Outdoor Fan Motor; Compressor Overcurrent Interruption; Current Sensor Error; Low Pressure (63L Operated) - Mitsubishi Electric PUZ-A18NHA4 Service Manual

Abnormal point and detection method
Error Code

Outdoor fan motor

Abnormal if the rotational frequency of fan
motor is not detected during DC fan motor
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
A12, 18, 24N : 420V
A30, 36, 42N : 400V
• Decrease of input current of outdoor unit
to 0.5A only if operation frequency is
U9
more than or equal to 40Hz or compres-
(4220)
sor current is more than or equal to 5A.
• Abnormal power synchronous (zero cross)
signal
• PFC error (overcurrent) when the current
peak of input current increase A12, 18,
24N: 47A (peak)

Compressor overcurrent interruption

(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
UF after compressor starts operating.
(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
w This error is ignored in case of test run
(5300)
mode.
• It's abnormal for 38A the input current or
10 seconds continuous 34A or more.

Low pressure (63L operated)

Abnormal if 63L is operated (under-
0.03MPa) during compressor operation.
63L: Low-pressure switch
UL
(A42N only)
(1300)
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 Disconnection or loose con-
nection of CN52C
4 Defective PFC module of out-
door power board (A12, 18,
24N only)
5 Defective ACT module (A30,
36, 42N only)
6 Defective ACT module drive
circuit of outdoor power circuit
board (A30, 36, 42N only)
7 Disconnection or loose con-
nection of CNAF (A30, 36, 42N
only)
8 Defective 52C drive circuit of
outdoor noise filter circuit board
9 Disconnection or loose
connection of CN5 on the
outdoor power circuit board
0 Disconnection or loose
connection of CN2 on the
outdoor power circuit board
1 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 board
1 Disconnection of compressor
wiring
2 Defective circuit of current
sensor on outdoor power
circuit board
3 Decrease of power supply
voltage
1 Stop valve of outdoor unit is
closed during operation.
2 Disconnection or loose connec-
tion of connector (63L) on outdoor
controller board
3 Disconnection or loose
connection of 63L
4 Defective outdoor controller board
5 Leakage or shortage of refrigerant
6 Malfunction of linear expansion
valve
39
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 action 1 above.)
1 Check the facility of power supply.
2 Correct the wiring (U·V·W phase) to com-
pressor. Refer to 10-9 (Outdoor power circuit
board).
3 Check CN52C wiring.
4 Replace outdoor power circuit board.
(A12, 18, 24N only)
5 Replace ACT module. (A30, 36, 42N only)
6 Replace outdoor power circuit board.
(A30, 36, 42N only)
7 Check CNAF wiring. (A30, 36, 42N only)
8 Replace outdoor noise filter circuit board.
9 Check CN5 wiring on the outdoor power
circuit board.
Refer to 10-9.
0 Check CN2 wiring on the outdoor power
circuit board.
Refer to 10-9.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor.
Refer to 10-9 (Outdoor power circuit board).
4 Check compressor.
Refer to 10-6.
5 Replace outdoor power circuit board.
1 Correct the wiring (U·V·W phase) to
compressor. Refer to 10-9 (Outdoor power
circuit board).
2 Replace outdoor power circuit board.
3 Check the facility of power supply.
1 Check stop valve.
2~4 Turn the power off and on again to check
if F3 is displayed on restarting.
If F3 is displayed, follow the F3 processing
direction.
5 Correct to proper amount of refrigerant.
6 Check linear expansion valve.
Refer to 10-6.