Component Test Procedures - ACP OC24 Service Manual

COMPONENT TESTING PROCEDURES
To avoid risk of electrical shock, personal injury or death; disconnect power to oven and discharge capacitor
before servicing, unless testing requires power.
Illustration Component
Magnetron TCO
Latch TCO
Cavity TCO
Diode
Triac
Capacitor
Magnetron
Solenoid (Left, Right)
Stirrer motor
!
WARNING
Testing
Disconnect all wires from TCO.
Measure resistance across terminals.
Magnetron TCO.....................................
Disconnect all wires from TCO.
Measure resistance across terminals.
Latch TCO .............................................
Disconnect all wires from TCO.
Measure resistance across terminals.
Cavity TCO............................................
Discharge Capacitor
Remove diode lead from capacitor and
connect ohmmeter.
Reverse leads for second test.
Resistance Check
Disconnect wires to triac
Measure resistance from:
MT1 to MT2
MT1 to Gate
MT2 to Gate
All terminals to ground
Voltage Check
Measure voltage from:
MT1 to Gate
MT1 to MT2
Discharge Capacitor
Remove wires from capacitor terminals
and connect ohmmeter, set on highest
resistance scale to terminals.
Also check between each terminal and
capacitor case.
Discharge Capacitor
Remove wires from magnetron and
connect ohmmeter to terminals. Also
check between each terminal and
ground.
Disconnect connector from solenoid
Measure resistance across coil................. Approximately 6-11
Remove all wires from motor.
Measure resistance across terminals ....
13
Results
Closed at 257ºF (125ºC) and
Opens at 300ºF (149ºC)
Opens at 230ºF (110ºC) and
Closes at 150ºF (66ºC)
Opens at 219ºF (104ºC)
Infinite resistance should be
measured in one direction and 50K
or less in the opposite direction.
NOTE: Ohmmeter must contain a
battery of 6 volts minimum.
Caution – Do not operate oven with
wire to terminal MT2 removed.
Infinite
Approximately 60Ω
Infinite
Infinite
0.8 VAC when energized.
0 volts when gate energized or closed.
Line volts when gate not energized or
open.
Between Terminals: Meter should
momentarily deflect towards zero then
return to over 5 M. If no deflection
occurs, or if continuous deflection
occurs, replace capacitor.
Terminal to Case: Infinite resistance
Between Terminals: Less than 1
Each terminal to ground measures
Infinite resistance.
Note: This test is not conclusive. If
oven does not heat and all other
components test good replace the
magnetron and retest.
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
Approximately 12K
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