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16.5.3 Water Pump Abnormality (H20)
Malfunction Decision Conditions:
During startup and operation of cooling and heating, the rotation speed detected by the IPM of water pump motor
during water pump operation is used to determine abnormal water pump (feedback of rotation > 6,000rpm or <
1,000rpm).
Malfunction Caused:
1 Operation stop due to short circuit inside the water pump motor winding.
2 Operation stop due to breaking of wire inside the water pump motor.
3 Operation stop due to breaking of water pump lead wires.
4 Operation stop due to water pump motor IPM malfunction.
5 Operation error due to faulty indoor unit PCB.
Abnormality Judgment:
Continue for 5 seconds.
Troubleshooting:
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Turn ON the power and
operate the water pump.
Does it operate?
No
Check the feedback
signal from water pump
to indoor unit PCB.
Is the water pump control
power supply 15Vdc
(pin5 & 4) generated?
Stop the water pump.
Operate the water pump,
is feedback signal (pulse)
generated between
pin7 & 4 of CN-PUMP1?
Replace the
Replace the
indoor unit PCB.
Replace the
indoor unit PCB.
water pump.
Replace the
water pump.
No
Yes
Yes
Turn OFF the power.
Check if the water
pump connector
connection normal?
Is the water pump drive
power supply voltage
range between
280~373Vdc
(pin1 & 4) generated?
Operate the water pump,
is the duty command
range between 0~6Vdc
(pin6 & 4) generated?
Disconnect the water pump
connector CN-PUMP1.
Turn ON the power and
check the input voltage of
the water pump from
indoor unit PCB.
Yes
No
Replace the
indoor unit PCB.
No
Replace the
indoor unit PCB.
No
Yes
Yes
Yes
No
poor contact
connection
- Connector
- Correct the
Caution