LT-S-(L) Technical manual
8.2
rouble shooting table
Faults
Possible cause
Motor temperature
sensor trip
1. Motor over load, liquid injection solenoid valve fault
2. Coil protection switch fault
3. Electrical system fault
4. Poor motor coil, temperature too high
5. Motor cooling expansion valve failure
Poor motor
insulation
1. Motor connector wet dew
2. Bad motor
3. Poor motor terminal
4. Poor insulation of electromagnetic contactor
5. Acid in the system deteriorates the insulation
6. Long term running at high temperature cause motor insulation
deterioration
7. Frequent start up, coil deterioration
8. Too much water content in the refrigerant.
Motor fail to start
up or switch
1. Inlet solenoid valve failure, which leads to compressor start up at
full load
2. Voltage too low or wrong
3. excessive voltage drop during start up, electromagnet contactors fail
to be adsorbed
4. Motor failure
5. Phase loss or phase reverse
6. Motor protection switch is energized
7. Wrong connection of motor terminals
8. Timer of Y
△
starting malfunctions
9. Overcurrent setting too small or air switch selection selection
inappropriate
10. Poor contact of electromagnet contactors
Abnormal
vibration or noise
1. Bearing damage
2. Liquid compression
3. Friction between the rotors and the shells of the air end.
4. Poor lubrication effect due to oil loss.
5. Inner parts loose