40
Error Code Meaning of error code and detection method
Case
Judgment and action
U7
(1520)
Abnormality of super heat due to low
discharge temperature
Abnormal if discharge super heat is
continuously detected less than or equal
to 0
:
for 3 minutes even though linear
expansion valve has minimum open pulse
after compressor starts operating for 10
minutes.
1
Disconnection or loose
connection of discharge
temperature thermistor. (TH4)
2
Defective holder of discharge
temperature thermistor.
3
Disconnection or loose connection
of linear expansion valve’s coil.
4
Disconnection or loose
connection of linear expansion
valve’s connector.
5
Defective linear expansion valve.
12
Check the installation conditions of
discharge temperature thermistor (TH4).
3
Check the coil of linear expansion valve.
Refer to 10-7.
4
Check the connection or contact of LEV-A and
LEV-B on outdoor controller circuit board.
5
Check linear expansion valve.
Refer to 10-6.
U8
(4400)
Abnormality in the outdoor fan motor
The outdoor fan motor is considered to be
abnormal if the rotational frequency of fan
motor is abnormal when detected during
operation.
Fan motor rotational frequency is abnor-
mal if;
• 100 rpm or below detected continuously
for 15 seconds at 20
:
or more outside
air temperature
• 50 rpm or below or 1500 rpm or more
detected continuously for 1 minute.
1
Failure in the operation of
the DC fan motor
2
Failure in the outdoor circuit
controller board
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 remedy
1
above.)
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;
• Decrease of DC bus voltage to 310V
(RP35-140VHA only)
• Instantaneous decrease of DC bus voltage
RP35-140VHA : 200V,
RP100-140YHA : 350V
• Increase of DC bus voltage to
RP35-71VHA : 420V
RP100-140VHA : 400V
RP100-140YHA : 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
Disconnection of compressor
wiring
3
Defective 52C
4
Disconnection or loose connec-
tion of CN52C (RP35-71VHA
only)
5
Defective PFC module of outdoor
power board (RP35-71VHA only)
6
Defective ACT module (RP100-
140VHA only)
7
Defective ACT module drive
circuit of outdoor power circuit
board (RP100-140VHA only)
8
Disconnection or loose connec-
tion of CNAF (RP100-140VHA
only)
9
Defective outdoor converter
circuit board (RP100-140YHA
only)
0
Defective 52C drive circuit of
outdoor controller circuit board
(RP35-140VHA)
1
Disconnection or loose
connection of CN5 on the
outdoor power circuit board.
2
Defective 52C drive circuit of
outdoor power circuit board.
(RP100-140YHA only)
3
Disconnection or loose
connection of CN2 on the
outdoor power circuit board.
1
Check the facility of power supply.
2
Correct the wiring (U•V•W phase) to compressor.
Refer to 10-9 (Outdoor power circuit board).
3
Replace 52C.
4
Check CN52C wiring.
5
Replace outdoor power circuit board.
(RP35-71VHA only)
6
Replace ACT module. (RP100-140VHA only)
7
Replace outdoor power circuit board.
(RP100-140VHA only)
8
Check CNAF wiring. (RP100-140VHA only)
9
Replace outdoor converter circuit board.
(RP100-140YHA only)
0
Replace outdoor controller circuit board.
(RP35-140VHA only)
1
Check CN5 wiring on the outdoor power
circuit board.
Refer to 10-9.
2
Replace outdoor power circuit board.
(RP100-140YHA only)
3
Check CN2 wiring on the outdoor power
circuit board.
Refer to 10-9.
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 10-9 (Outdoor power circuit board).
4
Check compressor.
Refer to 10-6.
5
Replace outdoor power circuit board.
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