8
R-410FK
R-410FW
Door Sensing
Switch
Monitor Switch
Switch Lever
Primary Interlock
Switch
Latch Heads
Door
DESCRIPTION AND FUNCTION OF COMPONENTS
DOOR OPEN MECHANISM
Thedoorisopenedbypushingtheopenbuttononthecontrol
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
DOOR SENSING AND PRIMARY INTERLOCK
SWITCHES
Theprimaryinterlockswitchismountedinthelowerposition
ofthelatchhookandthedoorsensingswitchinthesecond-
ary interlock system is mounted in the upper position of the
latchhook.Theyareactivatedbythelatchheadsonthedoor.
Whenthedoorisopened,theswitchesinterruptthepowerto
allhighvoltagecomponents.Acookcyclecannottakeplace
untilthedoorisfirmlyclosedtherebyactivatingbothinterlock
switches. The secondary interlock system consists of the
doorsensingswitchandsecondaryinterlockrelaylocatedon
the control circuit board.
MONITOR SWITCH
Themonitorswitchisactivated(thecontactsopened)bythe
latch head on the door while the door is closed. The switch
is intended to render the oven inoperative, by means of
blowing the C/T fuse, when the contacts of the secondary
interlockrelay(RY2)andprimaryinterlockswitchfailtoopen
whenthedoorisopened.
Functions:
1. Whenthedoorisopened,themonitorswitchcontactclose
(totheONcondition)duetotheirbeingnormallyclosed.At
thistimethe secondary interlock relay (RY2)andprimary
interlock 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
contactsarefirstopenedandthenthedoorsensingswitch
andtheprimaryinterlockswitchcontactsclose.(Onopening
the door, each of these switches operate inversely.)
3. If the door is opened, and the secondary interlock relay
(RY2)andprimary interlock switch contacts failtoopen,
the C/T fuse blows simultaneously with closing of the
monitor switch contacts.
CAUTION: BEFORE REPLACING A BLOWN C/T FUSE
TEST THE DOOR SENSING SWITCH, SEC-
ONDARY INTERLOCK RELAY (RY2), RELAY
(RY1), PRIMARY INTERLOCK SWITCH AND
MONITOR SWITCH FOR PROPER OPERA-
TION.(REFER TO CHAPTER"TEST PROCE-
DURE").
NOTE: C/T FUSE AND MONITOR SWITCH ARE
REPLACED AS AN ASSEMBLY.
TURNTABLE MOTOR
The turntable motor rotates the turntable located on the
bottomofthe oven cavity, so thatthefoodson the turntable
cookevenlyduringcooking.Theturntablemayturnineither
direction.
COOLING FAN MOTOR
Thecoolingfanmotordrivesabladewhichdrawsexternalcool
air.Thiscoolairisdirectedthrough the airvanessurrounding
themagnetronandcoolsthemagnetron.Thisairischanneled
throughtheovencavitytoremovesteamandvaporsgivenoff
from the heating foods. It is then exhausted through the
exhausting air vents at the oven cavity.
CAVITY TEMPERATURE FUSE
The cavity temperature fuse located on the top of the oven
cavity,isdesignedtopreventdamagetotheovenbyfire.Ifthe
foodloadisovercooked,byeithererrorincooktimeordefect
in the control unit, the cavity temperature fuse will open.
Undernormaloperation,thecavitytemperaturefuseremains
closed. However, when abnormally high temperatures are
reachedwithintheovencavity,thecavitytemperaturefusewill
open at 302OF(150OC) causing the oven to shut down.
NOTE: This is fuse. It does not reset.
C/T TEMPERATURE FUSE
TheC/Tfuselocatednearthemagnetronisdesignedtoprevent
damagetothemagnetronifanoverheatedconditiondevelops
inthetubeduetocoolingfanfailure,obstructedairguide,dirty
or blocked air intake, etc.
Under normal operation, the C/T fuse remains closed. How-
ever,whenabnormallyhightemperatures are reachedwithin
themagnetron,theC/Tfusewillopenat302OF(150OC)causing
the oven to shut down.
1. TheC/Tfuseblows whenthecontacts(COM-NO)ofthe
secondary interlock relay (RY2) and primary interlock
switchremainclosedwiththeoven door openandwhen
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.
NOTE: This is fuse. It does not reset.