Mitsubishi Electric Mr.Slim PUZ-HA30NHA2 Service Manual page 29

Error 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-
mal if;
U8
• 100 rpm or below detected continuously
(4400)
for 15 seconds at 20: [68˚F] or more
outside air temperature
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
Overvoltage or voltage shortage and
synchronous signal to main circuit
Abnormal if any of followings are detected
during compressor operation;
• Decrease of DC bus voltage to 310V
• Instantaneous decrease of DC bus volt-
age to 200V
• Increase of DC bus voltage to 400V
• Decrease of input current of outdoor unit
to 0.5A only if operation frequency is
more than or equal to 40Hz or compres-
sor current is more than or equal to 5A.
U9
(4220)
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
UF
(4100)
Current sensor error
• Abnormal if current sensor detects –1.5A
to 1.5A during compressor operation. (This
error is ignored in case of test run mode.)
UH
(5300)
Overheat protection
Abnormal if outdoor pipe thermistor (TH3)
detects 70:[158˚F] or more during com-
pressor operation.
Ud
(1504)
Case
1 Failure in the operation of the
DC fan motor
2 Failure in the outdoor circuit
controller board
1 Decrease of power supply volt-
age
2 Disconnection of compressor
wiring
3 Defective noise filter circuit
board
4 Disconnection or loose connec-
tion of CN52C
5 Defective ACT module
6 Defective ACT module drive
circuit of outdoor power circuit
board
7 Disconnection or loose connec-
tion of CNAF
8 Defective 52C drive circuit of
noise filter circuit board
9 Disconnection or loose con-
nection of CN5 on the outdoor
power circuit board
0 Disconnection or loose con-
nection of CN2 on the outdoor
power circuit board
1 Stop valve is closed.
2 Decrease of power supply volt-
age
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective compressor
5 Defective outdoor power board
1 Disconnection of compressor
wiring
2 Defective circuit of current sen-
sor on outdoor power circuit
board
1 Defective outdoor fan (fan
motor) or short cycle of out-
door unit during coling opera-
tion
2 Defective outdoor pipe ther-
mistor (TH3)
29
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 facility of power supply.
2 Correct the wiring (U·V·W phase) to com-
pressor. Refer to 11-9 (Outdoor power circuit
board).
3 Replace noise filter circuit board.
4 Check CN52C wiring.
5 Replace ACT module.
6 Replace outdoor power circuit board.
7 Check CNAF wiring.
8 Replace noise filter circuit board.
9 Check CN5 wiring on the outdoor power cir-
cuit board. Refer to 11-9.
0 Check CN2 wiring on the outdoor power cir-
cuit board. Refer to 11-9.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to compres-
sor.
Refer to 11-9 (Outdoor power circuit board).
4 Check compressor. Refer to 11-6.
5 Replace outdoor power circuit board.
1 Correct the wiring (U·V·W phase) to compres-
sor. Refer to 11-9 (Outdoor power circuit
board).
2 Replace outdoor power circuit board.
1 Check outdoor unit air passage.
23 Turn the power off and on again to check
the error code. If U4 is displayed, follow the
U4 processing direction.