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U2
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E1
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Indication Error
Error
code
w1
Outdoor controller board
Contents Inspection method
LED1 (Green)
LED2 (Red)
3 blinking 1 blinking
2 blinking
3 blinking
W1 Error code displayed on remote controller
W2 Refer to service manual for indoor unit.
4 blinking
5 blinking
6 blinking
7 blinking
1 blinking
2 blinking
3 blinking
4 blinking
5 blinking
––
4 blinking
Abnormality of shell thermostat
and discharging temperature (TH4)
1Check if stop valves are open.
2Check if connectors (TH4, LEV-A) on outdoor controller board are not
disconnected.
3Check if unit is filled with specified amount of refrigerant.
4Measure resistance values among terminals on indoor valve and outdoor linear
expansion valve using a tester.
Abnormal high pressure (High
pressure switch 63H worked.)
Abnormality of outdoor fan
motor rotational speed
1Check if indoor/outdoor units have a short cycle on their air ducts.
2Check if connector (63H) on outdoor controller board is not disconnected.
3Check if heat exchanger and filter is not dirty.
4Measure resistance values among terminals on linear expansion valve using a
tester.
1Check if stop valves are open.
2Check looseness, disconnection, and converse connection of compressor wiring.
3Measure resistance values among terminals on compressor using a tester.
4Check if outdoor unit has a short cycle on its air duct.
Compressor overcurrent breaking (Start-up locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
Open/short of discharge thermistor (TH4)
Open/short of outdoor thermistors
(TH3, TH6, TH7 and TH8)
1
Check if connectors (TH3, TH4, TH6 and TH7) on outdoor controller board and conn-
ector (CN3) on outdoor power board are not disconnected.
2
Measure resistance value of outdoor thermistors.
Abnormality of heatsink
temperature
1Check if indoor/outdoor units have a short cycle on their air ducts.
2Measure resistance value of outdoor thermistor(TH8).
1Check the outdoor fan motor.
Abnormality of voltage 1Check looseness, disconnection, and converse connection of compressor wiring.
2Measure resistance value among terminals on compressor using a tester.
3Check the continuity of contactor (52C).
4Check if power supply voltage decreases.
5Check the wiring of CN52C.
6Check the wiring of CNAF.
Abnormality of room temperature thermistor (TH1)
Abnormality of pipe temperature thermistor /Liquid (TH2)
Abnormality of pipe temperature
thermistor/Condenser-Evaporator(TH5)
1Check if connectors (CN20, CN21, CN29, and CN44) on indoor controller board
are not disconnected.
2Measure resistance value of indoor thermistors.
Abnormality of drain sensor (DS)
Float switch connector open(FS)
Indoor drain overflow protection
1Check if connector (CN31)(CN4F) on indoor controller board is not disconnected.
2Measure resistance value of indoor thermistors.
3Measure resistance value among terminals on drain-up machine using a tester.
4Check if drain-up machine works.
5Check drain function.
Freezing (cooling)/overheating
(heating) protection
1Check if indoor unit has a short cycle on its air duct.
2Check if heat exchanger and filter is not dirty.
3Measure resistance value on indoor and outdoor fan motors.
4Check if the inside of refrigerant piping is not clogged.
Abnormality of pipe
temperature
Abnormality of indoor con-
troller board
Abnormality of remote con-
troller board
1Check if indoor thermistors (TH2 and TH5) are not disconnected from holder.
2Check if stop valve is open.
3Check converse connection of extension pipe. (on plural units connection)
4Check if indoor/outdoor connecting wire is connected correctly. (on plural units
connection)
1Replace indoor controller board.
1Replace remote controller.
P.37
P.37
P.39
P.39
P.40
P.39
P.38
P.38
P.38
P.38
P.39
W2
W2
W2
W2
W2
W2
w2
P.40
Detailed
reference
page
OCH429--3.qxp 07.11.20 9:19 AM Page 75