Heat Pump Compressor: Bad Run cap and start assist

Discussion in 'HVAC' started by y2k600f4, Mar 4, 2013.

  1. Mar 4, 2013 #1

    y2k600f4

    y2k600f4

    y2k600f4

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    Hello,

    I was hoping someone could provide some insight. I noticed yesterday that my outside unit (both compressor and fan) were not working. Breaker was tripped...heat was working of aux ht (coils) which will run up my electric bill.

    I was trouble shooting and I turned on the breaker and blew the start assist device on the compressor (PTCR: Positive Coef Resistor Goddman B11416-70 (-71 replacment)). I removed it form the circuit hoping that the 45uf run cap for the compressor would be sufficient for starting; the fan worked fine but the compressor was not starting.

    I removed the run cap (45/5) and checked the caps (fan was fine a t ~5 uf; compressor cap 0 uf: open circiuit; that explains why the compressor was not running without the PTCR !

    Just purchased a replacement PTCR and a run cap from my local HVAC supplier (PTCR is expensive). My question is what could of caused my problem ? My guess is that the compressor run cap shorted throwing the breaker. Upon turning on the breaker it both blew the PTCR and the compressor cap (now open circuit). I probably should test the resistance of the compressor winding ? Thanks in advance.
     
    Last edited: Mar 4, 2013
  2. Mar 6, 2013 #2

    keepinitcool

    keepinitcool

    keepinitcool

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    Hi y2k600f4,

    Definetely test the resistance of the compressor windings (test each terminal to ground, test terminal to terminal, etc.). Also check your wiring over to make sure nothing rubbed through and came in contact with the heat pump cabinet. Also possible a couple wires came in contact with one another that shouldnt have. Ohm out everything you can. Just a few things to check before throwing the new (expensive) parts in and having the same problem occur.
     

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