12-5
TROUBLESHOOTING
SM TRIO52 1-A.2 GB
1.4 judgment by Mega Tool
Mega Tool is a special tool to monitor the system states.
Using Mega Tool requires:
x
A computer with RS232C port.
x
A connection wire for MegaTool.
x
Special MegaTool software.
Use MegaTool according to following procedure:
x
Setup MegaTool software: copy the software to the computer.
x
Connect RS232C port in computer with MegaTool port in Indoor/Outdoor unit controller by the
connection wire.
x
Run the software and choose the COM port, you can monitor the A/C system state in monitor tab
.
1.5 Simple Procedures for Checking the Main Parts
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).
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.
1.5.3 Checking the PCB.
Appearance inspect: Check discoloration, nick and connection of copper foil, short-circuit and open-circuit,
component soldering, bulgy and distortion of electrolytic capacitor.
Power circuit check: check voltage of every power level (5V, 12V, 15V) printed on back of PCB.
1.5.4 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:
x
Between red wire and black wire: /- 20V
x
Between orange wire and black wire: 15VDC +/- 1V
x
Between yellow wire and black wire: 2-6VDC
1.5.5 Checking the Compressor.
The compressor is brushless permanence magnetic DC motor. Three coil resistances are same. Check the
resistance between three poles. The normal value should be 0.642 ohm (U-V), 0.636 ohm (V-W) and 0.652
ohm (U-W). (Environmental temperature 25ºC)
1.5.6 Checking the Reverse Valve (RV).
Running in heating mode, check the voltage between two pins of reverse valve connector, normal voltage is
220VAC
.
1.5.7 Checking the Electrical Expansion Valve (EEV).
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
.
CONTENTS
