– 79 –
5. Reversing valve control circuit
●
Reversing valve control circuit can switch reversing valve ON/OFF according to instruction from indoor
microcomputer depending on the operation condition shows in Table 5-1.
Voltage at each point in each operation condition is approximately as shown below when measured by
tester. (When collector voltage of Q701 is measured)
3
1
16
24
I/F 0V
0V
Fig. 5 – 1
D702
CN2
Q701
DC voltmeter
or tester
Reversing
valve
R701
R703
R219
Q705
FUSE RESISTOR
MICR
OCOMPUTER
PQ701
1
2
3
4
5V
HIC
I/F 35V
R702
V
Operation condition
Collector voltage of Q701
Cooling
Heating
Dehumidifying
General operation of Cooling
In normal heating operation
MAX. rotation speed instructed
by indoor microcomputer after
defrost is completed
Defrosting
Sensor dry
About 35V
About 0.8V
About 0.8V
About 35V
About 35V
Table 5-1
Содержание RAC25NH4
Страница 37: ...CIRCUIT DIAGRAM MODEL RAK 25NH4 RAK 35NH4 RAK 50NH4 37 ...
Страница 38: ...CIRCUIT DIAGRAM MODEL RAC 25NH4 RAC 35NH4 RAC 50NH4 39 ...
Страница 40: ... 42 MODEL RAC 25NH4 RAC 35NH4 RAC 50NH4 MAIN P W B Marking on P W B COMPONENT SIDE ...
Страница 90: ... 100 SELF DIAGNOSIS LIGHTING MODE MODEL RAC 25NH4 RAC 35NH4 RAC 50NH4 ...
Страница 115: ...HITACHI PM NO 0174E Printed in Malaysia RAK 25NH4 RAC 25NH4 RAK 35NH4 RAC 35NH4 RAK 50NH4 RAC 50NH4 ...