Mitsubishi Electric PUHZ-RP35VHA4 Service Manual page 45

Abnormal points and detection method
Error Code
Outdoor fan motor
Abnormal if rotational frequency of the 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: 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
(RP35-140V only)
• Instantaneous decrease of DC bus volt-
age
RP35-140V : 200V
RP100-140Y : 350V
RP200/250Y : 400V
• Increase of DC bus voltage to
RP35-71V : 420V
RP100-140V : 400V
RP100-250Y : 760V
• Decrease of input current of outdoor unit
U9
to 0.1A only if operation frequency is
(4220)
more than or equal to 40Hz or compres-
sor current is more than or equal to 6A.
* Check U9 error detail (SW2 all ON).
Refer to 10-10.
Over heat protection
Abnormal if outdoor pipe thermistor (TH3)
detects 70: or more during compressor
Ud operation.
(1504)
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)
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 52C
(RP100-140V)
4 Defective power circuit board
(RP100-140V)
5 Disconnection or loose con-
nection of CN52C (RP35-71V,
RP100-140V)
6 Defective PFC module of out-
door power board (RP35-71V)
7 Defective outdoor converter cir-
cuit board (RP100-140Y)
8 Defective 52C drive circuit of
outdoor controller circuit board
(RP35-140V)
9 Disconnection or loose
connection of CN5 on the
outdoor power circuit board
0 Defective 52C drive circuit of
outdoor power circuit board
(RP100-140Y)
1 Disconnection or loose
connection of CN2 on the
outdoor power circuit board
1 Defective outdoor fan (fan
motor) or short cycle of out-
door unit during cooling opera-
tion
2 Defective outdoor pipe ther-
mistor (TH3)
3 Defective outdoor controller
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
6 Dip switch setting difference of
outdoor controller circuit board.
45
Judgment and action
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 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 Replace power circuit board.
4 Replace power circuit board.
(RP100-140V)
5 Check CN52C wiring.
6 Replace outdoor power circuit board.
(RP35-71V)
7 Replace outdoor converter circuit board.
(RP100-140Y)
8 Replace outdoor controller circuit board.
(RP35-140V)
9 Check CN5 wiring on the outdoor power cir-
cuit board.
Refer to 10-9.
0 Replace outdoor power circuit board.
(RP100-140Y)
1 Check CN2 wiring on the outdoor power cir-
cuit board. Refer to 10-9.
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.
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.
6 Check the dip switch setting of outdoor con-
troller circuit board.