Panasonic WH-ADC0916G9E8 WH-UX09FE8 Service Manual page 117

17.5.9 Indoor Backup Heater OLP Abnormality (H70)
Malfunction Decision Conditions:
During operation of indoor backup heater, when no power supplies to indoor backup heater or OLP open circuit.
Malfunction Caused:
1 Faulty power supply connector connection.
2 Faulty connector connection.
3 Faulty indoor backup heater overload protector (OLP).
4 Faulty indoor unit PCB (main).
Abnormality Judgment:
Continue for 60 seconds.
Troubleshooting:
Is the abnormality happened during
operation of indoor backup heater?
Check the indoor backup heater incoming
AC power supply (2):
- Turn ON power supply (2) & RCCB.
- Measure the AC voltage between RCCB's
L1 & N1.
- Measure the AC voltage between PCB's
AC2-L3 & AC2-N2.
Is measured voltage 230Vac?
Check the CN-OLP1 connector connection:
- Turn OFF the power.
- Check the connector connection.
Is the CN-OLP1 connector
connection normal?
No
- Defect in indoor unit PCB (main).
- Replace the indoor unit PCB (main).
Yes
- Defect in RCCB.
- Replace RCCB.
- Terminal board assembly
No
connector poor contact.
- Correct the connection or
replace the indoor unit
Yes
PCB (main).
No
- Connector poor contact.
- Correct the connection.
Yes
For safety reason and to prevent component breakdown,
always switch off the power before remove and connect the component.
Check indoor backup heater OLP
continuity:
- Turn OFF power supply.
- Reset heater 1 OLP.
- Measure the continuity of OLP.
Is there any continuity?
117
Use a test pen to push
this button to reset OLP
Multimeter to
measure continuity
- Defect in indoor backup
No
heater OLP.
- Replace indoor backup
heater OLP.
- Defect in indoor unit
Yes
PCB (main).
- Replace the indoor unit
PCB (main).