Gray Cooling Man Air Conditioning Repair Advice
  • Home
  • For the homeowner
  • Safety
  • Theory of heat
  • Refrigerants
    • Refrigeration oils
  • Air conditioning design
    • How the evaporator works
    • How the condenser works
    • The expansion device
  • Operation of the refrigeration system
  • Furnace, Air Conditioner and part manuals
    • Gas Appliance install Manuals
    • Electric Furnace Manuals
    • Oil Furnace Manuals
    • Thermostat manuals
    • Boiler manuals
    • Heat pump Manuals
    • Air Conditioner Manuals
    • Service and Troubleshoot Manuals
    • HVAC Part Manuals
    • Crossover manuals
    • Refrigeration and air conditioning part manuals
    • Heating and Air Conditioning wiring diagams
  • Refrigeration equipment manuals
  • Definitions
  • Furnaces
  • Troubleshoot the air conditioner
    • Compressor problems
    • Outdoor fan problems
  • Refrigeration tools
    • Refrigerant recovery machine
  • Diagnostic problems
    • Electrical diagnostic problems with heat pumps
  • Air conditioning repair operations
    • Refrigerant leaks
    • Recovery, evacuation and pump down
  • Refrigeration repairs
  • Refrigeration accessories
    • Accumulator
    • Refrigeration filters driers
  • Charging the air conditioner
  • Compressor design
  • The A/C compressor disassembled
  • Blog
  • Heat pumps
  • Electric test meters
  • HVAC meter accessories
  • Soldering and brazing
  • Humidity and humidifiers
  • Ductwork design and troubleshoot
  • Electric diagrams training
  • Single and 3 phase power systems
  • Motors
  • Run capacitors
  • Start capacitors
  • Troubleshooting the capacitor
  • Air flow problems with the air conditioner
  • Servicing the air conditioner
  • Lennox manuals
  • Carrier, Bryant, Payne manuals
  • Goodman Manuals
  • Trane gas furnace install manuals
  • Rheem Ruud
  • Fireplace manuals

Air conditioning compressor problems

Picture
The following procedures require the use of a voltmeter and the ability to use it. Potential lethal voltages are used here.  Know your limits.
Compressor problems mostly involve electrical problems with the motor in the motor-compressor assembly.  
The motor can fail in several ways.  

1.  The start winding can be open, in which case if power is available, the motor will not start, the run winding will overheat and the internal overload will shut down the power. 

 2.  The run winding can be open, in which case if power is available, the motor will not start, the start winding may overheat and the internal overload will shut down the power.  If the motor is a PSC, the motor will probably not overheat but just won't start. 

3.  Either winding can be shorted, in which case may not run or may run with excessive amperage which will probably open the circuit protection (circuit breaker or fuse).

4.  Either winding may short to ground, Which will cause the circuit protection to open the circuit, sometimes even if the unit is not calling for heat.  
 
5.  The internal overload may fail open.  In which case, no power will pass through so no amp draw will be seen.  (If power is available at the compressor terminals, and no amp draw is shown, the internal overload may be open due to overheat, the unit must be cooled for the overload to reset.)  This may take up to 24 hours.  
If the overload does not reset, the compressor must be replaced.  
Below is a video on internal overloads.  

Below and in the next video we are we are using an insulation tester to check the condition of the windings of the compressor.
This tool uses high voltage to probe for weaknesses in winding insulation.  
In most cases, the windings will be open or shorted to ground.  The diagnosis then is quite easily done using an ohmmeter.
However, detecting a future failure may be done using the insulation tester.
Determining the condition of the windings can be tested using an ohmmeter or an insulation tester.
Below is a video that demonstrates a test of the windings to determine if they are at risk of failure soon.

More coming

Proudly powered by Weebly