R420LW
6 – 4
4. TURNTABLE MOTOR
The turntable motor rotates the turntable located on the bottom of the
oven cavity, so that the foods on the turntable cook evenly during
cooking. The turntable may turn in either direction.
5. COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external cool air.
This cool air is directed through the air vanes surrounding the magne-
tron and cools the magnetron. This air is channeled through the oven
cavity to remove steam and vapors given off from the heating foods. It
is then exhausted through the exhausting air vents at the oven cavity.
6. OVEN THERMAL CUT-OUT
The thermal cut-out, located on the top of the oven cavity, is designed
to prevent damage to the oven by fire. If the food load is overcooked,
by either error in cook time or defect in the control unit, the thermal cut-
out will open. Under normal operation, the oven thermal cut-out
remains closed. However, when abnormally high temperatures are
reached within the oven cavity, the oven thermal cut-out will open at
293
°
F(145
°
C), causing the oven to shut down.
7. MAGNETRON TEMPERATURE FUSE
The magnetron temperature fuse located near the magnetron is
designed to prevent damage to the magnetron if an over heated condi-
tion develops in the tube due to cooling fan failure, obstructed air
guide, dirty or blocked air intake, etc. Under normal operation, the
magnetron temperature fuse remains closed. However, when abnor-
mally high temperatures are reached within the magnetron, the mag-
netron temperature fuse will open at 302
°
F(150
°
C) causing the oven
to shut down.
NOTE: This is a fuse. It does not reset.
8. MONITOR FUSE
1) The monitor fuse blows when the contacts (COM-NO) of the pri-
mary interlock relay (RY2) and secondary interlock switch remain
closed with the oven door open and when the monitor switch
closes.
2) If the wire harness or electrical components are short-circuited, this
monitor fuse blows to prevent an electric shock or fire hazard.
9. NOISE FILER
The noise filter prevents the radio frequency interference that might
flow back in the power circuit.
