Interlock Continuity Test - LG LMC1575BD Service Manual

INTERLOCK CONTINUITY TEST

WARNING : FOR CONTINUED PROTECTION AGAINST EXCESSIVE RADIATION EMISSION, REPLACE ONLY WITH
IDENTICAL REPLACEMENT PARTS.
TYPE NO.SZM-V 16-FA-63 FOR PRIMARY SWITCH / TYPE NO.SZM-V 16-FA-61 FOR MONITOR SWITCH / TYPE NO.SZM-V 16-FA-63 FOR SECONDARY SWITCH
A. PRIMARY INTERLOCK SWITCH TEST
When the door is pulled slowly with the door closed, an audible click
should be heard at the same time or successively at intervals. When the
door is closed slowly, the latches should activate the switches with an
audible click. If the latches do not activate the switches when the door is
closed, the switches should be a adjusted in accordance with the
adjustment procedure. Disconnect the wire lead from the primary switch.
Connect the ohmmeter leads to the common (COM) and normally open
(NO) terminal of the switch. The meter should indicate an open circuit in
the door open condition.
When the door is closed, the meter should indicate a closed circuit.
When the primary switch operation is abnormal, make the necessary
adjustment or replace the switch only with the same type of switch.
B. SECONDARY INTERLOCK SWITCH TEST
Disconnect the wire lead from the secondary switch.
COMPONENTS
SWITCHES Check for continuity of the switch with an Ohm-meter
(Wire leads removed)
Primary
Switch
Monitor
Switch
Secondary
Switch
NOTE : After checking for the continuity of switches, make sure that they are connected correctly.
C. MONITOR SWITCH TEST
TEST PROCEDURE
NO NO
COM COM
NO
COM NO
COM
NC
NC
NO
NC NO
COM
COM
NC
NO
COM
NO
COM
NC
NC
NC NO
NO
COM
COM NO NC
COM
NO
COM
NO
NO
COM
NO
COM
COM
NO
COM
5-9
Connect the ohmmeter leads to the common (COM) and normally open
(NO) terminals of the switch. The meter should indicate a open circuit in
the door open condition. When the door is closed, meter should indicate
an closed circuit. When the secondary switch operation is abnormal, make
the necessary adjustment or replace the switch only with the same type of
switch.
Disconnect the wire lead from the monitor switch. Connect the ohmmeter
leads to the common (COM) and normally closed (NC) terminals of the
switch. The meter should indicate closed circuit in the door open condition.
When the door is closed, meter should indicate an open circuit. When the
monitor switch operation is abnormal, replace with the same type of
switch. Check Common and normally open terminals,too. Opposite result
of Common-normally close test is normal.
NOTE: After repairing the door or the interlock system, it is
necessary to do this continuity test before operating the oven.
Door open
RESULTS
Door closed