– 104 –
9. Initial Setting Circuit (IC401)
When power is supplied, the microcomputer reads the data in IC401 (E
2
PROM) and sets the preheating
activation value and the rating and maximum speed of the compressor, etc. to their initial values.
Data of self-diagnosis mode is stored in IC401; data will not be erased even when power is turned off.
Fig. 9-1
Microcomputer
External ROM
SCL
SDA
0V
0V
0V
5V
5V
5V
C401
IC401 (E
2
PROM)
R404
R403
27
26
1
2
3
4
8
7
6
5
}
10. Temporary Switch Circuit
The temporary switch is used to operate the air conditioner temporarily when the wireless remote control
is lost or faulty.
The air conditioner operates in the previous mode at the previously set temperature. However, when the
power switch is set to OFF, it starts automatic operation.
TEMPORARY SW
MICROCOMPUTER
R611
Temporary
switch
0V
C611
C642
48
0V
5V
Fig. 10-1