Adding 2nd Air Conditioner

[BB_TX]

Thought this had been discussed before, but search did not find it.
I think I want to add a second AC unit. The one unit keeps the camper cool AFTER it has cooled down. But takes forever to get it cool after traveling for hours on a hot day.
Doesn't seem as if it would be too difficult to install. There is an electrical box just behind the skylight opening which I believe has the wiring already there for the 2nd unit (haven't opened it yet, but wording on the cover seems to indicate that).
Those who have done it, is it a simple do-it-yourself project?
What brand would you recommend? Carrier, Duo-therm, Coleman, other, ?

[Glenn and Lorraine]

This is one of the most recent threads Carrier AC

Here is another talking about 2nd Air Conditioners

The above links should answer most of your questions.

As far as installation, if you are the least bit mechanically inclined with some electrical knowledge you shouldn't have a problem.

Now, even with all that, I am sure there will be plenty of replies to this post with even more good advise.

[BB_TX]

Thanks for those links, Glenn. I think I only did a search in the Additions & Improvements forum.

[sreigle]

Bill, if your rig has the 2nd AC prep option then it has a box with the wiring and also has the framework installed to support it, at the location of the regular vent. If yours has that option there will be a plate on the ceiling along with a sticker identifying its purpose. If you don't have this option, then I doubt the wiring is there and ready to use.

[Art-n-Marge]

Hey BB TX... Thanks to Glenn for posting the "2nd Air Conditioners" topic. There is a lot of the information you seek.

I learned that the 2nd AC prep on my 2006 3500RL consists of the junction box and only the black wire, white wire and bare wire going to the circuit breaker at the IOTA converter to provide power. There are no thermostat wires. Tapping into the existing ducting would be tricky (but doable).

May I suggest you open the blank panel at the ceiling and verify which are wires present? If you have additional wires than the power wires, these are probably for the thermostat and can be used for controlling the new unit from the standard common thermostat control. As an option, then you might want to remove the frame cover for the overhead vent where you will be mounting the new unit and look in the ceiling space for a way to tie into the existing ducting so that the new unit can work with the current unit to help cool the whole rig instead of just the area where it's installed. Otherwise like me, the new unit would just cool the area it's installed and some cool air would trickle down into the main area.

In either case an additional 13,500 BTU of cooling should help a lot. Others have mentioned 15,000 might be overkill and I kinda agree.

[Coronabob]

I am looking at adding the second a/c in our 2009 3000RK. A number of places we stay only have 30 amp power. I was wondering if the front a/c would run on the 30 amp power ? Or is it on a seperate leg of the 50 AMP, so that it doesn't even have power unless it is hooked to 50.
What I would like to able to do is cool the front and not run the rear when on 30 amp service.
Anyone know if this works this way?

[billhoover]

If you do it yourself, how will you get the A/C up on the roof?

[Coronabob]

I will use younger volunteer help. Scaffold on one side. Should work okay.

[BB_TX]

quote:Originally posted by Coronabob

I am looking at adding the second a/c in our 2009 3000RK. A number of places we stay only have 30 amp power. I was wondering if the front a/c would run on the 30 amp power ? Or is it on a seperate leg of the 50 AMP, so that it doesn't even have power unless it is hooked to 50.
What I would like to able to do is cool the front and not run the rear when on 30 amp service.
Anyone know if this works this way?

When you are on 30 amp power with a 50 to 30 adapter, the adapter connects everything together on the one leg of the 30 amp hookup. So that you will still have power to everything just as if you had a 50 amp hookup, just not as much power to draw from.

You can also buy a "Y" adapter that has a receptacle for your 50 amp cord to plug into, a 30 amp plug, and a 15 amp plug. Typically a power post that has a 30 amp receptacle will also have a 15 amp receptacle. The "Y" adapter allows you to connect to both the 30 and the 15 at the same time giving you 30 amps on one hot line and 15 amps on the other hot line. Have never tried one so can't comment on their usefullness.

[Coronabob]

Absolutely a great reply. I had to hit myself on the forehead. DUH. Should have figured that out. Thank you for the info.
We should be sleeping cooler soon.

[lcarter]

You might want to think about a smaller BTU ac. We put a Coleman polar cub 9600 btu unit. It is stand alone with internal thermostat. It does a great job. Both units run well on 30 amp hook ups even on the hot days. It cools down the bedroom very well. One other consideration is the location of your thermonstat for the rear ac. If it is on the steps to the bedroom, the second ac will compete with the setting on the rear ac. It just takes some monitoring to resolve the issue.
Hope it works out for you.

[HughM]

BB TX is right about the "y" connector using a 30 amp box and a 20 amp. However it won't work if the campground has a GFI in the power pedestal. It'll trip the GFI every time. Don't ask me how I know this.
On the other hand they are nice to have and the "Y" connector has come in handy several times.
Hugh

[GregN]

I added the Duo-Therm Penguin Air Conditioner. I forget the BTU, but I think it is the 13,500. It is not ducted and runs on it own. On Hi it blows air down to the living room. Mine works on it own on 30 amp. It also has the option for a heat strip to use it as a heater. It is also low profile as it did add alittle to the height on the front end. I had mine installed at the dealer. Gave me a deal. Also I figured if something was wrong with the instal they would have to fix it. My Monty was pre wired for the second air. On 50 amp with both airs running really cools the coach fast.

[garyka]

I added the second one on mine and helped with the installation and like having two air conditioners,we like using the one in the bedroom on warm nights or afternoon naps,it drowns out noise.We rarely one both.I don't think you can run both on 30 amps.
One thing I have to take into consideration is the height when traveling.The best I can measure is my Monty is 13'4",so I plan my routes with this in mind.

[Coronabob]

Just an update on A/C install. Came back from camping yesterday. Pulled out the vent and cleaned the roof the best I could.
Couldn't find cheap help, so I leaned a 24 ladder onto a ladder standing at the edge of the Monty. Used a rope and pulled unit to top. Install was straight forward. The sensor is installed and the wiring for it was in hole, as well as the communication wire to the rear A/C. The power of course is already there. The ducting is there, so I just opened them up and did the duct taping as required.
Reset the TStat and both zones work perfectly.
Now just to see if I can run the two on 30 amps.
I am strategizing, putting a separate outlet for the 2nd A/C in the garage area, where if needed I could unplug from shore power and plug into a generator. Our Honda 2000 runs the A/C fine.

[Bill and Lisa]

Our "solution" is in this thread
http://www.montanaowners.com/forums/...SearchTerms=AC

[Coronabob]

Thanks for the link. Close to what I want to do. I was going to put an outlet in the basement. This would go to the A/C. Then I would have a cord from power center to plug in when on 50 AMP. Use a cord to plug into second outlet on pole or plug generator into.