Description And Function Of Components - Viking DMOR206SS Service Manual

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 open lever, and then the open 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
LATCH
HEADS
DOOR
OPEN LEVER
SECONDARY SWITCH, THIRD DOOR SWITCH &
DOOR SENSING SWITCH
The secondary switch and third switch mounted parrallel to
each other horizontally in the upper 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 un-
til the door is firmly closed thereby activating all interlock
switches. The secondary interlock system consists of the
door sensing switch and the primary 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
and secondary 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
LATCH HOOK
DOOR SENSING
SWITCH
MONITOR FUSE
MONITOR
SWITCH
THIRD
DOOR
SWITCH
SECONDARY
INTERLOCK
SWITCH
operate inversely.)
3. If the door is opened, and the secondary interlock relay,
primary switch and secondary 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 SECONDARY INTERLOCK
RELAY, SECONDARY SWITCH, DOOR SENS-
ING SWITCH, MONITOR SWITCH AND PRI-
MARY SWITCH FOR PROPER OPERATION.
(REFER TO CHAPTER "TEST PROCEDURE").
NOTE: MONITOR FUSE, PRIMARY SWITCH AND
MONITOR SWITCH ARE REPLACED AS AN
ASSEMBLY.
TEMPERATURE FUSE (MG)
The temperature fuse located near the waveguide
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 temperature fuse remains
closed. However, the temperature fuse will open at 302
ο
(150 C) causing the oven to shut down.
THERMAL CUT-OUT (HOOD )
This thermal cut-out located on the base plate right. It
is designed to automatically turn on the hood fan motor
whenever the hot air rising from the conventional range
below causes the temperature at the thermal cut-out to rise
ο ο
to 140 F (60 C) or higher, thus removing this hot air from
around microwave oven. When the temperature around the
thermal cut-out drops to 113
cut-out shuts off the food fan motor.
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottom of the oven cavity, so that the foods on the turnta-
ble cook evenly during cooking. Turntable will turn in either
direction. The turntable motor can be turned off by touching
TURNTABLE ON/OFF pad.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws external
cool air. This cool air is directed through the air vanes sur-
rounding 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.
HOOD FAN MOTOR
The hood fan motor is a two-speed, single-phase, double pole
induction type, requiring a hood fan capacitor. It is located
outside the upper rear part of the oven cavity, is to remove,
from around the oven, hot air rising from the conventional
electric or gas range over which it is installed. This air is then
expelled either vertically or horizontally through the customer
supplied duct system, or discharged back into the kitchen.
17
DMOR206SS
ο ο
F (45 C) or lower, the thermal
is
ο
F