Thermal Cut-Out Test; Secondary Interlock Switch Test; Stop Switch Test - Wolf MWD24-2 Service Manual

Drawer Microwave
PROCEDURE LETTER
H
I
J
(Models MWD24-2 / MWD30-2)

THERMAL CUT-OUT TEST:

1. Disconnect the power supply cord.
2. Open the drawer and keep it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. A continuity check across the thermal cut-out terminals should indicate a
closed circuit unless the temperature of the thermal cut-out reaches approxi-
mately 293°F(145°C). An open thermal cut-out indicates overheating of the
oven, exchange the oven thermal cut-out and check inside of oven cavity and
for improper setting of cooking time or operation of control unit. Check for
restricted air flow through the vent holes of the oven cavity, especially the
cooling fan and air guide.
5. Reconnect all leads removed from components during testing.
6. Reassemble the unit.
7. Reconnect the power supply cord.
8. Run the unit and check all functions.
If the thermal cut-out indicates an open circuit at room temperature, replace
thermal cut-out.

SECONDARY INTERLOCK SWITCH TEST:

1. Disconnect the power supply cord.
2. Open the drawer and keep it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and nor-
mally open (NO) terminal of the switch. The meter should indicate an open
circuit with the drawer open and a closed circuit with the drawer closed. If
improper operation is indicated, replace the secondary interlock switch.
5. Reconnect all leads removed from components during testing.
6. Reassemble the unit.
7. Reconnect the power supply cord.
8. Run the oven and check all functions.

STOP SWITCH TEST:

1. Disconnect the power supply cord.
2. Open the drawer and keep it open.
3. To discharge high voltage capacitor, wait for 60 seconds.
4. Isolate the switch and connect the ohmmeter to the common (COM.) and nor-
mally open (NO) terminal of the switch. The meter should indicate an open
circuit with the drawer open and a closed circuit with the drawer closed. If
improper operation is indicated, replace the stop switch.
5. Reconnect all leads removed from components during testing.
6. Reassemble the unit.
7. Reconnect the power supply cord.
8. Run the oven and check all functions.
NOTE: If the stop switch contacts fail in the open position and the door is closed,
the cooling fan motor, stirrer motor and oven light will be activated by RY1.
5-13
COMPONENT TEST
#813632 - Revision B - December, 2009
Troubleshooting Guide