Samsung MH18ZC1(C2)-09 Service Manual page 34

5-4-5 When the outdoor unit fan does not operate
1) Inspection items
(1) The outdoor unit fan motor operates only when the operating conditions are satisfied and is
selected by the RY74(LOW) and PY75(HI) to rotate.
(2) Is the power voltage normal?
(3) Is the contact of outdoor unit fan motor (CN73) good?
(4) Is the winding resistance of outdoor unit fan motor 58Ω at Hi side and 143Ω at low side?
(5) The outdoor unit fan motor operates with Hi at over 28˚C and low at below 26˚C during the
cooling operation, and operates with Hi at below 14˚C and low at over 15˚C during the
heating operation.
2) Inspection sequence
Apply the power to the outdoor unit and operate the indoor unit.
Is the indoor unit under operating conditions?
Is it operating in the High speed?
Is the voltage shown across the connector (1)↔(3)
((1)↔(5))(the rating voltage ±10% range)?
Is no. 11 ( 12) of IC 06 at low? (DC 0.7 V)
Is pin no. 48(49) of IC 04 (MICOM) at High (DC 5 V)?
Is the outdoor unit fan motor under the operating
conditions?
* Operating specification of the FAN of outdoor unit
(1) When the COMP is under the COMP ON condition during the cooling and heating operation,
Hi or LOW operation is selected according to the temperature condition of outdoor room.
(2) When A room and B room are mixed to operate , it is always under low operation.
(3) Perform the comp ON/OFF control in the dry mode.
(4) When it is under the operation of anti-freezing, overload protection, defrost operation, it may
be Low, high or Off.
(5) Hi = High speed, Low = Low speed
Samsung Electronics
Y
N
N
N
N
N
Normal
N
Normal (operation off)
Y
Y
Check the winding resistance of outdoor unit fan
motor winding resistance → Replace
Y
Contact bad of RY 74(Low), RY 75(High)
Y
Defect of IC06 output
Y
Defect of IC 04(MICOM) - replace the IC 04 or PCB
Troubleshooting
Normal
→ Replace
→ Replace
ass'y
5-11