Lennox Y6760, Service Manual

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Installation and Maintenance
Service Manual
6. High temperature and overload protection (AP1 below means control board of outdoor unit) E8
Main detection points:
● If the outdoor ambient temperature is in normal range;
● If the indoor and outdoor fan are running normally;
● If the radiating environment of indoor and outdoor unit is good.
Malfunction diagnosis process:
Start
If the outdoor ambient temperature is
higher than 53°C?
If the airflow of indoor and outdoor unit
is good?
If the indoor and outdoor fan are
running normally?
Replace outdoor
mainboard
Connect normally?
Adjust the
connection
Replace fan
capacitor
Replace motor
Fan capacitor is broken?
Motor is broken?
Replace mainboard
Improve the radiating environment of
unit (clean the heat exchanger and
remove surrounding obstacles)
Normal protection, please use it
after improving the outdoor ambient
temperature
Unit restarts
normally
Unit restarts
normally
End
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
No
No
No