Mitsubishi Electric PUZ-HA30NHA5 Service Manual page 30

Check code Abnormal point and detection method
Outdoor fan motor
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 abnor-
U8
mal if;
(4400)
• 100 rpm or below detected continuously
for 15 seconds at 68˚F [20:] or more
outside air temperature
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
To find out the detail history (latest) about U9 error, turn ON SW2-1, 2-2 and 2-6.
Detailed
codes
Refer to "10-10. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
Overvoltage error
• Increase in DC bus voltage to
400 V
01
Undervoltage error
• Instantaneous decrease in DC
bus voltage to 200 V
02
U9
(4220)
Input current sensor error/
L1-phase open error
• Decrease in input current
through outdoor unit to 0.1 A
only if operation frequency is
more than or equal to 40 Hz
or compressor current is more
04
than or equal to 6 A.
PFC/IGBT error (Undervoltage)
• When compressor is running,
DC bus voltage stays at 310 V
or lower for consecutive 10
seconds
20
OCH607
Case
1 Failure in the operation of the
DC fan motor
2 Failure in the outdoor circuit
controller board
1 Abnormal increase in power
source voltage
2 Disconnection of compressor
wiring
3 Defective outdoor power circuit
board
4 Compressor has a ground fault.
1 Decrease in power source
voltage, instantaneous stop.
2 Disconnection or loose
connection of CN52C on the
outdoor power circuit board/
controller circuit board
3 Defective converter drive circuit
in outdoor power circuit board
4 Defective 52C drive circuit in
outdoor power circuit board
5 Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
6 Power circuit failure on DC
supply for 18 V DC output on
outdoor controller circuit board
1 Defective input current detection
circuit in outdoor power circuit
board
2 Defective outdoor controller
circuit board
1 Incorrect switch settings on the
outdoor controller circuit board
for model select
2 Defective outdoor power circuit
board
3 Defective outdoor controller
circuit board
30
Judgment and action
1 Check or replace the DC fan motor.
2 Check the voltage of the outdoor circuit con-
troller board during operation.
3 Replace the outdoor circuit controller board.
(when the failure is still indicated even after
performing the remedy 1 above.)
1 Check the field facility for the power supply.
2 Correct the wiring (U . V . W phase) to
compressor. Refer to "10-9. TEST POINT
DIAGRAM" (Outdoor power circuit board).
3 Replace outdoor power circuit board.
4 Check compressor for electrical insulation.
Replace compressor.
1 Check the field facility for the power supply.
2 Check CN52C wiring.
3 Replace outdoor power circuit board.
4 Replace outdoor power circuit board.
5 Check CN2 wiring.
6 Replace outdoor controller circuit board.
1 Replace outdoor power circuit board.
2 Replace outdoor controller circuit board.
1 Correction of a model select
2 Replace outdoor power circuit board.
3 Replace outdoor controller circuit board.