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109
18.4.15 H37 (Outdoor Liquid Pipe Temperature Sensor Abnormality)
Malfunction Decision Conditions
During startup and operation of cooling and heating, the temperatures detected by the outdoor liquid pipe
temperature sensor are used to determine sensor errors.
Malfunction Caused
Faulty
connector
connection.
Faulty
sensor.
Faulty
PCB.
Troubleshooting
110
18.4.16 H97 (Outdoor Fan Motor – DC Motor Mechanism Locked)
Malfunction Decision Conditions
The rotation speed detected by the Hall IC during fan motor operation is used to determine abnormal fan motor.
Malfunction Caused
Malfunction Caused
Operation stops due to short circuit inside the fan motor winding.
Operation stops due to breaking of wire inside the fan motor.
Operation stops due to breaking of fan motor lead wires.
Operation stops due to Hall IC malfunction.
Operation error due to faulty outdoor unit PCB.
Troubleshooting
FAN MOTOR
CN-MTR2
(WHT)
10
1
W
MS
3
U
5
V
14
16
16
IC19
CN-MTR1
1
2
R105
1k
3
4
5
5V
R111
R120
1k
1k
+
C173
C175
0.01μ
0.01μ
50V
G5
G5
G5
C177
C176
0.01μ
0.01μ
50V
50V
G5
PCB BOARD
Replace fan motor.
Replace outdoor PCB.
Replace fan motor.
Replace fan motor.
Replace outdoor PCB.
Does it rotate?
Is the resistance normal?
Use an inverter check to check on
the power transistor on board.
Connect it to PCB’s CN-MRT2 port.
Turn power ON and run the unit.
the power transistor on board.
Connect it to PCB’s CN-MRT2 port.
Turn power ON and run the unit.
Do all 6 LED light turn ON and turn
OFF periodically?
OFF periodically?
Does the voltage at each terminal
becomes 5 and 0Vdc repeatedly?
becomes 5 and 0Vdc repeatedly?
U
NO
YES
V
W
NO
YES
NO
YES
NO
YES
When abnormality indication starts again
Turn off power supply and rotate fan by
hand.
hand.
Caution
For safety reason and to prevent
component breakdown, always switch
off the power before remove and
connect the component.
component breakdown, always switch
off the power before remove and
connect the component.
Does fan rotate smoothly?
NO
Replace fan motor.
YES
Turn power supply on and operate fan.
Turn off power supply and
disconnect fan motor CN-MRT2
connector.
disconnect fan motor CN-MRT2
connector.
Check resistance of the motor.
Measure at fan motor connector
CN-MRT1 (1-2, 1-3, 2-3).
Measure at fan motor connector
CN-MRT1 (1-2, 1-3, 2-3).
Stop the fan motor
Check the rotation feedback output from
fan motor’s CN-MTR1 output.
Rotate the fan motor manually (by hand)
while measure the voltage at PCB’s
CN-MRT1
- Between 1(+) and 5(-)
- Between 1(+) and 5(-)
- Between 2(+) and 5(-)
- Between 3(+) and 5(-)
111
18.4.17 H98 (Error Code Stored in Memory and no alarm is triggered / no TIMER LED
flashing)
Malfunction Decision Conditions
Indoor high pressure is detected when indoor heat exchanger is detecting very high temperature when the unit is
operating in heating operation.
Phenomena: unit is stopping and re-starting very often in heating mode
Malfunction Caused
Malfunction Caused
Indoor heat exchanger thermistor
Clogged air filter or heat exchanger
Over-bent pipe (liquid side)
Troubleshooting
Troubleshooting
112
18.4.18 H99 (Indoor Freeze Prevention Protection: Cooling or Soft Dry)
Error Code will not display (no Timer LED blinking) but store in EEPROM
Malfunction Decision Conditions
Malfunction Decision Conditions
Freeze prevention control takes place (when indoor pipe temperature is lower than 2°C)
Malfunction Caused
Malfunction Caused
Air short circuit at indoor unit
Clogged indoor unit air filter
Dust accumulation on the indoor unit heat exchanger
2/3 way valve closed
Faulty indoor unit fan motor
Refrigerant
shortage
(refrigerant leakage)
Clogged expansion valve or strainer
Faulty indoor pipe temperature sensor
Faulty indoor unit PCB
Troubleshooting
Troubleshooting
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