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R-1850
R-1851
energized, the oven lamp, turntable motor, cooling fan
motor and convection motor are turned on.
2. The coil of relay (RY6) is energized by the control unit.
The damper is moved to the closed position, opening the
damper switch contacts. The opening of the damper
switch contacts sends a signal to the LSI on the control
unit de-energizing the relay (RY6) and opening the
circuit to the damper motor.
3. The coil of heater relay (RY3) is energized by the control
unit and the main supply voltage is applied to the heating
element.
4. When the oven temperature reaches the selected preheat
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,
turning the heater on and off, as needed to maintain
the selected preheat temperature. The oven will
shutdown completely after 30 minutes
CONVECTION COOKING CONDITION
When the preheat temperature is reached, a beep signal will
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.
Program convection temperature and desired cooking time
by touching the CONVECTION pad, Temperature pad and
NUMBER pad.
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. Heater relay (RY3) is energized (if the cavity temperature
is lower than the selected temperature) and the main
supply voltage is applied to the heating element to return
to the selected cooking temperature.
4. Upon completion of the cooking time, the audible signal
will sound, and oven lamp, turntable motor, cooling fan
motor and convection motor are de-energized. At the
end of the convection cycle, if the oven temperature is
above 275˚F, the circuit to RY5 will be maintained (by the
thermistor circuit) to continue operation of the cooling fan
motor until the temperature drops below 245˚F, at which
time the relay will be de-energized, turning off the fan
motor. Relay RY7 will however, open as soon as the
convection cycle has ended, turning off the convection
motor.
5. At the end of the convection cook cycle, shut-off relay
(RY6) 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 (RY6).
AUTOMATIC MIX COOKING CONDITION
Touch the LOW MIX/BAKE or HIGH MIX/ROAST pad. The
LOW MIX/BAKE pad is preprogrammed for 325˚F with 10%
microwave power, while the HIGH MIX/ROAST pad is
preprogrammed for 325˚F with 30% microwave power.
Program desired cooking time. 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 shut-off relays (RY1, RY4, RY5 and RY7) are
energized, turning on the oven lamp, turntable motor,
cooling fan motor and convection motor.
3. The shut-off relay (RY6) is energized.
The damper plate 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. The power supply voltage is alternated to the heating
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
alternately within a 32 second time base, 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.
12 SEC.
20 SEC.
32 SEC.
LOW MIX
BAKE
HIGH MIX
ROAST
MICROWAVE POWER
= APPROX. 30%
CONVECTION
TEMPERATURE
325˚F (165˚C)
MICROWAVE POWER
= APPROX. 10%
CONVECTION
TEMPERATURE
= 325˚F (165˚C)
26 SEC.
6 SEC.
ON
ON
OFF
OFF
OFF
ON
(MICRO.)
(CONVEC.)
(MICRO.)
(CONVEC.)
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-
CORN function, the foods are cooked or defrosted without
figuring time, power level or quantity. When the oven senses
enough steam from the food, it relays the information to its
microprocessor which will calculate the remaining cooking
time and power level needed for best results.
When the food is cooked, water vapor is developed. The
sensor “senses” the vapor and its resistance increases
gradually. When the resistance reaches the value set ac-
cording to the menu, supplementary cooking is started.
The time of supplementary cooking is determined by experi-
ment with each food category and inputted into the LSI.
An example of how sensor works:
