Table of Contents
Advertisement
Functions:
1. When the door is opened, the monitor switch
contact close (to the ON condition) due to their
being normally closed. At this time the secondary
interlock relay (RY2), and primary interlock switch
are in the OFF condition (contacts open) due to their
being normally open contact switches. The contacts
of relay (RY1) are in the ON condition (contacts
close).
2. As the door goes to a closed position, the monitor
switch contacts are first opened and then the door
sensing switch and the primary interlock switch
contacts close. (On opening the door, each of these
switches operate inversely.)
3. If the door is opened, and the secondary interlock
relay (RY2) and primary interlock switch contacts fail
to open, the monitor fuse blows simultaneously with
closing of the monitor switch contacts.
CAUTION
Before replacing a blown monitor fuse test the
door sensing switch, secondary interlock relay
(RY2), relay (RY1), primary interlock switch and
monitor switch for proper operation. (Refer to
"Test Procedure").
NOTE
Monitor fuse and switch are replaced as an assembly.
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.
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 magnetron 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.
Section 2 Operation
CAVITY TEMPERATURE FUSE
The cavity temperature fuse located on the top of the
oven cavity, is designed to prevent damage to the oven
by fi re. If the food load is overcooked, by either error
in cook time or defect in the control unit, the cavity
temperature fuse will open.
Under normal operation, the cavity temperature fuse
remains closed. However, when abnormally high
temperatures are reached within the oven cavity, the
cavity temperature fuse will open at 302°F(150°C)
causing the oven to shut down.
NOTE
The cavity temperature fuse does not reset.
MONITOR FUSE
1. The monitor fuse blows when the contacts (COM-
NO) of the primary 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.
MAGNETRON TEMPERATURE FUSE
The magnetron temperature fuse located near the
magnetron is designed to prevent damage to the
magnetron if an over heated condition 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 abnormally high temperatures are reached within
the magnetron, the temperature fuse will open at 257°F
(125°C) causing the oven to shut down. The magnetron
temperature fuse is not reset at room temperature.
2-5
Hide quick links:
Advertisement
Table of Contents
