Daewoo FRS-U20DD. Service Manual page 45

4)
Troubleshooting
- No Start
PROBLEM
No Compressor Trial
Compressor disconnected from the Inverter
No AC power supply ; or wrong
voltage/wrong
Terminals connected to the Inverter.
No control signal input or bad connection.
Blown fuse (due to previous major failure).
Open compressor motor winding.
Compressor with locked rotor.
(due to mechanical damage).
Dropped, damaged, burnt Inverter.
Inverter on Waiting Time after failed start.
Demagnetized rotor
(only if compressor was previously
connected
directly to the AC power supply).
Compressor positions rotor, But fails to start
Unequaled pressures between discharge
and suction pressures in the refrigerating
system.
Open compressor motor winding.
Too low AC voltage supplied to the Inverter.
Demagnetized rotor
(only if compressor was previously
connected
directly to the AC power supply).
- Malfunction during operation
PROBLEM
Compressor does not run at the speed
selected by the Inverter.
Verify the Compressor Cable connection.
Verify the AC Input Cable connection and measure the AC Input voltage.
Verify the Control Input Cable connection and measure the signal from the
Main-PCB.
Return the unit to manufacturer, replacing it by a new one.
Measure winding for open circuit between all pair of pins on the hermetic terminal.
If one winding is open, replace it by a new one.
Replace compressor by a new one and test for confirmation.
Replace by a new one and test for confirmation.
Wait the necessary time or reset the Inverter disconnecting it from the
AC power supply. The reset time is about 15s.
Replace compressor by a new one and test for confirmation.
Allow the Inverter to equalize pressure between suction and discharge sides.
Measure winding for open circuit between all pair of pins on the hermetic
terminal. If one winding is open, replace it by a new one.
Measure AC voltage to confirm; correct the voltage or change the Inverter
to the correct voltage range (115V or 220V model).
Replace compressor by a new one and test for confirmation.
Too high compression load, with compressor being subjected to a stall
condition. (lower suction and/or discharge pressures for correction).
Too low AC voltage. Check the AC voltage supplied to the Inverter and set it
to the required level or change the Inverter to the correct voltage range.
(115V or 220V model).
No or incorrect control signal.
(check if the correct control signal is arriving at the control Input Connection).
45
ACTION
ACTION