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    VABlake's Avatar
    VABlake Posts: 1, Reputation: 1
    New Member
     
    #1

    Jul 20, 2009, 11:00 PM
    Outdoor a/c unit not working
    Here's the deal... My outdoor unit has tripped the breaker twice in the last 3 months. Seems to only did it on really hot days. Usually, I reset the breaker and it runs again. This time I reset the breaker and reset the outdoor unit switch but it did not come back on. I check voltage in the contactor and it had power. Power was going to the capacitors also. I hear no noises what so ever.

    Will a bad compressor stop the fan motor from going?
    If the compressor is bad will it be worth trying to install a hard start kit? (don't know if they only aid a working compressor or will jump start a dying one also)

    Any clues?? Thanks.
    hvac1000's Avatar
    hvac1000 Posts: 14,540, Reputation: 435
    Heating & Air Conditioning Expert
     
    #2

    Jul 20, 2009, 11:54 PM
    Will a bad compressor stop the fan motor from going?

    NO not unless the run capacitor is a dual purpose one that works with the compressor and fan motor. Then it is possible the capacitor is a problem but not the compressor itself. The compressor and fan are two different items except for the possibility of a common capacitor that was mentioned before.
    I would check to be sure the contactor is pulling in during a call for cooling and I would also check both sides of the contactor when it is pulled in for 220/240 volts between the to legs.
    A contactor can show 220/240 on one side but if the contacts are defective it will not show on the other when pulled in.

    You need to find out what is the problem before you go tossing on a hard start kit.
    A hard start will not cure a dying compressor but it will help a compressor to start if low voltage or high system pressures during startup is a problem. A hard start system takes some of the pressure off the start winding in the compressor. A hard start system only stays in the system for a extremely short time during startup only.

    If you breaker has been tripping especially during hot weather it is a good possibility that the unit is overcharged which will tax the compressor to draw higher current than normal. This in turn will cause the fuse/circuit breaker to trip.

    You may need to contact someone who has more experience than you do for a ON SITE survey of the units problem. Special tools like a Amprobe/gauges/etc are needed to be able to get some readings to help determine what the real cause is. Also a megometer (megger) so you can check the compressor winding resistance to be able to see if any damage has been done to the compressor windings themselves.

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