12 COMPONENT TEST PROCEDURE
CAUTION
1.High voltage is present at the high voltage terminal of the high voltage transformer during any cook cycle.
2.It is neither necessary nor advisable to attempt measurement of the high voltage.
3.Before touching any oven components, or wiring, always unplug the oven from its power source and discharge the high voltage capacitor.
12.1.Primary Interlock Switch
(SAFETY SWITCH A), Secondary Interlock Switch (SAFETY SWITCH B) and Power Relay
1.Unplug the power cable.
2.Unplug lead wire connectors to Power Relay
3.Unplug lead wire connectors to Primary Interlock Switch and Secondary Interlock Switch.
4.Test the continuity of switches with the door in both open and closed positions with ohm meter (low scale). Normal continuity readings should be as follows.
|
|
|
| Door Opened |
| Door Closed |
Primary | Interelock | Ω | (open) | 0Ω | (close) | |
Switch |
|
|
|
|
|
|
Secondary |
| Interlock | Ω | (open) | 0Ω | (close) |
Switch |
|
|
|
|
|
|
Power Relays |
| Ω | (open) | 0Ω | (close) | |
check continuity.
2.Normal (cold) resistance readings should be as follows:
·Secondary winding Approx. 40Ω — 100Ω
·Filament winding Approx. 0Ω
·Primary winding Approx. 0Ω — 3Ω
12.4. High voltage capacitor
1.Check continuity of capacitor with meter on highest OHM scale.
2.A normal capacitor will show continuity for a short time, and then indicate 9MΩ once the capacitor is charged.
3.A shorted capacitor will show continuous continuity.
4.An open capacitor will show constant 9MΩ .
5.Resistance between each terminal and chassis should be infinite.
12.5. Magnetron
Continuity checks can only indicate an open filament or a shorted magnetron. To diagnose for an openfilament or shorted magnetron.
1.Isolate magnetron from the circuit by disconnecting the leads.
2.A continuity check across magnetron filament terminals should indicate one ohm or less.
3.A continuity check between each filament terminal and magnetron case should read open.
12.2.Short/Monitor Switch (Both Right and Left)
|
| Door Opened |
| Door Closed |
NO Terminals | Ω | (open) | 0Ω | (close) |
NC Terminals | 0Ω | (close) | Ω | (open) |
12.3. High voltage transformer
1. Remove connections from the transformer terminals and
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