DC voltmeter
or multimeter
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 Emittor) in each operation condition is approximately as shown
in Table 8-1 when measured by multimeter.
Table 8-1
Power P.W.B.
MAIN P.W.B.
Reversingvalve
valve
CN2
C-35V
12V
R701
PQ701
D701
Q701
R705
R706
2
4
D-0V
6
6
24
CN4A
CN4B
Micro
computer
V
Operation condition
Cooling
Heating
Dehumidifying
General operation of cooling
In normal heating operation
Defrosting
Sensor dry
About 0.8V
About 35V
About 35V
About 0.8V
About 0.8V
Collector voltage of Q701
MAX. rotation speed instructed by indoor
microcomputer after defrost is completed
- 64 -