R-7280
R-1720
DESCRIPTION AND FUNCTION OF COMPONENTS
,
UPPER LATCH SWITCH
The switch is activated by the upper latch head on the
door while the door is closed.
When the door is opened, the switch interrupts the
circuit (except oven lamp).
LOWER LATCH SWITCH
The switch is activated by the lower latch head on the
door. When the door is opened, the switch interrupts
the circuit to transformer.
A cook cycle cannot take
place until the door is firmly closed and the INSTANT
COOK/START pad touched.
STOP SWITCH
The stop switch is located on latch hook and activated
by the lower latch head and switch lever. When the
open button is depressed while the oven is in cook
cycle, the stop switch contacts open to de-energize the
relay( RY-1 ) and relay( RY-2) circuits in the control and
causes cook time count down to pause.
MONITOR SWITCH
The monitor switch is activated (the contacts of “NC”
opened) by the upper latch head on the door while the
door is closed. The switch is intended to render the
oven inoperative by means of blowning the monitor
fuse when the contacts of the upper latch switch fail
to open when the door is opened.
Functions:
1. When the door is opened, the monitor switch
normal close contacts (to the ON condition) due
to their being normally closed. At this time the
upper latch switch is in the OFF condition (con-
tacts open) due to their being normally open con-
tact switch.
2. As the door goes to a closed position, the monitor
switch normal close contacts are first opened and
then the upper latch switch contacts close and
lower latch switch contacts, (On opening the door,
each of these switches operate inversely.)
3. If the door is opened, and the upper latch switch
contacts fail to open, the monitor fuse blows si-
multaneously with closing of the monitor switch
contacts.
CAUTION:BEFORE REPLACING A BLOWN MONI-
TOR FUSE, TEST THE UPPER LATCH FOR
PROPER OPERATION. (REFER TO CHAP-
TER “TEST PROCEDURE”).
DOOR OPEN MECHANISM
The door can be opened by pushing the open button
on the control panel, refer to the Figure D-l.
When the open button is pushed, the cook switch lever
on the latch hook is moved upward, operating the latch
head. The latch head is moved upward, and released
from the latch hook. Now, the door can be opened.
OVEN LAMP
The oven lamp illuminates the interior of the oven so
that food being cooked can be examined visually
through the door window without having to open the
door.
COOLING FAN MOTOR
The cooling fan motor drives a blade which draws
cooling air through the back vents.
This cooling air is directed through the air vanes sur-
rounding the magnetron and cools the magnetron.
This air is channeled through the oven cavity to remove
steam and vaports given off from the heating foods.
It is then exhausted at the back of the oven cavity.
MAGNETRON TEMP. FUSE
The temp. fuse located on the oven cavity is designed
to prevent damage to the magnetron if an overheated
condition develops in the tube due to cooling fan fail-
ure, obstructed air ducts, dirty or blocked air intake, etc.
Under normal operation, the temp. fuse remains closed.
However, when abnormally high temperatures are
reached within the magnetron, the fuse will open,
causing the oven to shut down.
This is a fuse and it does not reset.
OVEN TEMP. FUSE
When foods in oven cavity fire, oven temperature fuse
stops ventilating from fan motor and extinguishes fire
in oven cavity before fire goes outside the unit,
MONITOR
SWITCH
UPPER
LATCH
SWITCH
LOWER
LATCH
SWITCH
BUTTON
Figure D-1. Latch Switches Adjustment
To Next Page
Loading...
