Error Code
Abnormal point and detection method
Judgment and action
Case
27
UF
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 board
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U
•
V
•
W phase) to
compressor.
Refer to 10-7 (Outdoor power circuit board).
4
Check compressor.
Refer to 10-5.
5
Replace outdoor power circuit board.
Ud
Overheat protection
Abnormal if liquid thermistor (TH3), con-
densing temperature T
63HS
detects 70
:
or more during compressor operation.
1
Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
2
Defective liquid thermistor
(TH3), condensing temperature
T
63HS
3
Defective outdoor controller 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.
UE
Abnormal pressure of pressure sensor
(63HS)
Abnormal if pressure sensor (63HS)
detects 0.1 MPa or less.
Detection is inoperative for 3 minutes after
compressor starting and 3 minutes after
and during defrosting.
1
Disconnection or contact
failure of connector (63HS) on
the outdoor controller circuit
board
2
Defective pressure sensor
3
Defective outdoor controller
circuit board
1
Check connection of connector (63HS) on
the outdoor controller circuit board.
Check breaking of the lead wire for
thermistor (63HS).
2
Check pressure by microprocessor.
(Pressure sensor/ 63HS)
(SW2: Refer to 10-8.)
3
Replace outdoor controller board.
UH
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.)
• Abnormal if 40A (SW100/120V) of input
current is detected or 37A (SW100/120V)
or more of input current is detected for 10
seconds continuously.
1
Disconnection of compressor
wiring
2
Defective circuit of current
sensor on outdoor power circuit
board
3
Decrease of power supply
voltage
1
Correct the wiring (U
•
V
•
W phase) to
compressor. Refer to 10-7 (Outdoor power
circuit board).
2
Replace outdoor power circuit board.
3
Check the facility of power supply.
UL
Low pressure (63L operated)
(SW100/120 only)
Abnormal if 63L is operated (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 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
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 10-5.
10
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowings
a) Increase of DC bus voltage
to 420V.
b) Decrease in PFC control
voltage to 12V DC or lower
c) Increase in input current to
50A peak
(SW75VHA only)
1
Abnormal increase in power
source voltage
2
Decrease in power source
voltage, instantaneous stop
3
Disconnection of compressor
wiring
4
Misconnection of reactor (ACL)
5
Defective outdoor power circuit
board
6
Defective reactor (ACL)
7
Disconnection or loose
connection of CN2 on the
outdoor power circuit board/
controller circuit board
PFC/IGBT error (Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310V or
lower for consecutive 10 seconds
(SW·VHA only)
1
Incorrect switch settings on the
outdoor controller circuit board for
model select
2
Defective outdoor power circuit
board
3
Defective outdoor controller circuit
board
1
Correction of a model select
2
Replace outdoor power circuit board.
3
Replace outdoor controller circuit board.
12
Check the field facility for the power
supply.
3
Correct the wiring (U.V.W phase) to
compressor. Refer to 10-7 (Outdoor power
circuit board).
4
Correct the wiring of reactor (ACL).
5
Replace outdoor power circuit board.
6
Replace reactor (ACL).
7
Check CN2 wiring.
20
Detailed
codes
U9
OCH533A
