Hitachi RAC-70YH7 Service Manual page 55

8. Temporary Switch
The temporary switch is used to operate the air conditioner temporarily when the wireless remote control
G
is lost or faulty.
The air conditioner operates in the previous mode at the previously set temperature. However, when the
G
power switch is set to OFF, it starts automatic operation.
9. Indoor Fan Motor Feedback Circuit
<Exp. of circuit wave>
G
Fan motor will receive signal thru Joint Connector with VDC (Motor Drive Voltage), VCC (Motor Controller
G
Power Supply), VSC (RPM Instruction) motor WCC return the FG sinal under frequency RPM.
The circuit produces fan
G
motor speed.
CAUTION 1
Indoor fan motor circuit will be connected with primary
power source line and please take care of the
electrical shock.
5V
Temporary
switch
R609
I O
20V
IC201
G
ZD201
0V
5V
R234
Q204
motor drive from 340V DC supplied from the indoor unit and controls the fan
– 65 –
TEMPORARY SW
48
MICRO COMPUTER
0V
Fig. 8-1
340V
5V
15V
PC201
R501
Q502
PC202
Q503
R233
0V
0V
0V
Fig. 9-1
Fig. 9-2
CAUTION 2
Please do not disconnect the fan motor connector during
running due to the high voltage supply, it will cause the
damage at fan motor and PWB.
JOINT
CONNECTOR
VDC
1
0V GND
3
VCC FM
4
VS
5
FG
6
JOINT
CONNECTOR