maybe not?

[richfaa]

Well I have a lot of questions to ask about A/C when we do the factory tour.We do not plan to order two but will have the pre wire option. Does not make any sense at all to only be able to run one at a time. The one unit in out TT does the job Ok but the fiver will be bigger and layed out different..I thought 50 amp service was standard..am I hearing that 50 amp service is a OPTION???

Just looked ..The Montana Standard list says that 50 AMP IS standard.So if 50 amp is standard "how come" you can't run both at the same time??? what is wrong with that picture???

[Fordzilla]

I know mine was pre-wired for the second A/C and I can run both at the same time. I also had 50amp service from the factory. Like Steve mentioned above I think its part of the 2nd a/c prep package. But I hvae ran both at the same time without problems.

[Montana_2785]

quote:Originally posted by richfaa

[...]I thought 50 amp service was standard..am I hearing that 50 amp service is a OPTION???

Just looked ..The Montana Standard list says that 50 AMP IS standard.So if 50 amp is standard "how come" you can't run both at the same time??? what is wrong with that picture???

Rich,

Our 2002 3575RL brochure clearly states that 50AMP service is an OPTION and that 50AMP service is required (or automatically added) if the second A/C prep is selected.

There has clearly been modifications over the years on how Keystone wires these things. Our "50AMP" service is the most ignorant, backwards piece of ____ I'd ever hope to see. I have one 30AMP leg and a second 20AMP leg instead of two 50AMP legs that you would normally see in a stick house if you had a "50AMP" circuit. As far as I can tell (haven't exhaustively tested out yet) the only item on the 20AMP leg is my non-existant second A/C that I'm wired for. The rest of the coach is on the old 30AMP standby. AND about half the coach is on a single 15AMP breaker.

I understand from other conversations on this forum that this was modified to allow better use of the available power from the 50AMP service outlets. However, it does seem like there are still some screwy wiring plans (or screwed up as the case may be) leaving the factory.

Whoever has the "master" PDI check list might want to update to include tracing the servicing breaker and 50AMP service "side" for each appliance and electrical outlet. Might save some nasty surprises later....

I know that one of the larger items on my List-Of-Things-To-Do is to explore the possibility of rewiring our rig so I can also make better use of available 50AMP service and keep from popping my poor overworked 15amp breaker.

Eric

[sreigle]

Rich, when we ordered our 2003 model, 50amp service was an option but mandantory with certain options as Eric explained. Out of curiosity I looked at the montana website at options and standard items and did not find anything specifically identifying either 30 or 50 amp service. However, in the standards list is says "50-amp detachable, marine power cord", which implies 50 amp service is now standard.

Eric, your electrical setup is the same as ours. I believe it was the late 2003 models that got the better electrical setup. Ours is an early 2003. Drat. I would be very interested in what you come up with in changes to the electrical setup.

[richfaa]

Yes Steve it says that AND 55 amp convertor which would lead you to think that 50 amp service IS standard and it may well be..however how that 50 amps is distributed is another story.I have added that "question" is my ask list for the factory tour AND added "run both A/C while doing the PDI" to the PDI checklist.

[Montana_2785]

quote:Originally posted by richfaa

Yes Steve it says that AND 55 amp convertor which would lead you to think that 50 amp service IS standard [...]

Rich, take care to realize that that is 55AMPs at 12V.

That will be about 660 watts. Taking that to 120V gives us (using too simple a math and fudging in a 90% efficiency in the converter) about 6AMPs AC if your converter is running full bore.

Eric

[Montana_2785]

quote:Originally posted by sreigle

[...]Eric, your electrical setup is the same as ours. I believe it was the late 2003 models that got the better electrical setup. Ours is an early 2003. Drat. I would be very interested in what you come up with in changes to the electrical setup.

Steve, I will let you know what I find. During cold weather while I was running electric heat I kept popping breakers left & right. It really honked me off so I WILL be taking a careful look at the possibilities.

I'll take my time to see what I have and the access points for electric that are available. Then I'll map out what I think we want so the two of us can go over it. I'd really like to balance some of my load over the second side of the 50AMP supply so I can properly take advantage of the extra power AND convert the 30/20 amp service to true 50/50 amp service.

Plus, I'm slowly going forward with my plans for an inverter so I'll want to have a number of loads automatically excluded from the inverter in case of an unanticipated switch to battery power (power out during a storm while we are not there...) I would like to exclude the water heater electric element, refrigerator electric element, key outlets that we will use electric space heaters with, A/C(s), etc.

I suspect that it will be fun trying to map all of this out onto the accessible parts of the wiring.

Plus, I'll need to find and install a larger breaker box. There are so few breaker positions that came from the factory it isn't funny.

The biggest problem is finding the time to do all of this

BTW: Speaking of wiring in general... last week when I fixed my grey tank leak I noticed that the nuts that hold the grey tank sensor wires on the sensor studs were loose and almost ready to fall off. After tightening them the level readings for that tank almost seems to work! I guess I should look at the wiring for the sensors for the rest of the tanks.

Eric

[sreigle]

Eric, we run two electric heaters in winter, too, but one has to be on low if the other is on high. Also, the one upstairs is plugged into the outlet on the closet wall, under the tv. That's one of the few not on the gfci circuit. The one in the downstairs area is plugged into the gfci circuit. It is very frustrating popping breakers. Clocks have to be reset. VCR programs to tape shows have to be redone. Etc.