Second AC

[Montana_1424]

Well, now that my main AC problem is fixed, I have more questions. I have the wiring for the second AC, and I am thinking about adding it. The past few days, my AC has ran all day long, and only maintained about 85 when it is set for 73. In myrtle Beach, the temp has been aroun 100 with the heat index. So I am thinking the second AC will help that out. My questions are:
1) Is that a correct assumption that I need second AC for those conditiond?

2) Will the same thermostat control both AC units ( is the wiring already in place for this)

Thanks again
Ed

[Fordzilla]

My second A/C is manually controled. I'm not sure if it can be tied into the thrrmostat or not. But with two A/c's you will have plenty of coolin capacity to keep the rig at a more comfortable level. It has been in the upper 90's all week and high humidity and we turned them both on. Within an hour it is very comfortable anywhere in the trailer.

[Bill DeMeulle]

They would not tie in my second A/C it is also manual,Ihad to pay extra for re-wiring. The wiring provided by Montana was only for an A/C that would run alternately with the main. I wanted to run both at the same time,however you can't run both and do any laundry at he same time.

[Northstar]

Ed I am adding a 2nd a/c on Thursday. I will give a report soon after.

[Thunderman]

Ed,
On my 2955RL we have wiring for the second a/c. It does not appear to be connected to the thermostat at all. The wiring is to a 20 amp breaker. I think you would need one you can control with a manual switch.

[trukdoc]

I wired my second AC seperate from the 30 amp system that is standard for the Mountaineer. The idea will work for the Monty's as well. I seperated out the 2 AC unit wires and direct wired the main AC to the trailer wireing. Took out the selector switch that allowed me to run only one at a time. I run a wire through the ceiling down the wall and out by the propane tanks. I put in a receptacle to hook up an extension cord. I then plug in the 30 amp outlet and use a heavy duty cord into the 20 amp outlets. No need to add a circut breaker to the trailer. One is already provided on the 20 amp receptacle on the pole. I can run both AC units at the same time without blowing any breakers. I have effectively converted my Mountaineer to 50 amp without the expense. When it is cooler I do not need to hook up the second cord.

[rames14]

kozzy45 -

I have been told in the past that the A/C unit is designed to reduce the inside temp about 15 degrees with the single a/c. With the outside temp at 90, it will do a good job of keeping it at 75. However, when it's over a hundred, it is difficult. We were in El Paso a few weeks ago and it stayed above 100 each day. We stayed comfortable by turning the a/c from ducted to direct on the ceiling during the day and then in the evening switching back to ducted. We stayed comfortable, but not cold during the day.

For those who have the second A/C prep and the new Duo Temp thermostat from dometic, there is a setting for multiple zones, so you can have the temp set different in each part of the trailer. I believe you would need to run another A/C control wire. Haven't done it, so I don't know what all is involved, but with the second A/C prep and 50 amp service, it shouldn't be too difficult.

[Northstar]

Kozzy45, here is the update on my 2 a/c addition. First my coach Montana 3685FL is wired for an additional ac however I learned for practical reasons it must be set up for manual use. It would be too difficult to operate two remote controls at the same time in the same area. Therefore it is necessary to set it up to operate manually. Also since the 2 a/c was not installed at the factory the a/c is not inducted. However, the 2 a/c works just great and really puts out wonderfully cold air. Since I have a front living room, my 2 a/c is installed near the front of my coach.

[Montana_1892]

hi, we recommend the Brisk Air, Dometic, high effeciency 13,500 with the optional heat strip ... works well and only takes 10 amps.

[prariepoodle]

Kozzy45, We are living in the desart of Nevada and Calif. and with out our second air we could not make it here... The temps. will get up to 125 here and we took the RV in a few months ago and got a colman A/C put on. Now it runs all by its self and not on the Brisk air.. But with the both of them running it stays cool in here. I do have to say that both of them run 24 hours a day... But where we are Elect. is furnished... Thank God...

[trukdoc]

Updating my rewire job for my second AC unit. As previously mentioned I seperated the wireing to the bedroom AC routed a wire out by the propane tanks to hook up a heavy extension cord to 15 amp outlet. Works great. And another reason for doing it like this is when the other half has 30 amps of blow driers, curling irons, and hot rollers getting ready for a wedding on a hot day and the main unit wont stay running without blowing the breaker. The seperate unit is unaffected.

[Redrover98]

I had to put the second a/c in my 04 Montana. We volunteer often down in the Fla keys and this past June the single unit never shut off and it was 79-80 inside. I went with the Dometic Penguin, which is a very low profile and it looks like a small cartop carrier. I saved $200 by installing it myself.The coach was prewired and the installation instructions were good.It only took me a couple of hours.Last week down in the Tampa,Fl area I ran both units on 30 amp service by puting both the fridge and hot water heater on gas.I should have put in the 2nd unit last year.

[trukdoc]

I had tried that as well. I had a selector switch that made it so that one or the other could be used. I simply connected the wires together so that both AC units were hot all the time. The problem was I still was popping the main breaker. I had the main unit upgraded to the 15K unit. Maybe that is the difference I dont know. But my solution of running the wireing seperate is working great.
I think I am going to expand on this and use the new electrical connection to add outlets to the storage compartments without adding load to the trailer.