8
PCOR30B
PCOR30R
PCOR30S
OPERATION
DESCRIPTION OF OPERATING SEQUENCE
Thefollowingisadescriptionofcomponentfunctionsduring
oven operation.
OFF CONDITION
Closing the door activates the door sensing switch and
secondary interlock switch. (In this condition, the monitor
switch contacts are opened.)
When oven is plugged in, 120 volts A.C. is supplied to the
control unit. (Figure O-1).
1. The display will show "Welcome".
Tosetany program or settheclock,youmust first touch
the STOP/CLEAR pad. The display will clear, and " : "
will appear.
COOKINGCONDITION
ProgramdesiredcookingtimetouchingtheNUMBERpads.
When the START pad is touched, the following operations
occur:
1. The contacts of relays are closed and components
connected to the relays are turned on as follows.
(For details, refer to Figure O-2)
RELAY CONNECTED COMPONENTS
RY1 Oven lamp
RY2 Power transformer/ Stirrer motor
RY4 Turntable motor
RY5 Fan motor
2. 120 volts A.C. is supplied to the primary winding of the
power transformer and is converted to about 3.3 volts
A.C. output on the filament winding, and approximately
2000 volts A.C. on the high voltage winding.
3. Thefilamentwindingvoltageheatsthemagnetronfilament
andtheH.V.winding voltageissenttoavoltagedoubler
circuit.
4. The microwave energy produced by the magnetron is
channelled through the waveguide into the cavity feed-
box, and then into the cavity where the food is placed to
be cooked.
5. Upon completion of the cooking time, the power
transformer, oven lamp, etc. are turned off, and the
generation of microwave energy is stopped. The oven
will revert to the OFF condition.
6. When the door is opened during a cook cycle, monitor
switch, door sensing switch, secondary switch and third
doorswitchandprimaryinterlockrelayareactivatedwith
thefollowing results.Thecircuitstothestirrermotor, the
cooling fan motor, the turntable motor, and the high
voltage components are de-energized, and the digital
read-outdisplaysthetimestillremaininginthecookcycle
whenthedoorwasopened.
7. Themonitorswitchiselectricallymonitoringtheoperation
ofthesecondaryandthirddoor door switch and primary
interlock relay and is mechanically associated with the
door so that it will function in the following sequence.
(1) When the door opens from a closed position, the
primary interlock relay, door sensing switch,
secondaryandthirddoorswitchopentheircontacts,
and then the monitor switch contacts close.
(2) When the door is closed from the open position, the
monitor switch contacts first open, and then the
contactsofthesecondaryandthirddoorswitchclose.
Iftheprimaryswitch,secondaryswitchandsecondaryinter-
lock relay fail with their contacts closed when the door is
opened, the closing of the monitor switch contacts will form
a short circuit through the monitor fuse, secondary switch
,third door switch and primary interlock relay, causing the
monitor fuse to blow.
POWER LEVEL P-0 TO P-90 COOKING
WhenVariableCookingPowerisprogrammed,the120volts
A.C. is supplied to the power transformer intermittently
throughthecontactsofrelay(RY2)whichisoperatedbythe
controlunitwithinanintervalsecondtimebase.Microwave
poweroperationisasfollows:
VARI-MODE ON TIME OFF TIME
Power10(P-HI) 32 sec. 0 sec.
(100%power)
Power9(P-90) 30 sec. 2 sec.
(approx.90%power)
Power8(P-80) 26 sec. 6 sec.
(approx.80%power)
Power7(P-70) 24 sec. 8 sec.
(approx.70%power)
Power6(P-60) 22 sec. 10 sec.
(approx.60%power)
Power5(P-50) 18 sec. 14 sec.
(approx.50%power)
Power4(P-40) 16 sec. 16 sec.
(approx.40%power)
Power3(P-30) 12 sec. 20 sec.
(approx.30%power)
Power2(P-20) 8 sec. 24 sec.
(approx.20%power)
Power1(P-10) 6 sec. 26 sec.
(approx.10%power)
Power0(P-0) 0 sec. 32 sec.
(0%power)
Note: TheON/OFFtimeratiodoesnotcorrespondwiththe
percentage of microwave power, because approx.
2secondsare neededforheating ofthemagnetron
filament.
CONVECTIONCOOKINGCONDITION
PREHEATING CONDITION
Program desired convection temperature by touching the
PREHEAT pad and the temperature pad.
When the START pad is touched, the following operations
occur:
