U2
U7
U1
UL
U8
Ud
UF
UP
UH
U6
U3
U4
U5
U9
Indication
Error
Check
code*
Outdoor controller board
Contents
Inspection method
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
2 blinking
3 blinking
*
Check code displayed on remote controller
** Refer to service manual for indoor unit.
4 blinking
5 blinking
6 blinking
7 blinking
1 blinking
4 blinking
4 blinking
Abnormality of discharging
temperature (TH4) and Comp.
surface temperature (TH33)
Abnormality of superheat due
to low discharge temperature
1
Check if stop valves are open.
2
Check if connectors (TH4, 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.)
Abnormal low pressure (Low
pressure switch 63L operated.)
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)(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(Start-up locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
Open/short of outdoor
thermistors (TH4, TH33)
Open/short of outdoor thermistors
(TH3, TH32, TH6, TH7 and TH8)
1
Check if connectors (TH3, TH32, TH4, TH33 and TH7/6) 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 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 connector (TH3) (63HS) 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 if power supply voltage decreases.
4
Check the wiring of CN52C.
5
Check the wiring of CNAF.
Abnormality of room temperature
thermistor (TH1)
Abnormality of pipe temperature
thermistor /Liquid (TH2)
Abnormality of tank temperature
thermistor
1
Check if connectors on indoor controller board are not disconnected.
2
Measure resistance value of indoor thermistors.
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.23
P.24
P.23
P.26
P.24
P.26
P.26
P.27
P.26
P.24
P.23
P.24
P.24
P.25–
P.26
Detailed
reference
page
Protection from overheat
operation (TH3)
P.29
P8
P9
P2
P1
**
**
**
OCH651
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