– 59 –
7. Temporary Switch
0V
Fig. 7-1
37 X1
C701
ZD701
R709
R603
R710
TEMPORARY SWITCH
SW701
0V
12V
0V
MICRO COMPUTER
Micro computer
Fan PMW output
Output divider
R920
Q903
35V
5V
5V
Q904
R904
R905
R921
R915
R910
R909
R906
R902
L901
RED
YEL
BLU
Terminal board D
D901
C901
R901
R903
57
C933
C940
0V
0V
0V
0V
0V
0V
0V
0V
R931
R932
R930
D902
Fig. 8.1
Fan current
detection
I
J
M
8
9
5
4
3
2
1
C942
CN10
Indoor DC
Fan motor
●
The temporary switch is used to operate the air conditoner 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.
Fig. 7-1
8. DC Fan Motor Drive Circuit
●
Fig. 8-1 shows the indoor DC fan motor drive circuit.
Fig. 8-1
●
The circuit produces the fan motor drive voltages, 8-33V, from 35V DC supplied from the outdoor unit and
controls the fan motor speed.
●
Q903 is switched on and off according to the signal at fan PWM output pin
J
to control the voltage which
is smoothed by D901, L901 and C901 to drive the fan motor.
●
The output voltage is divided by R901 and R903 and is input to divided voltage output pin
8
; the micro
computer controls the fan PWM output so the output voltage is set to the specified value. The chopper
frequency of the fan PWM output is 15.7kHz.
●
In the Fan current detection circuit, 35V line current is detected by R906
`
R915 and input to fan current
detection pin
9
. Microcomputer detects overcurrent comparing it with the current judgment value
corresponding to the fan rotation speed.
Содержание RAC-25CNH11
Страница 35: ... 35 CIRCUIT DIAGRAM MODEL RAS 25CNH11 ...
Страница 36: ... 37 CIRCUIT DIAGRAM MODEL RAC 25CNH11 ...
Страница 104: ... 113 PARTS LIST AND DIAGRAM MODEL RAS 25CNH11 11 2 18 8 20 19 12 63 1 4 60 3 7 14 15 6 5 16 13 88 61 17 9 62 10 ...
Страница 106: ... 115 MODEL RAC 25CNH11 55 22 59 16 26 24 23 20 21 19 13 52 58 53 56 57 2 3 51 15 14 18 4 5 9 6 8 54 17 7 11 10 12 25 ...
Страница 108: ...RAS 25CNH11 RAC 25CNH11 PM NO 0164E Printed in Malaysia HITACHI ...