Running AC and Fan on Second AC - 30 amp

I have a 50AMP TT, but I wanted to be able to incorporate the 20 GFCI receptacle at state parks (without tripping the GFI) or use both the 50 and 30 amp connections and this is the only SAFE way I found. I wanted to run both AC's and a microwave and not worry if the ice machine kicked on too. Some homemade brews could be a disaster waiting to happen if the park is wired with multiple phases feeding the plugs. To me, it was well worth the money and time to install this setup. I get 50 amps of service on a 30 amp site or 70 amps on a 50 amp site without straining any components! The JTB automatically "removes" the main A/C from my main panel when the JTB is plugged in so it doesn't count towards my main panel amperage draw. When the JTB is not plugged in, the main A/C is still part of the main panel. It's a "smart" set of automatic relays that won't trip the GFI.

Here's is my JTB Power Solution System installed in my Denali 266RL 34' TT. I also have a Progressive Industries EMS on both the 50AMP Main Panel service and the 30AMP (Technically 20AMP) JTB service. I did not opt for the install kit as I intended to use a 30 amp twist lock power inlet to match my 50 amp main inlet. Also I was running short #10 wires, so the install kit is not pictured. I also purchased the yellow 30to20 amp adapter by Marinco (#126A) for adapting the 30A cord to the 20 amp GFI receptacle.

I also chose to add a receptacle to my JTB box which can be used only if the main A/C is turned off at the thermostat. I chose to "JTB" my main A/C rather than my second A/C because that is the ducted unit that we will always be using. It also is the larger unit and pulls more amps, so I isolated it to the JTB which frees up more available amps on the main 50 amp panel for the microwave, uline ice maker, hair dryer, and other appliances. If I did the bedroom AC on the JTB then I am limiting the amount of time that I actually benefit from the JTB. Haven't been camping as I just finished the install today, but connected to power at home and everything works as expected.

Here's the slideshow photos:
http://s544.photobucket.com/user/knowles2424/slideshow/JTB

Your RV may have a safety switch that prevents you from even attempting to run a second AC on 30 amps. I had a MH that was setup that way. Couldn't even run just fan on the bedroom AC when the front AC was running only fan.
Some RV's have an energy management system that will allow 2 AC's to run on 30 amps by sheding the load from one high use item to another and alternating their use so you don't over load the 30 amp circuit.

If the park has good power and you minimize other use I have run two 13.5KBTU A/Cs (Carrier Air V's) on 30 amps for like half an hour,, Monitored current draw and the units, which had JUST been cleaned, (This is the 2nd time I did it) were drawing exactly their rated consumption of 13.5 amps each (27 total) per the clamp on meter.. The first time I did it they were brand new and thus clean.

IF the park's power is a touch anemic (Many are) no joy doing this.

But one A/C and the fan on the other.. Should work be no tribble at all since the fan motor is at most 5 amps and likely closer to 3.

HOWEVER,,, if you have ducted air.. You will be fooling yourself as one room (The Fan only room) will not be receiving cold air. If you have non-ducted air, then go for it.


now: How to cool both ends with only 30 amps .....

I have a lovely fan here It is about a 10" box fan not at all unlike an Endless Breeze save for one thing.. The price.. As I recall it was 20 or 30 bucks, Runs on 12 volt with an adapter or lighter plug.. Got it at Flying-J or Pilot (Pilot in my case) remember to use your loyality card so you score points.

Old-Biscuit wrote:
Put fridge on propane
Put water heater on propane
Don't use microwave

15K A/C unit will pull roughly 16-17 amps

x2 RV A/Cs draw anywhere from 12-16 amps when it is in its running mode. There is a condition that occurs when the unit starts up called in-rush current. The A/C compressor being hard to kick over on head pressure will briefly draw in excess of maximum rated amps until it gets running, But, as someone else said, as long as the 2 units try to start at once. The breaker may trip.

The compressor is what draws the big amps. Just using the fan will only draw a one or two amps. No problem there.

Put fridge on propane
Put water heater on propane
Don't use microwave

15K A/C unit will pull roughly 16-17 amps

Is the compressor what draws more amps or does just running the fan draw a lot of amps as well. We could probably be fine with one unit running but having the bedroom fan on at night would just help circulate the air. tks

If you stagger the start you could be able to run both. As long as both compressors don't try and start at the same time it is doable.

Yes. I actually can run both my ACs on 30 amps but not much else.