Panasonic WH-ADC0309H3E Service Manual page 152

17.5.3 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:
Turn ON the power and
operate the water pump.
Does it operate?
Yes
Stop the water pump.
Check the feedback
signal from water pump
to indoor unit PCB.
Operate the water pump,
is feedback signal (pulse)
generated between
pin7 & 4 of CN-PUMP1?
Yes
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
No
No
Replace the
water pump.
Replace the
indoor unit PCB.
Turn OFF the power.
Check if the water
pump connector
connection normal?
Yes
Disconnect the water pump
connector CN-PUMP1.
Turn ON the power and
check the input voltage of
the water pump from
indoor unit PCB.
Is the water pump drive
power supply voltage
range between
280~373Vdc
(pin1 & 4) generated?
Yes
Is the water pump control
power supply 15Vdc
(pin5 & 4) generated?
Yes
Operate the water pump,
is the duty command
range between 0~6Vdc
(pin6 & 4) generated?
Yes
152
- Connector
No
poor contact.
- Correct the
connection.
No
Replace the
indoor unit PCB.
No
Replace the
indoor unit PCB.
No
Replace the
indoor unit PCB.
Replace the
water pump.