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Compressors

Compressor Does Not Run

QuestionsCauseRemedy
What is the temperature inside of the box? What is the box control temperature setting?No cooling neededNone. Wait until cooling is needed.
Where is the temperature being sensed?Control off, due to cold location.Move temperature control bulb to warmer location.
Have you checked the liquid line solenoid to make sure it is open? Does the coil have power?Liquid line solenoid will not open.Repair or replace coil.
Have you checked voltage and amperage to compressor?Low voltage or amperage.Increase voltage and or amperage to nameplate specifications
Is main switch closed?Motor line open.Close start or disconnect switch.
Have you checked the fuses?Fuse blown.Check electrical circuits and motor windings for shorts or grounds. Investigate possible overloading. Replace fuse(s) after fault is corrected.
Have you checked wiring connections?Improperly wiredCheck all wire junctions. Tighten all terminal screws.
Have you checked your wiring?Improperly wired.Check wiring against diagram. Make changes as necessary.
Have you checked your contractors & relays?Contractor or relayRepair or replace contractor or relay.
Will unit restart after time?Tripped overloadOverloads are automatically reset. Check unit close when unit comes on line for cause of overheating.
Are all controls functioning properly?Control stuck open.Repair or replace control.
Are all safety devices in a reset mode?System shutdown for safety device.Determine cause and type of shutdown and correct it before resetting the safety switch.
Have you checked start capacitor?Start Capacitor (see section IV)Replace if necessary.
Have you checked run capacitor?Start Capacitor?Replace if necessary.
K & L. Does compressor pullPiston stuck.K & L. Replace compressor.

 

Compressor Loses Oil

QuestionsCauseRemedy
Have you checked oil charge?Insufficient compressor oilAdd oil to proper level
Have you checked refrigerant charge?Shortage of refrigerantRepair leak and recharge
Have you checked pressure drop across coil?Evaporator designChange coil to get higher gas velocity
Was proper oil gas ratio met at start-up?Gas-oil ratio lowAdd 1pint oil for each 10 pounds of refrigerant added to factory charge
Have you checked expansion valve?Plugged expansion valve or strainerClean or replace
Do you have traps near evaporator and in vertical risers as necessary?Oil trapping in linesAdd traps as needed. Drain tubing toward compressor
Does unit short cycle?Short cyclingRefer to section II
Have you checked your evaporator superheat?Refrigerant flood backChange location of expansion valve bulb or adjust valve to return wet gas to compressor