Service Manual for
RCO Speed Oven
12
1. Remove the unit from its power source and follow
the proper Lockout/Tagout procedures.
2. Remove the Top Panel.
3. Tag and disconnect the wires to the defective Solid
State Relay.
4. Remove the defective relay.
5. Install the replacement Solid State Relay.
6. Refer to the tags or the schematic and reconnect
all of the wires.
7. Attach all covers and panels.
8. Restore power to the unit and test for proper relay
operation.
MONITOR RELAY
Before performing any service that
involves electrical connection or disconnection
and/or exposure to electrical components, always
follow the Electrical LOCKOUT/TAGOUT Procedure.
Disconnect all circuits. Failure to comply can
cause property damage, injury or death.
The Monitor Relay is located on the electrical panel in
the top front of the unit.
Monitor
Relay
Location of Monitor Relay
Operational Testing
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. The Monitor circuit trips the internal 30A Fast
Blow Fuse with a door open / microwave fault state
through the output contacts of the Monitor Relay. The
Monitor Relay coil is energized by feedback from the
Mag SSR output through the normally closed contacts
of the Monitor Door Switch.
Failure of the Mag SSR, failure of components in the
magnetron system, or a combination of failures of the
controller PCB, the Primary Door Switch, and the Secondary
Door Switch are sources of Monitor circuit activation and
the resultant fuse trip. The Monitor Relay output contacts
experience excessive current loads when activated
preventing future operation of this safety circuit.
The Monitor Relay must be replaced if the 30A fuse
in the oven trips. Do not attempt to reuse a Monitor
Relay after a fuse trip event.
The Primary and Secondary Door Switch interrupt the
function of the microwave and heating circuits when the
oven door is open or ajar. Improper function of either or
both the Primary and Secondary Door Switches will prevent
the oven from heating and prevent microwave functions.
Monitor Relay Replacement
1. Remove the unit from its power source and follow
the proper Lockout/Tagout procedures.
2. Remove the top panel
3. Tag and disconnect the defective relay’s wires.
4. Remove the defective relay.
5. Install the new Monitor Relay.
6. Restore power to the unit and test for proper
operation.
7. Remove power and reattach all covers and panels.
8. Restore Power to the unit.
VOLTAGE RELAY
Before performing any service that
involves electrical connection or disconnection
and/or exposure to electrical components, always
follow the Electrical LOCKOUT/TAGOUT Procedure.
Disconnect all circuits. Failure to comply can
cause property damage, injury or death.
The Voltage Relay is located on the electrical panel in
the top front of the unit.