35
Service Manual for
RCO Speed Oven
HIGH VOLTAGE CAPACITOR
MUST BE DISCHARGED BEFORE PERFORMING
THIS PROCEDURE. WAIT AT LEAST FIVE
(5) MINUTES AFTER SHUTDOWN OF HIGH
VOLTAGE SYSTEM.
3. Discharge the high voltage capacitor as described
in the Discharging The High Voltage System section
of this manual.
4. Ensure that the High Voltage Capacitor is fully
discharged before commencing work.
5. Remove HV assembly, including disconnecting the
magnetron terminals.
6. Remove all connections from the High Voltage
diode.
7. Using a megohmmeter, test for continuity between
diode terminals. Reverse megohmmeter leads and
check again. Check for the following results:
a. Short circuit in both directions: replace diode.
b. Open circuit in both directions: replace diode.
c. Conducts one way and shows leakage the
other way: replace diode.
d. Conducts in one direction only: diode is good.
Monitor Relay
Monitor
Relay
Monitor Relay
The monitor relay is a component of the monitor
circuit. The Monitor circuit protects against hazardous
microwave leakage by disabling the oven if a fault
exist in the microwave system with the oven’s door
open or ajar.
Tools Required
• Digital Multimeter
Test Procedure
1. Remove the oven from its power source.
2. Remove the top panel to gain access to the monitor
relay.
3. Disconnect RED 101 from the relay input contact.
4. Disconnect the wires connected to the relay output
contacts [WHT 97 on the COM and YEL 1S on the
NO].
5. Measure resistance across the relay NO and COM
output contacts (should be open). Verifies relay
contacts are open (not welded).
6. If the relay is shorted with no coil voltage present
(it is faulty), replace the relay.
7. If the relay operates as intended, proceed to the
next step.
8. Connect YEL 1S to the open input relay contact.
This will apply coil voltage.
9. With the oven door closed, reconnect the oven to
its power source.
10. Measure resistance across the relay NO and COM
output contacts (should have continuity; i.e. near
short). Verify relay contacts pull in.
11. If the relay is open with coil voltage present (it is
faulty), replace the relay.
12. If relay operates as intended, remove the oven
from its power source.
13. Rewire to the original configuration.
a. Reconnect RED 101 to the relay input contact.
b. Reconnect WHT 97 on the COM.
c. Reconnect YEL 1S on the NO.
14. Reinstall top panel.
OVEN FRONT
Monitor
Switch
Primary
Interlock
Switch
Monitor (top) & Primary (bottom) Interlock
Switches –
Right Side of Oven
