Like the above BLOCK DIAGRAM, LINE of AC 220V is connected to RELAY for COMP and COMMON for
HEATER RELAY, respectively. At this time, if RELAY is not operated, contact point is NC state and R-
Defroster HEATER RELAY is OFF state. So, LOAD maintains OFF state. If COMP becomes the conditions for
operation and COMP RELAY is operated (move to contact point NO), COMP becomes closed-circuit and
operated and makes power for both ends of F, R-Defroster HEATER OFF state. If F-Defroster HEATER comes
to operate, power for both ends of COMP should be OFF.
Purpose of the application of the above circuit : to block all power for both ends of Defroster-HEATER on the
operation of COMP and to block all power for both ends of COMP on F-Defroster HEATER.
<Co-operation Table>
Operation condition
Load condition
Remark
COMP and F, R-Defroster HEATER OFF
COMP, Defroster
RELAY ALL OFF
COMP RELAY operation
F-Defroster HEATER operation
COMP ON and F, R-Defroster
HEATER OFF
Block of power for both ends of
F, R-Defroster HEATER
F-Defroster HEATER ON
COMP OFF
Block of power for both ends of
andCOMP
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