– 119 –
8. Reversing valve control circuit
Fig. 8-1
Reversing valve control circuit will switch reversing valve ON/OFF according to instruction from indoor
microcomputer depending on the operation condition shows in Table 8-1.
Voltage at Q701 (between Collector and Emitter) in each operation condition is approximately as shown
in Table 8-1 when measured by multimeter.
1
0
7
Q
f
o
e
g
a
t
l
o
v
r
o
t
c
e
ll
o
C
n
o
i
t
i
d
n
o
c
n
o
i
t
a
r
e
p
O
Cooling
General operation of Cooling
In normal heating operation
Defrosting
Sensor dry
MAX. rotation speed instructed
by indoor microcomputer after
defrost is completed
Heating
Dehumidifying
About 0.8V
About 0.8V
About 0.8V
About 35V
About 35V
Table 8-1
V
4
6
6
CN2
POWER P.W.B.
Reversing
valve
DC voltmeter
or tester
2
12V
D701
Q701
D-0V
R706
R705
PQ701
CN4B
CN4A
MAIN P.W.B.
R701
Microcomputer
C-35V
24
