Service manual

12-7
TROUBLESHOOTING
SM HADDCI 1-A.2 GB
12.1.5 Simple procedures for checking the Main Parts
12.1.5.1 Checking Mains Voltage.
Confirm that the Mains voltage is between 198 and 264 VAC. If Mains voltage is out of this range,
abnormal operation of the system is expected. If in range check the Power (Circuit) Breaker and
look for broken or loosed cable lugs or wiring mistake(s).
12.1.5.2 Checking Power Input.
If Indoor unit power LED is unlighted, power down the system and check the fuse of the Indoor
unit. If the fuse is OK replace the Indoor unit controller. If the fuse has blown, replace the fuse
and power up again.
Checking Power Input procedure for the Outdoor unit is the same as with the Indoor unit.
12.1.5.3 Checking the Outdoor Fan Motor.
Enter Test Mode (where the OFAN speed is high)
Check the voltage between lead wires according to the normal value as following:
Between red wire and black wire: 310VDC +/- 20V
Between orange wire and black wire: 15VDC +/- 1V
Between yellow wire and black wire: 2-6VDC
12.1.5.4 Checking the Compressor.
The compressor is brushless permanence magnetic DC motor. Three coil resistance is same.
Check the resistance between three poles. The normal value should be below 0.5 ohm
(TBD).
12.1.5.5 Checking the Reverse Valve (RV).
Running in heating mode, check the voltage between two pins of reverse valve connector,
normal voltage is 220VAC.
Checking the electrical expansion valve (EEV).15.1.5.1
The EEV has two parts, drive part and valve. The drive part is a step motor; it is ringed on the
valve. Check the drive voltage (12VDC). When Outdoor unit is power on, EEV shall run and
have click and vibration.
12.1.6 Precaution, Advise and Notice Items
12.1.6.1 High voltage in Outdoor unit controller.
Whole controller, including the wires that are connected to the Outdoor unit controller may have
the potential hazard voltage when power is on. Touching the Outdoor unit controller may cause
an electrical shock.
Advise: Don’t touch the naked lead wire and don’t insert finger, conductor or anything else into
the controller when power is on.
12.1.6.2 Charged Capacitors
Three large-capacity electrolytic capacitors are used in the Outdoor unit controller. Therefore,
charging voltage (380VDC) remains after power down. Discharging takes about four minutes
after power is off. Touching the Outdoor unit controller before discharging may cause an
electrical shock.
12.1.6.3 Additional advises
When disassemble the controller or the front panel, turn off the power supply. 
When connecting or disconnecting the connectors on the PCB, hold the whole housing, don’t 
pull the wire.
There are sharp fringes and sting on shell. Use gloves when disassemble
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