26
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Disconnect the oven from the power supply.
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You can test continuity of safety interlocks and monitor switch by using switch tester or ohmmeter.
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The switch operation is checked by the lamp on/off of resistance zero/unlimited.
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The sequence of check is interlock monitor switch; primary and secondary interlock switches check.
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Make circuits like Fig. a, Fig. b, Fig. c for tests.
SAFETY INTERLOCK CONTINUITY TEST
1) In case of interlock monitor check.
(Lamp on or zero resistance)
(ohmmeter)
– Fig. a –
Condition: 1) Door is opened.
2) Common terminal of the monitor
switch disconnected.
3) In case of secondary interlock switch.
(Lamp on or zero resistance)
(ohmmeter)
– Fig. c –
Condition : 1) Door is closed.
2) In case of primary interlock check.
(Lamp on or zero resistance)
(ohmmeter)
– Fig. b –
Condition: 1) Door is closed.
ƒN
(Schematic diagram of S/W tester)
POWER
SUPPLY
CORD
POWER
SUPPLY
CORD
PRIMARY
INTERLOCK S/W
PRIMARY
INTERLOCK S/W
NO
NO
COM
COM
NC
NC
INTERLOCK
MONITOR
S/W
INTERLOCK
MONITOR
S/W
SECONDARY
INTERLOCK
S/W
SECONDARY
INTERLOCK
S/W
POWER
SUPPLY
CORD
PRIMARY
INTERLOCK S/W
NO
COM
NC
INTERLOCK
MONITOR
S/W
SECONDARY
INTERLOCK
S/W
CONTACT
LEAD
LAMP
S/W
BATTERY
