Samsung ACH1800E Technical Manual page 160

Fault Diagnosis by Symptom
G EC12 : When the trouble is found on the part related to the fan motor of outdoor unit.
Check point :
- Outdoor unit PCB relay defect
- Output of outdoor unit micom
- Outdoor unit fan motor defect
- Defect of IC07 of outdoor unit PCB
Is the power source normal? AC220~240 50Hz
Is the wire harness for motor connection good?
Is the terminal contact of fan motor condenser good?
YES
Does the outdoor fan motor changes to
mild and strong wind during the cooling
operation?
NO
Do the RY73, RY74 operate?
NO
Is the wind volume output pin of micom high
when each wind control is operation?
YES
Is the voltage across the PCB relay 12V
when the each wind control of micom
is operating?
YES
Are the pins 11 and 12 of IC07 of outdoor
unit PCB low when each wind control mode
micom is operation?
YES
Is the voltage across the outdoor unit
fan motor AC220~240V?
YES
Check outdoor unit fan motor and replace
TROUBLE SHOOTING & ERROR MODE
(Cont.)
NO
YES
YES
NO
NO
NO
NO
Check and replace
the related part
Normal
Check and replace
the micom
Check and replace
the relay
Check and replace
IC07
Replace PCB
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