66
U2
U7
U1
UL
U8
Ud
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P4
P5
P6
P8
Indication
Error
Check
code
*1
Outdoor controller board
Contents
Inspection method
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
2 blinking
3 blinking
*1 Check 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
4 blinking
Abnormality of comp. surface
thermistor(TH34) and discharging
temperature (TH4)
Abnormality of superheat due
to low discharge temperature
1
Check if stop valves are open.
2
Check if connectors (TH4, TH34, LEV-A, and LEV-B) on outdoor controller
board are not disconnected.
3
Check if unit is filled 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 operated.)
Abnormality of outdoor fan
motor rotational speed
1
Check if outdoor units have a short cycle on their air ducts.
2
Check if connector (63H/63L) on outdoor controller board is not disconnected.
3
Check if heat exchanger and filter is 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.
5
Check leakage of refrigerant.
Compressor overcurrent
breaking(Startup locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
Open/short of discharge thermistor (TH4)
and comp. surface thermistor (TH34)
Open/short of outdoor thermistors
(TH3, TH6, TH7 and TH8)
1
Check if connectors (TH3, TH4, TH6, TH7 and TH34) on outdoor controller
board, and connector (CN3) on outdoor power board are not disconnected.
2
Measure resistance value of outdoor thermistors.
Abnormality of heat sink
temperature
1
Check if 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 connector (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 CN52C.
6
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) and terminal
blocks on indoor controller board are not disconnected.
2
Measure resistance value of indoor thermistors.
Note: Refer to the indoor unit's Installation Manual.
Abnormality of drain sensor (DS)
Float switch(FS) connector open
Indoor drain overflow protection
1
Check if connector (CN31)(CN4F) and terminal blocks 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 pump 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.31
P.30
P.33
P.31
P.33
P.33
P.34
P.33
P.34
P.30
P.31
P.31
P.32,33
*2
*2
*2
*2
*2
*2
Detailed
reference
page
Protection from overheat operation(TH3)
Abnormal low pressure (Low
pressure switch 63L operated.)
Note: Refer to the indoor unit's Installation Manual.
OCH533D