26
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 board
1
Open stop valve.
2
Check facility of power supply.
3
Correct the wiring (U•V•W phase) to
compressor.
Refer to "9-6.TEST POINT DIAGRAM".
(Outdoor power circuit board).
4
Check compressor.
Refer to "9-4. HOW TO CHECK THE
PARTS".
5
Replace outdoor power circuit board.
Ud
(1504)
Overheat protection
Abnormal if TH3, condensing temperature
T
63HS
detects 70
:
or more during com-
pressor operation.
TH3: Thermistor <Liquid>
1
Defective outdoor fan (fan
motor) or short cycle of outdoor
unit during cooling operation
2
Defective 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 check code. If U4 is displayed, follow
the U4 processing direction.
UE
(1302)
Abnormal pressure of 63HS
Abnormal if 63HS detects 0.1 MPa or less.
Detection is inoperative for 3 minutes after
compressor starting and 3 minutes after
and during defrosting.
63HS: High pressure sensor
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 63HS.
2
Check pressure by microprocessor.
(Pressure sensor/ 63HS)
(SW2: Refer to "9-7. FUNCTION OF
SWITCHES, CONNECTORS AND
JUMPERS".)
3
Replace outdoor controller board.
Abnormal point and detection method
Cause
Judgment and action
10
PFC error (Overvoltage/
Undervoltage/Overcurrent)
• PFC detected any of the fol-
lowing
a) Increase of DC bus voltage
to 420 V.
b) Decrease in PFC control
voltage to 12 V DC or lower
c) Increase in input current to
50A peak
(For models equipped with
single-phase PFC only)
Not applicable for SW75,100V/Y,
SHW80,112V/Y
Check for the switch settings for Model Select
on the outdoor controller circuit board.
20
PFC/IGBT error
(Undervoltage)
• When Compressor is running,
DC bus voltage stays at 310 V or
lower for consecutive 10 seconds
(SW75, 100V, SHW80, 112V 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.
UH
(5300)
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 (SW75, 100V,
SHW80,112V) of input current is detected
or 37A (SW75, 100V, SHW80,112V) 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
4
Leakage or shortage of
refrigerant
1
Correct the wiring (U
•
V
•
W phase) to
compressor. Refer to "9-6.TEST POINT
DIAGRAM" (Outdoor power circuit board).
2
Replace outdoor power circuit board.
3
Check the facility of power supply.
4
Check leakage of refrigerant.
UL
(1300)
Low pressure (63L operated)(SW100/
SHW80/SHW112 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 "9-4. HOW TO CHECK THE
PARTS".
U9
(4220)
Detailed
codes
From the previous page.
Check code
OCH651
