7
DCM24B
DCM24R
DCM24S
damper switch contacts. The opening of the damper
switch contacts sends a signal to the LSI on the control
unit de-energizing the relay (RY4) and opening the
circuit to the damper motor.
3. Thecoilofheaterrelay(RY3)isenergizedbythecontrol
unitandthemainsupplyvoltageisappliedtotheheating
element.
4. Whentheoventemperaturereachestheselectedpreheat
temperature, the following operations occur:
4-1 The heater relay is de-energized by the control unit
temperature circuit and thermistor, opening the
circuit to the heating element.
4-2. The oven will continue to function for 30 minutes,
turningtheheateronandoff,asneededtomaintain
the selected preheat temperature. The oven will
shut-down completely after 30 minutes
CONVECTION COOKING CONDITION
Whenthepreheattemperatureisreached,abeepsignalwill
sound indicating that the holding temperature has been
reached in the oven cavity. Open the door and place the
food to be cooked in the oven. Touch the CONVECTION
padfirstandthentouchtheTemperaturepad.Andprogram
desired cooking time by touching the Number pads. When
the START pad is touched, the following operations occur:
1. The numbers on the digital read-out start to count down
to zero.
2. The oven lamp, turntable motor, cooling fan motor and
convection motor are energized.
3. Heaterrelay(RY3)isenergized(ifthecavitytemperature
is lower than the selected temperature) and the main
supplyvoltageisappliedtotheheatingelementtoreturn
to the selected cooking temperature.
4. Uponcompletionofthecookingtime,theaudiblesignalwill
sound,and oven lamp, turntable motor, cooling fan motor
and convection motor are de-energized. At the end of the
convection cycle, if the cavity air temperature is above
275˚F,thecircuittoRY6willbemaintained(bythethermistor
circuit) to continue operation of the cooling fan motor until
thetemperaturedropsbelow245˚F,atwhichtimetherelay
will be de-energized, turning off the fan motor. Relay RY5
will however, open as soon as the convection cycle has
ended, turning off the convection fan motor.
5. At the end of the convection cook cycle, shut-off relay
(RY4) is energized turning on the damper motor. The
damper is returned to the open position, closing the
damper switch contacts which send a signal to the
control unit, de-energizing shut-off relay (RY4).
AUTOMATIC MIX COOKING CONDITION
Touch the HIGH MIX/ROAST or the LOW MIX/BAKE pad
first.Andthenprogramdesiredcookingtimebytouchingthe
Numberpads.TheLOWMIX/BAKEpadispreprogrammed
for 350˚F with 10% microwave power, while the HIGH MIX/
ROAST pad is preprogrammed for 300˚F with 30% micro-
wavepower.WhentheSTARTpadistouched,thefollowing
operations occur:
1. The numbers on the digital read-out start to count down
to zero.
2. The shut-off relays (RY1,RY2,RY3,RY5 and RY6) are
energized, turning on the oven lamp, turntable motor,
cooling fan motor and convection fan motor.
3. The shut-off relay (RY4) is energized.
The damper door is closed from the open position.
4. The heater relay (RY3) is energized, applying the main
supply voltage to the heating element.
5. Now, the oven is in the convection cooking condition.
6. When the oven temperature reaches the selected
temperature, the following operations occur:
6-1. Thepowersupplyvoltageisalternatedtotheheating
element and power transformer.
6-2. The heating element operates through the heater
relay (RY3) contacts and the power transformer
operates through the primary interlock relay (RY2)
contacts.
6-3. These are operated by the control unit to supply
alternatelywithina32secondtimebase,convection
heat and microwave energy.
The relationship between the convection and microwave
power operations are as follows.
Note: The ON and OFF time ratio does not correspond
with the percentage of microwave power, because
approx. 2 seconds are needed for heating of the
magnetron filament.
Note: During alternate Microwave/Convection operation,
the convection heater is energized only if the cavity
temperature drops below the set temperature.
SENSOR COOKING CONDITION
Using the SENSOR COOK, SENSOR REHEAT or POP-
CORNfunction, the foods are cooked without figuringtime,
power level or quantity. When the oven senses enough
steam from the food, it relays the information to its micro-
processor which will calculate the remaining cooking time
and power level needed for best results. When the food is
cooked,watervaporisdeveloped.Thesensor“senses”the
vapor and its resistance increases gradually. When the
resistance reaches the value set according to the menu,
supplementary cooking is started. The time of supplemen-
tary cooking is determined by experiment with each food
category and inputted into the LSI.
An example of how sensor works:
1. Potatoesatroomtemperature.
Vapor is emitted very slowly.
12 SEC. 20 SEC.
32 SEC.
LOW MIX
BAKE
HIGH MIX
ROAST
MICROWAVE POWER
= APPROX. 30%
CONVECTION
TEMPERATURE
=300˚F
MICROWAVE POWER
= APPROX. 10%
CONVECTION
TEMPERATURE
= 350˚F
26 SEC.6 SEC.
ON
ON
OFF
OFF
OFF
ON
(MICRO.)
(CONVEC.)
(MICRO.)
(CONVEC.)
