Service Diagnosis
54
L3
Description
ELECTRICAL BOX TEMPERATURE RISE (COMPRESSOR OFF)
Possible Root
cause
1. Fin temperature rise due to defective outdoor unit fan.
2. Fin temperature rise due to short circuit.
3. Fin thermistor defective.
4. Connector in poor contact.
5. Outdoor unit PCB defective.
Troubleshooting
*Remark:
Refer to Appendix A for thermistor resistance check procedures.(Page 67, item 6.1)
Refer to Appendix A for outdoor fan system check. (Page 72, item 6.7)
Refer to Appendix A for installation condition check. (Page 71, item 6.6)
Models
A °C (°F)
Class 09/12
78 (172.4)
class 18/24
122 (251.6)
Error again?
No
Yes
Check heat sink thermistor
resistance.
Change heat sink or check
outdoor fan condition.
Turn off the unit and turn
on back after 20 mins.
Resistance normal?
Heat sink
temperature >
A
°C?
No
Yes
Outdoor fan
functioning?
Yes
Heat sink dirty?
Yes
Check outdoor fan.
No
No
Clean the heat sink.
No
Change
outdoor
fan motor.
Check
installation
condition.
Change
outdoor
PCB.
Change
thermistor.