Another easy question about the AC....

I have a 30 amp service which was enough to run one AC unit on our Bighorn.....with our current unit....can't seem to get the trailer cool..we have two thermostats that appear to be hooked together with 4 zones....do we have to have a 50 amp service for the units to work??? I guess the days of running only one unit are over with......Thanks

Do you have 50 Amp AC plug or 30 Amp AC plug on side of trailer? Is the main breaker on your circuit breaker panel 30 A or 50 A ? Based on your post ti sounds like you have 30A and factory only wired the trailer for one AC unit. A 13,500 BTU roof air conditioner has a starting current of well over 15 Amps, and a running current well over 10 Amps, It might be possible to run two AC on 30 A if you never started them both at the same time and you never ran any large AC load like the microwave, anything with a heating element (hair dryer, coffee pot, electric toaster, electric skillett, etc., and you dont' have electric hot water heater. There are some smaller wall/window units you can browse at Sears, etc. that draw less amps that you might be able to use if could mount in a wall or window some how, that would cause you less problems if your trailer is wired for max 30 amps used at any given time.

When we had our walk thru yesterday..the dealer had the trailer plugged into a 50 amp service....cooling was fine....I get it home into my backyard and plug into a 30 amp service knowing from past experience that I could only run one AC unit...otherwise I would trip the breaker...using that same logic on this one...I've only run one AC unit at a time...whats strange is no matter which unit is on...it will feed both the front & back of the trailer but really struggles providing cool air...I was thinking it would be the same as our previous Bighorn....run the main unit and cool off the living room area or run the bedroom unit and only cool that area....

whats strange is no matter which unit is on...it will feed both the front & back of the trailer but really struggles providing cool air...I was thinking it would be the same as our previous Bighorn....run the main unit and cool off the living room area or run the bedroom unit and only cool that area....

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Sounds like your 2013 Key Largo has the new "Whisper Quiet" A/C design. I think it's a common set of ducts and the units are probably designed to run cooperatively to cool the entire trailer.

If you are just trying to cool the rig while at home (not living in it using other stuff), you might just barely be able to run both. Keep in mind that the Power Converter uses a couple of amps, so you will be close to tripping breakers with both units running.

The problem is the startup amps. Once they were both running, you would be well below 30 with enough to spare for the power converter. Your power converter could be drawing as much as 700 watts (assuming 55 Amp converter) if your batteries are charging, but this will be the actual 12 volt load plus 20% or so for conversion loss if batteries are at full charge. You might be able to flip off the breaker to the power converter, get both ACs started up, then flip the power converter breaker back on. The amps go down once the compressors on the ACs are started up and running. If just the two AC trying to start together trips your house 30A breaker then you may have to use your circuit breakers to switch off one AC unit at the breaker panel, then wait 30 seconds after the other AC has started before flipping the breaker back on. Good luck.

The simple answer is yes, you need 50 amp service to run both A/C's. You might get lucky and get both running at once, but when a compressor cycles or anything else uses some power, you will trip your house breaker.

Close the bedroom vents. Open the max cool vent on the main a/c.

Agree that moving up to 50 Amp Receptacle is your best path forward. 50A RV service is actually two 50 Amp 110 Volt Feeds one on the L1 side of your breaker panel and other on L2 side, so its actually more than 3X more power than the 30 Amp feed can provide. Very high end RVs can even run some things on 220V inside them when running on 50A shore power or generator, most home AC units use 220 Volt so that more volts and less amps feed the unit outside so smaller wire size can be used. But, yours will not have anything in it that uses 220. With a common neutral and ground, using 4 wires from your power panel. Your current 30 Amp uses one breaker space the 50 Amp will use a two breaker space circuit breaker same as what an electric stove does. Must use at least 6 ga for eadh wire most use 4 ga wire since its total length to the RV is always more than 50 feet in most cases between the RV cord and the wire from the breaker box to the outlet. It is CRITICAL that you ensure the receptacle is wired correctly BEFORE you plug in your Bighorn. In particular the white (Neutral) MUST be good and in the right place on the receptacle and the ground must be in the right place and good. Good luck.

Note if the white (Neutral) is not right i.e open then some parts of the RV will get more than 110 V (worst case 220 V) and some parts will get less than 110 V. As you might guess this makes bad things happen to the converter, microwave, etc.

Thanks for the responses..guess I'll upgrade to a 50 amp....