Mitsubishi Electric PUMY-P100VHM Technical & Service Manual page 38

Display
Meaning and detecting method
Abnormality such as overvoltage or voltage
4220
shortage
Abnormal if any of followings are detected
during compressor operation;
• Decrease of DC bus voltage to 310V
• Instantaneous decrease of DC bus voltage to
200V.
• Increase of DC bus voltage to 400V.
• Decrease of input current of outdoor unit to
0.1A only if operation frequency is more than
or equal to 40Hz or compressor current is
more than or equal to 6A.
Abnormal temperature of heat sink
4230
Abnormal if heat sink thermistor (TH8) detects
85:
4250 (1) Abnormality of power module
Check abnormality by driving power module in
case over current is detected.
(2) Compressor overcurrent interruption
Abnormal if overcurrent DC dc bus or
compressor is detected after compressor
starts operating for 30 seconds.
Over current : 27.5A
Abnormality in the outdoor fan motor
4400
The outdoor fan motor is considered to be
abnormal if the rotational frequency of fan
motor is abnormal when detected during
operation.
Fan motor rotational frequency is abnormal if;
• 100 rpm or below detected continuously
for 15 seconds at 20: or more outside
air temperature
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
Causes
1 Decrease of power supply voltage
2 Disconnection of compressor wiring
3 Defective 52C
4 Defective ACT module
5 Disconnection or loose connection of
CN5 on the outdoor power circuit board
6 Defective 52C drive circuit of outdoor
power circuit board
7 Disconnection or loose connection of
CN2 on the outdoor power circuit board
8 Defective ACT module drive circuit of
outdoor controller circuit board
9 Disconnection or loose connection of CNAF
1 The outdoor fan motor is locked.
2 Failure of outdoor fan motor
3 Air flow path is clogged.
4 Rise of ambient temperature
5 Defective thermistor
6 Defective input circuit of outdoor power
circuit board
7 Failure of outdoor fan drive circuit
1 Outdoor stop valve is closed.
2 Decrease of power supply voltage
3 Looseness, disconnection or converse
of compressor wiring connection
4 Defective compressor
5 Defective outdoor power circuit board
1 Stop valve of outdoor unit is closed.
2 Decrease of power supply voltage
3 Looseness, disconnection or converse
of compressor wiring connection
4 Defective fan of indoor/outdoor units
5 Short cycle of indoor/outdoor units
6 Defective input circuit of outdoor
controller board
7 Defective compressor
1 Failure in the operation of the DC fan motor
2 Failure in the outdoor circuit controller board
38
Check points
1 Check the facility of power supply.
2 Correct the wiring (U·V·W phase) to
compressor. (Outdoor power circuit board).
3 Replace 52C.
4 Replace ACT module.
5 Check CN5 wiring on the outdoor power
circuit board.
6 Replace outdoor power circuit board.
7 Check CN2 wiring on the outdoor power
circuit board.
8 Replace outdoor power circuit board.
9 Check CNAF wiring.
0 The 4220 error history can be confirmed
1 3 4 5 6 7 8 2
with SW1 No.189.
on
12 Check outdoor fan.
3 Check air flow path for cooling.
4 Check if there is something which
causes temperature rise around outdoor
unit.
(Upper limit of ambient temperature is 46:.)
Turn off power, and on again to check if
4230 is displayed within 30 minutes.
5 Check thermistor <TH8> temperature
by micro computer.
6 Replace outdoor power circuit board.
7 Replace outdoor controller circuit board.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor.
(Outdoor power circuit board).
4 Check compressor.
5 Replace outdoor power circuit board.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor.
(Outdoor power circuit board).
4 Check indoor/outdoor fan.
5 Solve short cycle.
6 Replace outdoor controller circuit board.
7 Check compressor.
W Before the replacement of the outdoor
controller circuit board, disconnect the
wiring to compressor from the outdoor
power circuit board and check the output
voltage among phases, U, V, W, during
test run (SW7-1 ON). No defect on board
if voltage among phases (U-V, V-W and
W-U) is same. Make sure to perform the
voltage check with same performing
frequency.
1 Check or replace the DC fan motor.
2 Check the voltage of the outdoor circuit
controller board during operation.
3 Replace the outdoor circuit controller
board. (when the failure is still indicated
even after performing the remedy 1 above.)