Wiring for second AC on a Momentum 30G?

[Mevas1970]

Hello,

Looking for some help here. i am adding a second AC to my 2021 Grand Design Momentum 30G. I called GD and they told me everything I need for the install (See attached Photos). I have it all mounted and ready to wire up and I was told the wiring would be straight forward but not looking that way. Does anyone have experience with doing this? I was also told my GD that I do not need a control box for the 2nd AC so not sure how to wire it since i cannot plug it onto a control box.

TIA.

Michael

[ncitro]

Mevas1970 I did the install of a Coleman unit in the front of my Reflection. I'm almost positive mine was included with my ceiling unit. I got all of my parts from rvupgradestore, they were great to deal with.

[ncitro]

Mevas1970 attached is my order confirmation. Obviously the pricing will have changed (mine was probably three years ago), but these were the parts I needed. Note I went with a heat pump as well as additional electric heat, so that'll be an extra part.

[acoleman43]

Hello,

Looking for some help here. i am adding a second AC to my 2021 Grand Design Momentum 30G. I called GD and they told me everything I need for the install (See attached Photos). I have it all mounted and ready to wire up and I was told the wiring would be straight forward but not looking that way. Does anyone have experience with doing this? I was also told my GD that I do not need a control box for the 2nd AC so not sure how to wire it since i cannot plug it onto a control box.

TIA.

Michael

Just curious....I thought the 30G was a 30 amp unit. Is it 50 amp and did it come pre-wired for AC?

[Mevas1970]

Thanks for the comments everyone. The main issue I am having now is figuring out the wiring. I was told I do not need an additional control box for my second ac. The wiring form the ac time box has a plug. Do I cut that off and wire it up?

[Yoda]

Thanks for the comments everyone. The main issue I am having now is figuring out the wiring. I was told I do not need an additional control box for my second ac. The wiring form the ac time box has a plug. Do I cut that off and wire it up?

You have a 30A service per GD so you will need to run a separate line to your distribution circuit breaker box and have it on a separate breaker.. Not sure what you mean by the additional control box as it is run by the thermostat. Also you will probably find it problematic to run 2 AC units on a 30 amp service. A soft start might help, but with both running (if they will even do that on 30A) you wont be able to run anything else, unless you upgrade to a 50A service and put one AC unit on each leg.

If I may ask what is the issue your trying to correct? Is the AC not cooling and what size AC do you currently have?
Just trying to help - I am sure the electrical experts will be along with better answers.

Keith

[Mevas1970]

Yoda Trying to wire the new ac for the front bedroom. It is pre wired from the factory and on its own breaker. The new unit is a Mach3 13500 btu powersaver. The units that were ordered with 2 ac’s run on the 30amp service (main ac 15000 BTU, front bedroom ac 13500 BTU powersaver). My main question is how do I wire the new ac up. See attached photo of the factory wiring. I purchased everything GD said I would need.

[ncitro]

Mevas1970 I'd recommend you reach out to Grand Design and ask for install instructions. I've never seen that timer box before, all the units I've seen prepped for second AC are 50 amp units as Yoda started. In those installs, the control box is part of the ceiling assembly and everything is connected directly to the control box. I assume that timer box somehow makes sure both AC units don't try to startup at the same time (just a guess), if so then that cable must somehow run to the other unit. The yellow cable in your picture is your 12/2 NM (Romex) feed coming from the breaker. The white box on the end is put there so the wires aren't bare in the ceiling.

[acoleman43]

Yoda Trying to wire the new ac for the front bedroom. It is pre wired from the factory and on its own breaker. The new unit is a Mach3 13500 btu powersaver. The units that were ordered with 2 ac’s run on the 30amp service (main ac 15000 BTU, front bedroom ac 13500 BTU powersaver). My main question is how do I wire the new ac up. See attached photo of the factory wiring. I purchased everything GD said I would need.

Does this help???

[Mevas1970]

acoleman43 thanks but i have a different ceiling assembly

[Yoda]

Yoda Trying to wire the new ac for the front bedroom. It is pre wired from the factory and on its own breaker. The new unit is a Mach3 13500 btu powersaver. The units that were ordered with 2 ac’s run on the 30amp service (main ac 15000 BTU, front bedroom ac 13500 BTU powersaver). My main question is how do I wire the new ac up. See attached photo of the factory wiring. I purchased everything GD said I would need.

Well I just learned something new. Thanks for the photos. I see the experts have arrived so I will sit back and learn from this. Sorry for my confusion
Keith