Refrigerant Floodback
What To Look For:
• Air Cooled Compressors
• Worn pistons and cylinders
• No evidence of overheating
Refrigerant Cooled Compressors
• Center and rear bearings worn or seized
• Dragging rotor, shorted stator
• Progressively scored crankshaft
• Worn or broken ro
Correction:
• Maintain proper evaporator and compressor superheat.
• Correct abnormally low load conditions.
• Install accumulators to stop uncontrolled liquid return.
Flooded Starts
What To Look For:
• Worn or scored rods or bearings
• Rods broken from seizure
• Erratic wear pattern of crankshaft
Correction:
• Locate compressor in warm ambient or install continuous pump down.
• Check crankcase heater operation.
Slugging
What To Look For:
• Broken reeds, rods, or crankshaft
• Loose or broken backer bolts
• Blown head gaskets
Correction:
• Maintain proper evaporator and compressor superheat.
• Correct abnormally low load conditions.
• Install accumulators to stop uncontrolled liquid return.
• Locate compressor in warm ambient or install continuous pump down.
High Discharge Temperature
What To Look For:
• All rods and bearings worn or scored
• Crankshaft uniformly scored
• Rods broken from seizure
• Little or no oil in crankcase
Correction:
• Correct abnormally low load conditions.
• Correct high discharge pressure conditions.
• Insulate suction lines.
• Provide proper compressor cooling.
Loss of Oil
What To Look For
• All rods and bearings worn or scored
• Crankshaft uniformly scored
• Rods broken from seizure
• Little or no oil in crankcase
Correction:
• Check oil failure control operation if applicable.
• Check system refrigerant charge.
• Correct abnormally low load conditions or short cycling.
• Check for incorrect pipe sizes and/or oil traps.
• Check for inadequate defrosts.
