Electrolux Icon E30SO75ESS - Fire Sensing Feature (Microwave Mode)

Operation
2-6
LV TTransformer
C
2
C1
C4
C3
T6
T7
T4
A
3
T2
AA11
D9
R
Y2
RY1
RY5
RY4 RY3
RY6
1
.
0
µ
F
AC 2
3
0
0
V
N
.O.
N.
O.
JM
D
M
F
M
FM
OL
TTM
COM .
B
3
B4
B
1
B
2
B5
B
6
D7
D5
D3
E3
E
5
E
1
D1
2
4
0V 60
H
z
ORG
BRN
RED
BLK
O
RG
RED
R
ED
RE
D
N.O.
COM.
T1
T3
1. Circuits/ Wire colors subject to change without notice.
Notes:
BLK
BLK
BLK
BLK
BLK
BLK
BLK
GRN
GND
WHT
WHT
WHT
GRY
GRY
GRY
WHT
Fuse
20A
Red Red
Red
Red
BRN
BRN
BRN
Side Heater
Thermal
Cut-out
MG
Temp. Fuse
Top Heater
Thermal
Cut-out
Com. Primary
Interlock Relay
Solid-State Relay
Solid-State Relay
Fuse
F10A
Control Unit
Fuse 12.5A
GRN
GRN
GRN
BRN
GRN
WHT
BLK
BLK
RED
BLU
RED
RED
BLU
BLU
ORG
ORGORG
ORG
ORG
Secondary
Interlock Switch
BLK
BLK
BLK
RED
RED
RED
Fan Motor
Oven Lamp
Damper Motor
Jet Motor
GRY GRY
GRY
GRY
GRY
WHT
WHT
WHT WHT
WHT
WHT
BLU
Damper
Switch
Door
Sensing
Switch
Thermistor
RED
RED
BLK
ORG
Magnetron
Power
Transformer With 150˚C Thermostat
In Primary Winding
Capacitor
Rectifier
Side Heater Top Heater
Monitor Switch
Turn Table Motor
BLK
BLKGRY
GRY
WHT
GRY GRY
GRY
ORG
SCHEMATIC
NOTE: CONDITION OF OVEN
1. DOOR CLOSED.
2. ROAST PAD TOUCHED.
3. COOKING TIME PROGRAMMED.
4. “START” PAD TOUCHED.
NOTE: The solid-state relays and relay RY2 are energized alternately.
For last 15 minutes, the contacts of relay RY6 will contact D5.
Figure 2-5. Oven Schematic-Speed Roast Cooking Condition
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
measuring voltage across the temperature measurement
circuit (thermistor) during it’s 32-seconds time base and
comparing 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.
Operation
Please refer to the timing diagrams.
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 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 repeat-
ed (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. The LSI also stops
counting down and closes the damper door so that
no fresh air will enter the oven cavity.
4. Once the fire sensor feature has shut the unit down,
the programmed cooking cycle may be resumed by
pressing the START pad or the unit may be reset by
pressing the CLEAR pad.
CONVECTION
MOTOR
THERMISTOR
Sensing
Voltage
ON
OFF
ON
OFF
ON
OFF
0 2 3 28 31 32 (sec.) 64 (sec.)
3 sec.
Sensing the voltage across temperature measurement circuit.
3 sec.