LG ACHH Series Manual page 87

Error No. Error Type
79 Fan Starting Failure
(791) Error
n Error Diagnosis and Countermeasure Flow Chart
Is fan motor assemble
condition normal?
Yes
Are the resistance
Between each phase and insulation
resistance of motor output
terminal normal?
Is fan motor connection
condition normal?
Is fan PCB assembly normal?
Yes
Recheck power and
installation condition
Measuring fan motor
phase resistance
Error Point
Fan Motor initial starting failure
No
Check ODU fan motor assemble condition and locking
Reassemble or replace if abnormality found
1. Check resistance between each motor output terminal
No 2.85 Ω ± 5 % (@25 ℃)
2. Check insulation resistance between ODU fan motor terminal(U,V,W) and pipe
(over 100 M)
→ Replace fan motor if abnormality found
No
1. Check if color of motor output terminal(U,V,W) connector matched with PCB's
2. Check wire disconnection and wiring
→ Reassemble or replace if abnormality found
No
Check fan PCB assembly IPM normal
→ Replace Fan PCB assembly
Measuring insulation resistance
between fan terminal & chassis
Check the connetion condition
1.Fan motor defect/ assemble condition abnor-
mal
2.Fan motor connector misconnection
(Hall sensor, U,V,W ouput)
3.Fan PCB defect
- 87 -
Error code check
Main Reasons
Check
Point