Steam Control - Rational SelfCookingCenter SCC Training Manual

Steam Control

Steam supply is controlled in two different ways.
1. At temperatures up to boiling point steam is controlled by the thermocouple B1 in the cabinet
2. At temperatures above boiling point we measure the differential pressure applied to P1 to control the
steam generator.
30°C(87°F) – Boiling
Point
Above Boiling Point
Humidity control above boiling point:
The pressure sensor P1 is supplied with 12V DC. When the fan wheel is
at a stand still, the offset voltage is between 0,45 - 0,55V DC.
(possible error Service 36 when no power
supply or defective)
This differential pressure will be higher when:
1. The temperature in the cabinet gets colder
2. The amount of humidity in the cabinet gets lower
3. The speed of the fan wheel increases
NOTE: The given values below are only average values and shall demon-
strate the relationship of pressure values P1 to change in speed, tem-
perature and humidity.
Values might be different up to 0,4V with left and right turning fan
wheel.
61, 101, 201 (60)
Cold and dry
Warm and humid - Steam @boiling point
Hot and humid - Combination 180°C (356°F)
62, 102, 202
Cold and dry
Warm and humid - Steam @boiling point
Hot and humid - Combination 180°C (356°F)
If the value (grey) at standard speed and in cold condition (below 60°C) is below 2V, check the P1 hoses for block-
age behind the fan wheel and proper positioning at the sensor.
(possible error Service 37).
The pressure sensor must be installed horizontally!
Handle with care! The pressure sensor is very sensitive to mechanical shock!
V08 en, SCC
Thermocouple B1 in the cabinet
Differential pressure applied to P1:
– Pressure sensor P1
–Thermocouple B4
– rpm of fan motor
S2
500 rpm
B2
(SCC_XS 60)
1,1V (0,7)
Y1
Y2
0,7V (0,6)
0,6V (0,6)
500 rpm
0,9V
0,7V
0,7V
B5
F3
M4
1000 rpm
(SCC_XS 60)
2,2V (1,3)
1,7V (1,0)
1,5V (1,0)
1250 rpm
2,7V
1,8V
1,6V
- 36 -
B1
F4
P1 Y5
M1
B4
S3
1450 rpm 1550 rpm
(SCC_XS 60) (SCC_XS 60)
3,1V (2,3) 3,5V (2,5)
2,0V (1,5) 2,2V (1,7)
1,7V (1,4) 1,9V 1,6)
1750 rpm 1850 rpm
4,6V 4.9V
2,8V 3,1V
2,7V 3.0V
B3