60
OCH721A
Indication
Error
Outdoor controller board
Contents
Check
code*
1
Inspection method
Detailed
reference
page
LED (Green) LED2 (Red)
2 blinking 5 blinking Serial communication error
<Communication between outdoor
controller board and outdoor power board>
<Communication between outdoor
controller board and M-NET P.C. board>
Ed
1
Check if connector (CN4) on outdoor controller board and outdoor
power board is not disconnected.
2
Check if there is poor connection of connector on outdoor
controller board(CNMNT and CNVMNT).
3
Check M-NET communication signal.
P.33
Communication error of M-NET system A0–A8
P.34–P.36
3 blinking 1 blinking Abnormality of shell thermistor
(TH33)
and discharging temperature (TH4) U2
1
Check if stop valves are open.
2
Check if connectors (TH4, TH33, 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.
P.28
2 blinking Abnormal high pressure (High
pressure switch 63H operated.)
U1
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 is not dirty.
4
Measure resistance values among terminals on linear expansion
valve using a tester.
P.28
3 blinking Abnormality of outdoor fan
motor rotational speed
U8
1
Check the outdoor fan motor.
P.29
4 blinking Compressor overcurrent breaking
(Startup locked)
UF
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.
P.31
Compressor overcurrent breaking
UP
P.31
Abnormality of current sensor (P.B.) UH
P.31
Abnormality of power module
U6
P.29
5 blinking Open/short of discharge thermistor (TH4) U3
1
Check if connectors (TH3, TH4, TH6 and TH7) on outdoor controller board
and connector (CN6) on outdoor power board are not disconnected.
2
Measure resistance value of outdoor thermistors
P.29
Open/short of outdoor thermistors
(TH3, TH6, TH7, and TH8)
U4
P.29
6 blinking Abnormality of Heat sink
temperature
U5
1
Check if indoor/outdoor units have a short cycle on their air ducts.
2
Measure resistance value of outdoor Heat sink thermistor(TH8).
P.29
7 blinking Abnormality of voltage
U9
1
Check looseness, disconnection, and converse connection of
compressor wiring.
2
Measure resistance value among terminals on compressor using a tester.
3
Check if power supply voltage decreases.
4
Check the wiring of CN2.
P.30
4 blinking 1 blinking Abnormality of room temperature thermistor (TH1) P1
1
Check if connectors (CN20, CN21, CN29, and CN44) on indoor
controller board are not disconnected.
2
Measure resistance value of indoor thermistors.
*2
Abnormality of pipe temperature
thermistor/Liquid (TH2)
P2
*2
Abnormality of pipe temperature
thermistor/Condenser-Evaporator (TH5) P9
*2
2 blinking Abnormality of drain sensor (DS)
Float switch connector open(FS)
P4
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 pump using a tester.
4
Check if drain pump works.
5
Check drain function.
*2
Indoor drain overflow protection
P5
*2
3 blinking
Freezing (cooling)/overheating
(heating) protection
P6
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.
*2
4 blinking
Abnormality of pipe
temperature
P8
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)
*2
5 blinking Abnormality of indoor controller
board
Fb
1
Replace indoor controller board.
*2
Inndoor fan motor trouble
Pb
1
Check the winding of an indoor unit fan motor.
*2
―
―
Abnormality of remote controller
board
E1
E2
1
Replace remote controller.
P.32
*1
Check code displayed on remote controller
*2
Refer to the indoor unit service manual.