Samsung AC052MN4DKH Service Manual page 69

Troubleshooting
1. Test items
1) Check the connection of Fan connectors (CN90, CN91)
2) Check the voltage of the fan motor connector in the inverter PBA of the outdoor unit.
3) Check the power connection of the outdoor unit Inverter PCB.
4) Check the Fan Motor single parts. (Be sure to turn off the power and separate the motor connector after 30 seconds!)
2. Check procedure
Make sure to check after power Off!
Check the connection
of the fan connectors (CN90, CN91 or CN901).
1. Is the outdoor fan connector correctly connected?
2. Are the wires of the outdoor fan
connector correctly connected?
Check the
outdoor unit Inverter PCB fan
connector voltage
on, check the voltage between connector pins.
1. Is the DC_Link voltage correct? (Normal: 280Vdc ≤
DC_Link voltage ≤ 360Vdc)
2. Is the fan control voltage correct? (Normal: 14Vdc ≤
FAN control voltage ≤ 16Vdc)
3. Is the fan command voltage?
(Normal: 2Vdc ≤FAN
command voltage
≤ 5Vdc)
Check the
single parts of Fan Motor.
(Be sure to turn off the power and check after
30 seconds!)
1. Are the resistance values between pins of the fan
motor connector similar to those in the
following table?
checking normal operation
At least 30 seconds after power is OFF, attach/detach the fan motor connector!
Check the Inverter PCB or Fan Motor single parts and only if there is a fault, replace!
Do not replace the Main PCB of the outdoor unit relating to the fault in the Fan Motor!
If the error is indicated on 7-segment of the Main PCB of the outdoor unit, the Main PCB of the outdoor unit has no fault.
In case of a control problem, it is possible to solve with S/W update.
4-34
Yes
After power is
Yes
Yes
No
Connect the fan connectors (CN90, CN91 or CN901) correctly.
Power on. After checking normal operation, end the service.
Check the power connection of the Inverter PCB of the outdoor unit.
1. Check by referring to When the outdoor unit power is not ON -
No
Initial Diagnosis.
PCB at the fault in the Inverter PCB.
#1-#3 DC_Link Voltage (between DC_link and GND)
#4-#3 DC_Link voltage (between DC15V and GND)
#5-#3 FAN command voltage
(between fan control and GND)
Measuring Part
No
Motor Connector
Threatened to cause secondary damage to the motor and the PCB.
Check everything is normal after replacing the
End the service.
280Vdc ~ 360Vdc
Diagnosing Part Value of good product
#5(YEL)-#3(BLK) resistance
(between fan control and Open (infinite resistance)
GND)
#4(WHT)-#3(BLK) resistance
Approx. 1.0kΩ ~ 3kΩ
(between DC15V and GND)
#5(YEL)-#3(BLK) resistance
(between fan control and Approx. 230kΩ ~ 280kΩ
GND)
#6(BLU)-#3(BLK) resistance
some MΩ or more or open
(between feedback and
(infinite resistance value)
GND)
Samsung Electronics
14Vdc ~ 16Vdc
2Vdc ~ 5Vdc