61
U2
U1
U8
Ud
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P4
P5
P6
P8
Indication
Error
Error
code
w
1
Outdoor controller board
Contents
Inspection method
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
2 blinking
3 blinking
W
1 Error code displayed on remote controller
W
2 Refer to service manual for indoor unit.
4 blinking
5 blinking
6 blinking
7 blinking
1 blinking
2 blinking
3 blinking
4 blinking
4 blinking
Abnormality of shell thermostat
and discharging temperature (TH4)
1
Check if stop valves are open.
2
Check if connectors (TH4, LEV-A) on outdoor controller board are not
disconnected.
3
Check if unit fills with specified amount of refrigerant.
4
Measure 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
1
Check if indoor/outdoor units have a short cycle on their air ducts.
2
Check if connector (63H) on outdoor controller board is not disconnected.
3
Check if heat exchanger and filter are not dirty.
4
Measure resistance values among terminals on linear expansion valve using a
tester.
1
Check if stop valves are open.
2
Check looseness, disconnection, and converse connection of compressor wiring.
3
Measure resistance values among terminals on compressor using a tester.
4
Check if outdoor unit has a short cycle on its air duct.
Compressor over current breaking (Start-up locked)
Compressor over current 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
1
Check if indoor/outdoor units have a short cycle on their air ducts.
2
Measure resistance value of outdoor thermistor(TH8).
1
Check the outdoor fan motor.
2
Check if the connector of TH3 on outdoor controller board is disconnected.
Abnormality of voltage
1
Check looseness, disconnection, and converse connection of compressor wiring.
2
Measure resistance value among terminals on compressor using a tester.
3
Check the continuity of contactor (52C).
4
Check if power supply voltage decreases.
5
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
1
Check if connectors (CN20, CN21, CN29 and CN44) on indoor controller board
are not disconnected.
2
Measure resistance value of indoor thermistors.
Abnormality of drain sensor (DS)
Float switch (FS) connector open
Indoor drain overflow protection
1
Check if connector (CN31)(CN4F) on indoor controller board is not disconnected.
2
Measure resistance value of indoor thermistors.
3
Measure resistance value among terminals on drain-up machine using a tester.
4
Check if drain-up machine works.
5
Check drain function.
Freezing (cooling)/overheating
(heating) protection
1
Check if indoor unit has a short cycle on its air duct.
2
Check if heat exchanger and filter is not dirty.
3
Measure resistance value on indoor and outdoor fan motors.
4
Check if the inside of refrigerant piping is not clogged.
Abnormality of pipe
temperature
1
Check if indoor thermistors (TH2 and TH5) are not disconnected from holder.
2
Check if stop valve is open.
3
Check converse connection of extension pipe. (on plural units connection)
4
Check if indoor/outdoor connecting wire is connected correctly. (on plural units
connection)
P.30
P.30
P.32
P.32
P.33
P.32
P.31
P.31
P.31
P.31
P.32
W
2
W
2
W
2
W
2
W
2
W
2
Detailed
reference
page
Protection from overheat operation (TH3)
OCH415A-3.qxp 08.2.21 8:14 AM Page 61
