Mitsubishi Electric PUHZ-HRP200YKA Service Manual page 21

Abnormal point and detection method
Error Code
Current sensor error or input current error
• Abnormal if current sensor detects –1.0A
to 1.0A during compressor operation. (This
error is ignored in case of test run mode.)
UH
Low pressure (63L operated)
Abnormal if 63L is operated (under
-0.03MPa) during compressor operation.
63L: Low-pressure switch
UL
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or com-
pressor is detected after compressor starts
operating for 30 seconds.
UP
Case
1 Disconnection of compressor
wiring
2 Defective circuit of current
sensor on outdoor power
circuit board
3 Decrease of power supply volt-
age
1 Stop valve of outdoor unit is
closed during operation.
2 Disconnection or loose con-
nection of connector (63L) on
outdoor controller board
3 Disconnection or loose connec-
tion of 63L
4 Defective outdoor controller
board
5 Leakage or shortage of refriger-
ant
6 Malfunction of linear expansion
valve
1 Stop valve of outdoor unit is
closed.
2 Decrease of power supply volt-
age
3 Looseness, disconnection or
converse of compressor wiring
connection
4 Defective fan of indoor/outdoor
units
5 Short cycle of indoor/outdoor
units
6 Defective input circuit of out-
door controller board
7 Defective compressor
8 Defective outdoor power circuit
board
9 Dip switch setting difference of
outdoor controller circuit board
21
Judgment and action
1 Correct the wiring (U V W phase) to
• •
compressor. Refer to 8-7 (Outdoor power cir-
cuit 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 8-6.
1 Open stop valve.
2 Check facility of power supply.
3 Correct the wiring (U·V·W phase) to
compressor. Refer to 8-7 (Outdoor power cir-
cuit board).
4 Check indoor/outdoor fan.
5 Solve short cycle.
6 Replace outdoor controller circuit board.
W Before the replacement of the outdoor con-
troller circuit board, disconnect the wiring to
compressor from the outdoor power circuit
board and check the output voltage among
phases, U, V, W, during test run.
No defect on board if voltage among phases
(U-V, V-W and W-U) is same. Make sure to
perform the voltage check with same per-
forming frequency.
7 Check compressor. Refer to 8-5.
8 Replace outdoor power circuit board.
9 Check the dip switch setting of outdoor con-
troller circuit board.