Hitachi RAM-40QH5 Service Manual page 46

5. Reversing valve control circuit
By reversing valve control circuit you can switch reversing valve ON/OFF (Heating ON) according to
G
instruction from indoor microcomputer and depending on operation condition.
Voltage at each point in each operation condition is approximately as shown below when measured by
tester. (When collector voltage of Q831 is measured)
Cooling
Heating
Dehumidifying
Fig. 5-1
Table 5-1
Operation condition
General operation of Cooling
In normal heating operation
MAX. rotation speed instructed
by indoor microcomputer after
defrost is completed
Defrosting
Sensor dry
Collector voltage of Q831
About 35V
About 0.8V
About 0.8V
About 35V
About 35V
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