75
U2
U1
U8
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P4
P5
P6
P8
Fb
E1
E2
Indication
Error
Error
code
+
1
Outdoor controller board
Contents
Inspection method
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
2 blinking
3 blinking
1 Error code displayed on remote controller
2 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 thermistor (TH32)
and discharging temperature (TH4)
Check if stop valves are open.
Check if connectors (TH4, TH32, LEV-A) on outdoor controller board are not
disconnected.
Check if unit is filled with specified amount of refrigerant.
Measure resistance values among terminals on indoor valve and outdoor linear
expansion valve using a tester.
Abnormal high pressure (High
pressure switch 63H operated.)
Abnormality of outdoor fan
motor rotational speed
Check if indoor/outdoor units have a short cycle on their air ducts.
Check if connector (63H) on outdoor controller board is not disconnected.
Check if heat exchanger and filter is not dirty.
Measure resistance values among terminals on linear expansion valve using a
tester.
Check if stop valves are open.
Check looseness, disconnection, and converse connection of compressor wiring.
Measure resistance values among terminals on compressor using a tester.
Check 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)
Check if connectors (TH3, TH4, TH6 and TH7) on outdoor controller board and conn-
ector (CN3) on outdoor power board are not disconnected.
Measure resistance value of outdoor thermistors.
Abnormality of heatsink
temperature
Check if indoor/outdoor units have a short cycle on their air ducts.
Measure resistance value of outdoor heatsink thermistor(TH8).
Check the outdoor fan motor.
Abnormality of voltage
Check looseness, disconnection, and converse connection of compressor wiring.
Measure resistance value among terminals on compressor using a tester.
Check the continuity of contactor (52C).
Check if power supply voltage decreases.
Check the wiring of CN52C.
Check 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)
Check if connectors (CN20, CN21, CN29, and CN44) on indoor controller board
are not disconnected.
Measure resistance value of indoor thermistors.
Abnormality of drain sensor (DS)
Float switch connector open(FS)
Indoor drain overflow protection
Check if connector (CN31)(CN4F) on indoor controller board is not disconnected.
Measure resistance value of indoor thermistors.
Measure resistance value among terminals on drain pump using a tester.
Check if drain pump works.
Check drain function.
Freezing (cooling)/overheating
(heating) protection
Check if indoor unit has a short cycle on its air duct.
Check if heat exchanger and filter is not dirty.
Measure resistance value on indoor and outdoor fan motors.
Check 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
Check if indoor thermistors (TH2 and TH5) are not disconnected from holder.
Check if stop valve is open.
Check converse connection of extension pipe. (on plural units connection)
Check if indoor/outdoor connecting wire is connected correctly. (on plural units
connection)
Replace indoor controller board.
Replace remote controller.
P.37
P.37
P.39
P.39
P.40
P.39
P.38
P.38
P.38
P.38
P.39
2
2
2
2
2
2
+
2
P.40
Detailed
reference
page
OCH481C
