28
Problem
Check Point
Probable Causes
Abnormal running
noise
Flooded-start
During off cycle, liquid refrigerant migrates to the compressor and
mixed with lubricant oil
Refrigerant overcharged
Piping
Resonance vibration occurs
Compressor
Electromagnetic noise of motor
Lack of oil in the compressor
Worn or broken components inside of compressor
Contaminations mix in compressor
Reverse rotation of compressor
Feet of the compressor touch the system base
Compressor runs
but with poor
cooling effect
High discharge
pressure
Non-condensable gas(or air) mixed in system
Refrigerant overcharged
Condenser fan failure
Dirty or blockage of condenser coil
Short air cycle
Low discharge
pressure
Insufficient refrigerant in system
Leakage of refrigerant
Too low ambient temperature
Large air flow through condenser
Liquid refrigerant flooding back
Worn compressor
High suction
pressure
Too high of heat load
Poor heat insulation
Too low superheat setting of expansion valve
Malfunction of expansion valve
Incorrect installation of temperature sensor
Defect compressor
Low suction
pressure
Too low of heat load
Insufficient refrigerant charge
Dirty or iced evaporator coil
Blockage of expansion device
Blockage of refrigeration circuit or leakage of refrigerant
Compressor
Frosted/dew
------
Improper size of expansion valve
Too low heat load
Smelly
------
Large amount of refrigerant leakage
Overheating of electronic components
Overheating of compressor shell