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Griffin_sride's avatar
Griffin_sride
Explorer
Aug 18, 2014

A/C tripping breaker

I have a Fleetwood Expedition 36t with 30 amp service and the power management system. Up until recently I've been able to run both a/c's without any problems all day long. Now I can't run both without tripping the 30 amp main breaker. It usually takes a few minutes and when the breaker trips it's pretty warm to the touch. I replaced the breaker to rule out a breaker problem but that fixed nothing. Is is possible that while the a/c is still working and cooling that it will draw more amps as internal parts are becoming worn? I've been told that a compressor will "tighten up" when it's on it's last leg and draw more amps to run but I don't have enough experience with them to know if that's BS or not.

Any ideas or help would be appreciated!

I also plan to check amp draw on front and back unit to see if one is pulling a lot more than the other but I'll have to buy a meter for that. I figure if anything it'll narrow the problem down to one a/c.
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Sep 03, 2014
    Three or 4 things will cause current demands to increase on an air conditioners.

    LOW VOLTAGE has already been covered so I'll leave that here. I will let others discuss things that you may be able to do (like cleaning the plug) to help out here.

    AGE: not likely the culprit but as the motors grow old bearings and such can wear out and increase drag. I do not believe this is your problem

    The last two are very much related.

    HEAT: As the mercury rises, so does the head pressure the compressor is working against and thus its current needs.

    DIRT: epically on the condenser coils.. As they clog with dirt and stuff (Tree Dandruff) air can no longer flow across the fins as well, this results in the coils not coolin off as well and .. Well See HEAT above.

    FACT: one of my 13.5 amp units started tripping its 20 amp branch breaker.. I metered it,, started out at 13.5.. climbed to over 21 just before CLICK.

    I cleaned it

    13.5 and holding.
  • fischer's avatar
    fischer
    Explorer
    Sep 03, 2014
    1 with both AC ' s running note the amps. 28
    2 turn one AC off. note the amps. 16 maybe
    3 turn the other AC off. note the amps. 3 maybe
    mine is 1 it goes up to 3 or 4 if converter is charging the battery
    4 turn breaker for converter/ inverter off and check amps
    good luck
  • C_Schomer's avatar
    C_Schomer
    Explorer
    Sep 03, 2014
    I think the 30a breaker is being run too close to its limit. I've run into that often. I'd try a new breaker and make sure it's HACR rated. Craig
  • Griffin_sride's avatar
    Griffin_sride
    Explorer
    Sep 03, 2014
    After reading Jose's reply about the price of capacitors I'm definitely thinking for $40 I've got nothing to lose on changing all three.
  • Griffin_sride's avatar
    Griffin_sride
    Explorer
    Sep 03, 2014
    Hey guys, I'm still fighting this one. I removed the roof cover and inside cover and cleaned both coils on both units with coil cleaner. I monitored the amp draw before and after the cleaning and saw about 1 less amp draw per a/c unit. The coils were past due for a cleaning. With absolutely nothing else running both a/c's are drawing around 28-29amps. After some time running both front and rear I'm still eventually tripping the breaker.The ECM is working as it should because if I switch the fridge on ac power it will shut off the rear compressor and indicate shed on the control panel for the rear. Last year I burnt up a start up capacitor. I know they have start up and run capacitors. Could the run capacitor be getting weak and causing more amp draw? Would a weak run capacitor be less efficient as the unit gets hotter increasing amp draw causing the breaker to trip?
  • DaHose's avatar
    DaHose
    Explorer
    Aug 19, 2014
    Tripping breakers was the first sign that my capacitors were dying on my AC. Replaced all 3 for $40 and it's worked great since.

    Jose
  • wilanddij's avatar
    wilanddij
    Explorer
    Aug 19, 2014
    Do you have anything else on (HWH on 120V, another TV, coffee pot, hair dryer, fridge) that wasn't on before? Do you have an EMS? Its supposed to drop out one of the AC's when power draw gets too high - maybe its not working.
  • myredracer's avatar
    myredracer
    Explorer II
    Aug 19, 2014
    Low voltage will cause AC units to draw more current. What is the voltage?
  • imgoin4it's avatar
    imgoin4it
    Explorer
    Aug 18, 2014
    Just a question. Are you plugged into the same source of power and if so has anything changed that may cause the voltage to be less now than it was when both were operating as before?

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