Service Manual

Check SiUS041638E
93 Service Diagnosis
5.2 Indoor Fan Motor Connector Output Check
Check No.02 1. Check the connection of connector.
2. Check the motor power supply voltage output (pins 4 - 7).
3. Check the motor control voltage (pins 4 - 3).
4. Check the rotation command voltage (pins 4 - 2).
5. Check the rotation pulse (pins 4 - 1).
5.3 Power Supply Waveforms Check
Check No.11 Measure the power supply waveform between No. 1 and No. 2 on the terminal board, and check
the waveform disturbance.

Check if the power supply waveform is a sine wave (Fig.1).

Check if there is waveform disturbance near the zero-cross (sections circled in Fig.2).
7
6
5
4
3
2
1
S1
(R19654)
Motor power supply voltage (310 ~ 340 VDC)
Unused
Unused
GND
Motor control voltage (15 VDC)
Rotation command voltage (1~ 6.5 VDC)
Rotation pulse input
Fig.1 Fig.2