9
R-90GCH
(COM-NO) of relay RY6 are opened.
2. The damper is moved to the closed position.
3. The solid-state relays (SSR1+SSR2) and relay RY2
are energized, and the main supply voltage is applied
to the top and side heating elements and the high
voltage transformer alternately.
NOTE: After cooking, the operation of the fan motors,
damper motor is the same as one of the
convection cooking.
FIRE SENSING FEATURE (MICROWAVE MODE)
This model incorporates a sensing feature which will stop
the oven's operation if there is a fire in the oven cavity
during microwave cooking. This fire sensing feature will
operate when the microwave power level is set to 80% or
more. This is accomplished by the LSI repeatedly meas-
uring the voltage across the temperature measurement
circuit (thermistor) during it's 32-seconds time base com-
paring the obtained voltage measurements. If the most
recent voltage measured is 300 mV greater than the
previous voltage measured, the LSI judges it as a fire in the
oven cavity and switches off the relays to the power
transformer, fan motor and convection motor. The LSI also
stops counting down and closes the damper door so that
no fresh air will enter the oven cavity. Please refer to the
following section for a more detailed description.
AUTOMATIC COOKING
Automatic cooking will automatically compute the oven
temperature, microwave power and cooking time. And the
oven will cook according to the special cooking sequence.
POWER CONTROL FOR MANUAL COOKING
Following table shows the power control for manual cook-
ing.
Operation
Please refer to the timing diagrams below.
1. The fire sensing will start after 30 minutes when the
oven is started.
2. The thermistor operates within a 32-seconds time base
and it is energized for three (3) seconds and off for 29
seconds. Two (2) seconds after the thermistor is
energized, the voltage across the temperature
measurement circuit is sampled by the LSI and twenty
five (25) seconds after the thermistor is cut off the LSI
turns on the convection fan for three (3) seconds.
3. The above procedure is repeated. If the difference
between the first voltage measured (in step 1) and the
voltage measured when the procedure is repeated
(step 2) is greater than 300 mV the LSI makes the
judgment that there is a fire in the oven cavity and will
switch off the relays to the power transformer, fan
motor and convection motor.
Micro ON
Side heaer
%
-
-
70
50
30
10
70
50
30
10
70
50
30
10
70
50
30
10
0
0
0
0
-
-
-
-
-
-
-
-
-
-
-
220˚C
220˚C
190˚C - 200˚C
220 - 250˚C
180˚C
40 - 160˚C
190˚C - 200˚C
220 - 250˚C
180˚C
40 - 160˚C
Cool oven
(Oven Temperature
less than 59˚C)
After preheating
(Oven Temperature
more than 100˚C)
Warm oven
(Oven Temperature
60˚C - 99˚C)
Side heaer
%
-
100
30
50
70
90
30
50
70
90
0
50
70
90
0
50
70
90
20
20
20
20
100
60
60
70
40
50
60
30
40
50
Top heaer
%
-
100
30
50
70
90
30
50
70
70
0
0
70
70
0
0
70
70
20
20
20
20
100
50
50
60
40
40
50
30
30
40
70%
-
50%
50%
30%
10%
50%
50%
30%
10%
50%
50%
30%
10%
50%
50%
30%
10%
-
-
-
-
-
-
-
-
-
-
Micro
%
10, 30, 50
70, 100
-
70
50
30
10
70
50
30
10
70
50
30
10
70
50
30
10
70
50
30
10
-
-
-
-
-
-
-
-
-
-
Micro. OFF
Oven
temperature
Powr down
time
Power after powr down time
Manual
MENU
MICROWAVE
GRILL
REHAET
CONV.
DUAL1
DUAL2
Air
Balancel
Jet
Jet
Conv.
Conv.
Conv.
Conv.
Conv.
Conv.
Conv.
Conv. or Jet
-
0%
-
-
-
50%
0%
0%
0%
-
-
40 - 250˚C
40 - 200˚C
220 - 230˚C
250˚C
40 - 200˚C
220 - 230˚C
250˚C
40 - 200˚C
220 - 230˚C
250˚C
40 min.
30 min.
All
20 min.
All
20 min.
35 min.
20 min.
45 min.
30 min.
No
20 min.
30 min.
30 min.
20 min.
30 min.
30 min.
No
30 min.
30 min.
-
-
-
-
-
-
-
-
-
-
50%
30%
30%
30%
-
-
20%
30%
30%
30%
30%
30%
-
30%
30%
-
0%
0%
20%
20%
20%
-
-
20%
30%
30%
30%
30%
30%
-
30%
30%
Top heaer Side heaer
Side heaer
Micro.
Micro. ON
Micro. OFF
