25
Service Manual for
RCO Speed Oven
HV Assembly Removed
6. Remove the High Voltage (HV) assembly.
7. Tag and disconnect the HV Transformer wiring.
8. Note the orientation of the transformer before
removing it.
Transformer
Mounting Nuts
HV Transformers on HV Assembly
9. Remove the suspect transformer.
10. Using an Ohmmeter test the transformer windings:
Primary = 208V Tap 0.89 ± 5% Ω and 230V Tap
1.01 ± 5% Ω; Secondary = 65.00 ± 5% Ω.
11. Install the replacement transformer, ensuring it is
oriented correctly.
12. Referring to the tags, reconnect transformer wiring.
13. Reinstall the HV assembly.
14. Referring to the tags, reconnect the Magnetron
and Magnetron Thermal Switch wiring.
15. Reinstall the Magnetron Blower Assembly.
16. Briefly restore the unit to its power source and
verify it is working properly.
Always make sure a load
is in the oven cavity before activating the
microwave circuit.
17. Remove the unit from its power source and reattach
all panels and covers.
18. Restore power to the unit.
HIGH VOLTAGE (HV) CAPACITORS
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 High Voltage Capacitor
retains a 2.5kV DC charge after the oven
has been disconnected from its power source.
The capacitor must be properly discharged
prior to beginning work on any components
in the high voltage area. Failure to comply
can cause property damage, injury or death.
The High Voltage (HV) Capacitors are located at the
rear of the unit behind the Magnetron Blower Assembly.
High Voltage
Capacitors
HV Capacitor Location
Operational Testing
The right and left Mag circuits use identical components
and wiring. Each Mag circuit has a dedicated 2.4KV
secondary supply from the Mag transformer and a high
voltage doubling circuit (capacitor and diode package)
to step up to the 4KV microwave power.
