Mitsubishi Electric PUZ-WZ50VAA Service Manual page 36

Check code Abnormal points and detection method
Outdoor fan motor
Abnormal if rotational frequency of the fan motor
is not detected during DC fan motor operation.
Fan motor rotational frequency is abnormal if;
U8
• 100 rpm or below detected continuously
(4400)
for 15 seconds at 20
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
Refer to "9-7. FUNCTION OF SWITCHES, CONNECTORS AND JUMPERS".
codes
Overvoltage error
• Increase in DC bus voltage to
WZ50/WZ60/80V : 430V
01
Undervoltage error
• Instantaneous decrease in DC
bus voltage to
WZ50/60/80V : 200V
02
U9
(4220)
Input current sensor error
• Decrease in input current
through outdoor unit to 0.1A
only if operation frequency is
04
more than or equal to 40Hz
or compressor current is more
than or equal to 6A.
Abnormal power synchronous
signal
• No input of power synchronous
signal to power circuit board
• Power synchronous signal of
44 Hz or less, or 65 Hz or more
08
is detected on power circuit
board.
OCH816
Failure in the operation of the DC
fan motor
Failure in the outdoor circuit control-
ler board
°C
or more outside
Abnormal increase in power source
voltage
Disconnection of compressor wiring
Defective outdoor power circuit board
Compressor has a ground fault.
Decrease in power source voltage,
instantaneous stop
Defective converter drive circuit
in outdoor power circuit board
(WZ50V,WZ60V,WZ80V)
Defective 52C drive circuit in outdoor
power circuit board
Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board
(WZ50V,WZ60V,WZ80V)
Power circuit failure on DC
supply for 15 V DC output on
outdoor controller circuit board
(WZ50V,WZ60V,WZ80V)
Defective ACCT (AC current trans)
on the outdoor power circuit board
Defective input current detection
circuit in outdoor power circuit board
Defective outdoor controller circuit
board
Distortion of power source voltage,
noise superimposition.
Disconnection or loose connection of
earth wiring
Disconnection or loose connection
of CN2 on the outdoor power circuit
board /controller circuit board
Defective power synchronous signal
circuit in outdoor controller circuit
board
Defective power synchronous signal
circuit in outdoor power circuit board
Cause
Check or replace the DC fan motor.
Check the voltage of the outdoor circuit
controller board during operation.
(When the failure is still indicated even
after performing the action 1 above.)
Check the field facility for the power sup-
ply.
Correct the wiring (U . V . W phase) to
compressor. Refer to "9-7. FUNCTION
OF SWITCHES, CONNECTORS AND
JUMPERS". (Outdoor power circuit board).
Replace outdoor power circuit board.
Check compressor for electrical insula-
tion. Replace compressor.
Check the field facility for the power sup-
ply.
Replace outdoor power circuit board.
(WZ50V,WZ60V,WZ80V)
Replace outdoor power circuit board.
Check CN2 wiring.
(WZ50V,WZ60V,WZ80V)
Replace outdoor controller circuit board.
(WZ50V,WZ60V,WZ80V)
Replace outdoor power circuit board.
Replace outdoor power circuit board.
Replace outdoor controller circuit board.
Check the field facility for the power sup-
ply.
Check earth wiring.
Check CN2 wiring.
Replace outdoor controller circuit board.
Replace outdoor power circuit board.
36
judgment and action
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