A/C tripping breaker need help thanks

[Sardis22]

Hi, sorry if this has been asked before but I am getting very frustrated. I have two Coleman Mach airs 13500 btu. They are running on a onan 5500 gold the front air works perfect on shore power our geny. The rear air trips the geny breaker after about five minutes. It does blow very cold. It also trips the house breaker when on shore power after about ten minutes. I replaced the cap and it is very clean in side and out. I checked the voltage and I am getting 119 volts when both airs are running on geny then the rear air just trips the breaker. Any help would be great fully appreciated. Thanks very much.

[terry735001]

the breakers may be old after a few say 10 trips it takes a lower load to trip them again
would look at your / tighten wiring lugs / wire nuts / on breakers
some where the amps well be making wiring hot
i some times well hold/touch wire nuts / said wiring to see whats getting hot

[94-Newmar]

Try running the rear AC on FAN only for awhile. If it doesn't trip the breaker on the genset (if running on genset) or the house breaker (if plugged into shore) then try again running the AC and compressor. I suspect you have a compressor motor in that AC unit heading south and drawing too much amperage. Does your coach have a power display panel to show you the amps being drawn? Do you have the means to meter the amp draw?

[menoble]

X2 on the southbound compressor. Your nameplate probably looks something like this one. Put an ampmeter on it, you shouldn't be pulling any more the the max circuitry amps, if you are, it won't last too much longer.

[Sardis22]

I am going to check the amp draw this afternoon thanks where is the best place to clamp on to check the amp draw.

[Sardis22]

How do I know if I have a transfer switch.

[menoble]

Originally Posted by Sardis22

I am going to check the amp draw this afternoon thanks where is the best place to clamp on to check the amp draw.

Ideally, where the hot wire exits the circuit breaker, but probably where ever you can get to it will have to do. Safety first.
A weak run capacitor will give you grief too. Rule out the cheap and easy stuff before assuming a worst case scenario.
Two 13.5 A/C units on one 5500 gen seems a little excessive? And are both A/C on the same 'house' breaker or separate?

[Sardis22]

They are on sperate breakers

[ronspradley]

Do you have a 30amp coach or a 50amp coach?

If you run rear AC only, without running front air, will it still flip the breaker?

ronspradley

[PlayItForwrd]

I just went thru this with our houseboat, probably the exact same Coleman unit, it started tripping the breaker early this year. I bought a new breaker, it tripped quicker than the 25 year old one did. Sad, because it blew ice cold air too. Last weekend we replaced it, just in time too, because it started tripping the breaker just turning the thing on.

Our new AC, which is hardly used Duo Therm that's been sitting in a storage shed for 8 years (free, can't beat that!) works fantastic, and no breaker tripping...

Add me to the list of "your compressor is shot" opinions...

[gatorcq]

Check your wire connections and replace the breaker. That will eliminate.

[FTInMyDreams]

Good advice given so far. I had the same problem but mine was not tripping as soon as yours. When I went up on the roof and checked the unit I could hardly spin the fan by hand. I used lubricant to loosen and it worked for a while but went back to trying to freeze up. Since the unit was cooling fine I replaced the motor and no problems since except I ended up having to also change the motor on the other unit. Lesson learned when not using motorhome make sure to add routinely running the a/c and fans to maintenance.

[Sardis22]

I am at my rv spot and it is tripping the house breaker after about 10 minutes looks like I am in for a new one I am going to check everything u all said and then I will see