32
Error Code Meaning of error code and detection method
Judgment and action
UL
(1300)
Abnormal low pressure (63L worked)
Abnormal if 63L is worked (under-
0.03MPa) during compressor operation.
63L: Low-pressure switch
1
Stop valve of outdoor unit is
closed during operation.
2
Disconnection or loose connection
of connector (63L) on outdoor
controller circuit board
3
Disconnection or loose
connection of 63L
4
Defective outdoor controller cir-
cuit board
5
Leakage or shortage of refrigerant
6
Malfunction of linear expansion
valve
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 12-6.
Case
UF
(4100)
Compressor overcurrent interruption
(When compressor locked)
Abnormal if overcurrent of DC bus or
compressor is detected within 30 seconds
after compressor starts operating.
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 circuit
board
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U•V•W phase) to
compressor.
Refer to 12-9.
4
Check compressor.
Refer to 12-6.
5
Replace outdoor power circuit board.
UH
(5300)
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.)
1
Disconnection of compressor
wiring
2
Defective circuit of current
sensor on outdoor power
circuit board
1
Correct the wiring (U•V•W phase) to
compressor. Refer to 12-9.
2
Replace outdoor power circuit board.
UP
(4210)
Compressor overcurrent interruption
Abnormal if overcurrent DC bus or com-
pressor is detected after compressor starts
operating for 30 seconds.
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 circuit board
7
Defective compressor
8
Defective outdoor power circuit
board
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U•V•W phase) to
compressor. Refer to 12-9.
4
Check indoor/outdoor fan.
5
Solve short cycle.
6
Replace outdoor controller circuit board.
7
Check compressor.
Refer to 12-6.
W
Before the replacement of the outdoor
controller 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 performing frequency.
8
Replace outdoor power circuit board.
U9
(4220)
Abnormality such as overvoltage or
voltage shortage and abnormal
synchronous signal to main circuit
Abnormal if any of followings are detected
during compressor operation;
• Instantaneous decrease of DC bus voltage
to 400V
• Increase of DC bus voltage to 760V
• Decrease of input current of outdoor unit
to 0.5A only if operation frequency is more
than or equal to 40Hz or compressor
current is more than or equal to 5A
1
Decrease of power supply voltage
2
Defective 52C drive circuit of
outdoor power circuit board
3
Disconnection or loose
connection of CN5 on the
outdoor power circuit board or
outdoor noise filter circuit board
4
Defective ACCT of outdoor
noise filter circuit board
5
Disconnection or loose
connection of CN2 on the
outdoor power circuit board
1
Check the facility of power supply.
2
Replace outdoor power circuit board.
3
Check CN5 wiring on the outdoor power
circuit board or outdoor noise filter circuit
board.
Refer to 12-9.
4
Replace outdoor noise filter circuit board.
5
Check CN2 wiring on the outdoor power
circuit board.
Refer to 12-9.
OC338C-2.qxp 07.5.24 11:29 AM Page 32
