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CDMOS200
DMOS200
VMOS200
CVMOS200
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
The door is opened by pushing the open button on the control
panel, refer to the Figure D-1. When the open button is
pushed, the open button pushes up the switch lever, and then
the switch lever pushes up the latch head. The latch heads
are moved upward and released from latch hook. Now the
door will open.
Figure D-1. Door Open Mechanism
PRIMARY SWITCH, SECONDARY SWITCH &
DOOR SENSING SWITCH
The primary switch and secondary switch mounted parrallel
to each other horizontally in the lower positions of the latch
hook, the door sensing switch is mounted horizontally in the
upper position of the latch hook. They are activated by the
latch head on the door. When the door is opened, the switches
interrupt the power to all high voltage components, except the
oven lamp . A cook cycle cannot take place until the door is
firmly closed thereby activating all interlock switches. The
secondary interlock system consists of the door sensing
switch and the secondary interlock relay located on the
control circuit board.
MONITOR SWITCH
The monitor switch is activated (the contacts opened) by the
latch head on the door while the door is closed. The switch is
intended to render the oven inoperative, by means of blowing
the monitor fuse, when the contacts of the primary switch fail
to open when the door is opened.
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, primary switch and
secondary switch are in the OFF condition (contacts open)
due to their being normally open contact switches.
2. As the door goes to a closed position, the monitor switch
contacts are first opened and then the door sensing switch,
primary switch and secondary switch contacts close. (On
opening the door, each of these switches operate inversely.)
3. If the door is opened, primary switch and contacts fail to
open, the monitor fuse blows simultaneously with closing
of the monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN MONITOR
FUSE, TEST MONITOR SWITCH AND PRI-
MARY SWITCH FOR PROPER OPERATION.
(REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE, AND MONITOR 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 channelled
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.
MONITOR FUSE
1. The monitor fuse blows when the contacts (COM-NO) of
the primary 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.
CAVITY TEMPERATURE FUSE
The cavity temperature fuse 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 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
o
F(150
o
C) causing the oven to shut down.
NOTE: This is fuse. It does not reset.
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 magnetron temperature
fuse will open at 302
o
F(150
o
C) causing the oven to shut down.
NOTE: This is fuse. It does not reset.
Door Sensing
Switch
Monitor Switch
Switch Lever
Secondary
Switch
Latch Heads
Door
Primary
Switch