LB
II
-PLUS Technical Manual
40
If the discharge temperature is too low and the boot lubricating oil temperature of the oil separator is too low, it
will also cause the refrigerant dissolves in the lubricating oil, which will not only cause the compressor bearing
damage, and also make it easier for compressor oil loss. If it is a full liquid system, please check whether the oil
return solenoid valve is opens the oil return according to the set control logic.
Emergency stop
Cut off the power supply and stop the compressor. For major accidents, please cut off the main switch of
the compressor power supply, the whole compressor will be stopped.
Close all the fluid supply valves on the system as soon as possible, and close the suction and discharge
valves of the compressor.
Find out the causes of the failure or accident and eliminate it.
In case of sudden power outage, in addition to close the suction, discharge valve and evaporator supply
valve in time, the power switch should be cut off and the cause of power outage should be ascertained.
4.3
Faults analysis
Faults
Possible reasons
Compressor motor coil temperature protection
jump off
1. The motor load is too large, the cooling is insufficient or the motor liquid spray
solenoid valve is invalid.
2. Coil protection switch failure
3. Poor electrical system or failure
4. Poor motor coil, temperature increase too high
5. Controller of electronic expansion valve failure
Poor motor insulation
1. The wire joint of the compressor motor is humid.
2. Compressor motor failure.
3. Poor compressor wiring terminal
4. The electromagnetic contactor is poorly insulated.
5. Internal acidification of the system, corrosion and insulation
6. The coil is running at high temperature for long time, causing deterioration of the
insulation.
7. Frequent start, coil deterioration.
8. Too much water contained in the refrigerant
The motor cannot be started or switched
1. Voltage too low or voltage error.
2. The voltage drop of the starting voltage is too large and the electromagnetic
contactor cannot be absorbed.
3. Motor failure.
4. Under-phase, reverse phase and lack of phase
5. Motor protection switch activated.
6. Incorrect wiring of motor coil.
7. Bad
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start timer
8. The current setting is too small or the improper selection of circuit breaker.
9. Poor electromagnetic contactor
