Adding 2nd AC to Minnie Winnie 31k

[Jujubeadz]

Hey everyone, looking for advice and someone who has accomplished the task.

So far I have found no one to install.

Need to add a 2nd AC to a 2019 Minnie Winnie 31K, in the bedroom.

I realize being 30amp, I will need to run a 2nd 20 or 30amp outlet and will not run on a generator etc.

However, no dealer or repair facility wants to even attempt the job. It seems easy, as the rear ceiling vent is close to the rear closet and I do not mind the wires being run in a cable hide thing on the ceiling.

Am I'm missing something?

Has anyone done this and had success or failure or is it not viable.

[Ray,IN]

Welcome!
IMO, yes it is entirely doable. You are aware of the 30A limitations, so no issue there. You have a vent in the bedroom so a RV rooftop A/C unit will be a drop-in installation. You already have the wiring figured out, no problem there either.
I would call a mobile RV repairman. The only hard part is lifting an A/C unit onto the roof without damaging anything.

[Eagle5]

Hi Jujubeadz & Ray,
So if I understand your plan correctly, you would run a separate 20 amp outdoor-rated extension cord to the new air conditioner, right? Every RV Park outlet I have seen have both the 30 amp service and the 20 amp service alongside, so you could just plug-in both.
The 50' 12 gauge outdoor-rated extension cord would be hard-wired in with what was the female end to your air conditioner & routed across the ceiling and then down through the closet. Coiling & stowing the excess with the male end in a compartment on the camp-side could be easily accessed when needed. Since you don't involve any other wiring in the motorhome, you can just rely on the 20 amp service outlet's independent circuit breaker.
I like your idea. Please take pictures so we can see the results.
Thanks, Eagle5.

[Ray,IN]

A was thinking about installing this on the RV exterior wall and running the A/C romex directly to this exterior box. https://www.amazon.com/WELLUCK-Water...093547&sr=8-15
Then a 10ga extension cord could be used when the 2 A/C unit was needed.
That would be very safe-labeled of course.

[Eagle5]

Hi Ray,
I like your idea better. 12 gauge romex would lie flatter and be easier to route.
I believe you cannot buy a 10 gauge 20 amp 120 vac extension cord; isn't that right? Would not 12 gauge be sufficient for up to 20 amps?
Thanks, Eagle5

[Ray,IN]

Yes 10ga 15A extension cords are normally used by tradesmen, as they are expensive, just look at them on Amazon. However, I do think you are right about a 12ga extension cord, if they limit the length. a 12ga 50' cord will have a 3.29% voltage drop.
The only difference between 15A and 20A extension cords are the end prong configuration.
The wring in the trailer is 14-2 W/ground, so that's what is needed for the 2nd A/C unit.

[Jujubeadz]

So, an update to the ac. Just purchased a Coleman Mach 15 and and the cables and such. Going to tackle over the next month.

Still trying to figure the best place to mount the plug and run the wire.

Hopefully I’m able to determine where the vertical aluminum studs are in the exterior wall.

I’ll post pics as I go.

[Ray,IN]

Originally Posted by Jujubeadz

So, an update to the ac. Just purchased a Coleman Mach 15 and and the cables and such. Going to tackle over the next month.

Still trying to figure the best place to mount the plug and run the wire.

Hopefully I’m able to determine where the vertical aluminum studs are in the exterior wall.

I’ll post pics as I go.

Rent/borrow a stud-finder, the new models detect metal or wood studs.

[BirchyBoy]

IIRC, the 31K is very similar to the 31BE class A. If not you can ignore this:

I pondered this with our 31BE. My plan was to run the wire into the cabinet over the bed and down the cabinet against the rear wall into the storage in the passenger side. From there, I was going to cross over to the electrical bay and put an electrical box and cable.

My bright idea was going to use a long extension drill bit to run the wire inside the roof foam into the cabinet. Using an appropriate chase between the AC and the cabinet would be a lot easier.

[Jujubeadz]

So I finally installed the 2nd coleman mach 15 in the bedroom. I ran the romex in a tv cable hider and used 3m tape to afix to the ceiling then over to the wall, then ran the cable through the box that hides the toilet exhaust pipe, then drilled a hole in the out side wall where I added a 30amp outlet.

I added the softstart to the ac and it will now run on a 20amp and possibly 15amp circuit.

It keeps my 31k at 72 with both running in the Florida 100d heat and in full sun with no issues.

[Eagle5]

Hi Jujubeadz,
Glad you have it wired-in now, but I am unclear why you wired the 20 amp-rated 12 AWG wire to a 30 amp receptacle. If you do plug into a 30 amp service, you run the risk of a fire if you were to have a dead-short in the RV.
If you are using a 30 amp to 20 amp adapter, then no problem for you, but how do you assure that somebody in the future does not plug into a 30 amp service with your 12 AWG wire which is not rated to carry that load?
Eagle5

[Jujubeadz]

I have the 2nd ac setup on a 30amp plug and cable, then I reduce to 15-20 regular adaptor if a 30 amp is not an option. For example, last week the statepark had both 30 and 50, so the main power was at a 50 reduced to 30 on a surge protector and the 2nd ac was running off the 30amp through a 30amp surge protector.

As far as the romex I ran 10 gauge, as the hope was to always have 30 amp service available.

[Eagle5]

Anytime you use an adapter for a 50 amp service to 30 amp wiring, or a 30 amp service to 20 amp wiring, you run the risk of fire if there is a dead short in the RVs power lines. When we started this back & forth, you were going to use your 30 amp Winnebago-supplied wiring in a 30 amp service, and then add 20 amp rating wiring to use in the 15 or 20 amp service.
The power service poles I have seen have 50 amp and/or 30 amp, and many times also provide 20 amp. I recommend anyone reading this post to not install a 30 amp receptacle to 20 amp-rated wiring.
Eagle5

[Jujubeadz]

I guess I'm confused. I hard wired the 2nd ac using 30amp wire in the rv, which runs to a 30amp outlet on the outside of the motorhome. I then use a 30amp cable to a 30amp box at the parks. I do use a 30amp surge protector.

On the main power for the remainder of the MH, I plug into the 50amp service and reduce with an approved adaptor to 30amps.

99% of the time I have both 30 and 50 options. Am I missing something? I ran the setup by Winnebago support and they said no issues.

[Eagle5]

Hi Jujubeadz,
So sorry; my fault. Yes, now I see you did use 10 AWG wire from the RV receptacle to the plug, which is indeed rated for 30 amps.
As far as the 50 amp to 30 amp adapters, I hope they have a fuseable link that blows over 30 amps of drain.
Thank you for the correction. I had 12 AWG wire on-the-brain!
Eagle5

[Jujubeadz]

I also am running a 30amp digital surge protector on the main unit which will be powered by the 50amp service. And everything is fused at 30amp. So I have redundant fail safes installed, hopefully, that would catch any issues. Thanks Eagle5 for you help, hopefully I can stay cool in the FL sun this summer.

[nandoICUrn]

I have installed one in our last RV. Decided to go with low profile. Installers may not want the Installation, due to the fact that you would be tripping the breaker often if 2 AC were running at same time. And I was told that they did not want the hassle of me coming back for a solution to a problem I created. So I installed myself. I only ran the AC in bedroom. And when we got up, then turned bedroom off and run the second AC. Follow instructions to the T and make sure your power cable is the correct size with a breaker separate form the second AC. Separate thermostat. I contacted the company for roof and frame plans, so it was obvious where to install. Ask for electrical and plbi h lines location just in case. Hope that helps.