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Looking for 2 AC's with 30 amp tips

estesbubba
Explorer
Explorer
Our new fifth wheel has 2 15K AC's and I know you can't run both when at a 30 amp site. The 2nd AC is directly above the bedroom which is in the front of the trailer. So is it best to run the main AC during the day then switch to the bedroom at night? Both units are hooked into the ducting but the main doesn't blow much air in the bedroom. Also is it OK to run the main AC and run just the fan on the bedroom unit? When I do that it blows more cold air in the bedroom. They are both Coleman-Mach units.
--Bubba

2008 Keystone Cougar 291RLS 5er
2015 Ram 3500 SRW Crew Cab with 6.7L Cummins

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retispcsi
Explorer
Explorer
We just avoid 30 amp sites. Decided a while back. Seldom have an issue.
2015 Mobile Suites 38 RSSA. 2014 Ram CC DRW 4x4 60 gal RDS Aisin 4:10.
DW, Shadow, Remington and Ron. Living the good life till the next one arrives.

1971duster340
Explorer
Explorer
Our coach doesn't have an amp demand issue, but my philosophy is set one thermostat at 70F in the area we're using and the other stat at 73F...primary/secondary zones. The ducting is tied for both units. All things considered, it stays nice until it gets above 90F outside. I use the same plan, different temps, with the heat pump.
Greg
N5LFH
2007 Chariot

Tiger8r
Explorer
Explorer
estesbubba wrote:
Our new fifth wheel has 2 15K AC's and I know you can't run both when at a 30 amp site. The 2nd AC is directly above the bedroom which is in the front of the trailer. So is it best to run the main AC during the day then switch to the bedroom at night? Both units are hooked into the ducting but the main doesn't blow much air in the bedroom. Also is it OK to run the main AC and run just the fan on the bedroom unit? When I do that it blows more cold air in the bedroom. They are both Coleman-Mach units.


Yes you can do what you have stated. We do the same thing if we have to use a 30A service.

Cummins12V98
Explorer III
Explorer III
I had no problem running both AC's on my 07.5 Mobile Suites on 30A park power. I did turn the water and frig to propane.
2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

Bumpyroad
Explorer
Explorer
my MH had a decent EMS and it would run the two ACs on 30 amps. alternated starting, etc.
bumpy

RckyMtnVia
Explorer
Explorer
Over the years I have seen some 5th wheels with a heavy duty extension cord from the inside of the rv plugged into the electrical post to get an additional power source. It may not be enough to run a 2nd AC, but may help with other appliances. I did this with my Winnebago Via which is 30amp, and my wife uses the extension cord for her hair dryer when we are running the AC.
2022 Forester MBS 2401B

GPG52_
Explorer II
Explorer II
We have a Cougar 327 RES with the two AC configuration as well.
What we found works for us (subject to weather) once you have the unit cooled down is using the bedroom AC only. With the bedroom door open it allows the cool air to flow down to the living area, maintains it comfortably, reduces noise level to have a conversation, watch TV, listen to the radio etc. If needed we open up the kitchen ceiling vent to allow the hot/warm air out as the cool A/C air fills the room. On super hot days in a sunny site we run both A/C's if we have 50amp power. I never run both A/C on 30 amp as I have been told that grey power could harm the A/C unit. As noted by donn0128 switching the appliances to propane is recommended.
GPG 🙂
2014 Ford F250, 6.2L, 4.30 Ratio, 6 speed
2014 Cougar (by Keystone) 327 RES

Walaby
Explorer II
Explorer II
I can run my two 15K A/C's on 30 Amp. Gotta switch fridge and HW heater to propane to do it, but that's fine.

Each A/C takes 12.5Amps. Fans kick on first, taking 8 amps each. Then compressor kicks on and it's running 12.5 amps each. That's only 25 Amps of the 30.

Mike
Im Mike Willoughby, and I approve this message.
2017 Ram 3500 CTD (aka FRAM)
2019 GrandDesign Reflection 367BHS

KD4UPL
Explorer
Explorer
You might be able to run both. Try it. The worst thing that will happen is you will trip the main 30 amp breaker. If the breaker doesn't trip then you're fine. I would think you would want the WH on gas and nothing much else on for this.
Run 1 AC and the fan? Sure. The fan pulls next to nothing compared to the AC compressor.
As the compressors cycle on and off at different times they might not be on much at the same time anyway.
There are energy management units available that will send power to one AC for a while and then send it to the other for a while. This allows both of them to run some. I don't know how much these cost.

donn0128
Explorer II
Explorer II
If your going to try to use AC on a 30A circuit, switch the refer and water heater to gas only. A 15K AC will require approx 20A starting. So if something else was running at that time you could end up burning out something due to brown out.

pianotuna
Nomad III
Nomad III
Consider upgrading to a 3000 watt Magnum hybrid inverter/charger with load support. That may allow you to run both air conditioners at once on a 30 amp supply.
Regards, Don
My ride is a 28 foot Class C, 256 watts solar, 556 amp-hours of Telcom jars, 3000 watt Magnum hybrid inverter, Sola Basic Autoformer, Microair Easy Start.