Sharp R-8320E, Service Manual

Page: 35 / 140

AUTOMATIC MIX COOKING CONDITION
Program desired cooking time and temperature by touch-
ing the number pads and the “LOW MIX/BAKE” or “HIGH
MIX/ROAST” pad.
When the “COOK” pad is touched, the following opera-
tions occur:
1. The COOK and MIX indicators light, and Convection
Fan Symbol will rotate. The numbers of the digital
readout start the count down to zero.
2. The shut-off relay (RY4) is energized.
The damper door closes from the open position.
3. The shut-off relays RY2 and RY3) are energized,
energizing the oven lamps, turntable motor, cooling fan
motor and convection motor.
4. The heater relay is energized.
The 240 volts is supplied to the heating element.
5. Now, the oven is in the convection cooking condition.
LOW MIX
BAKE
6. When the oven temperature reaches the selected
temperature, the following operations occur:
6-l. The 240 volts A.C. is supplied to the heating
element and power transformer alternately.
6-2. The heating element operates through the
heater relay contacts and the power transformer
operates through the cook relay contacts.
6-3. These are operated by the control unit within
a 32 second time base.
The relationship between the convection and microwave
power operations are as follows.
Note: The ON/OFF time ratio does not correspond
with the percentage of microwave power, be-
cause approx. 2 seconds are needed for heat-
ing of the magnetron filament.
, 6 sec.
l - - y -
26 sec.
&
I
I
I
MICROWAVE POWER
=Approx. 10%
I
I
CONVECTION TEMPERATURE
12
20 sec.
I
I
HIGH MIX
ROAST
I
3 2 s e c .
MICROWAVE POWER
=Approx. 30%
CONVECTION TEMPERATURE
Note : During alternate Microwave/Convection opera-
tion, the convection heater is energized only if
the cavity temperature drops below the set
temperature.
34