Temperature Sensor (Kty 10); Measured Values; Grinder; Doser - Saeco Classic Service Manual

4. FUNCTION/TIMING

4.6. Temperature sensor (KTY 10)

The temperature sensor is a temperature-sensitive resistance mechanism, converting the instantaneous water
heater temperature into an electrical signal which is measurable by the CPU.
The CPU compares this signal with the programmed reference signal and, depending on the outcome of the
comparison, controls the instantaneous water heater output.
The resistance applied has a positive temperature coefficient; i.e. higher instantaneous water heater
temperature - higher sensor resistance.
The table below indicates the trend in resistance values in relation to the temperature.

Measured values:

Temperature Resistance ( )
0
15
20
40
90
100
130
140
At room temperature the resistance is 1.9K .

4.7. Grinder

The grinder is a conical grinder with upper and lower grinding disc. The grind level is set by adjusting the
height of the upper grinding disc by means of the screw thread.
If the grinding discs are drawn apart by turning the grind level adjusting ring (turning anti-clockwise), the
grind is coarser, while turning the adjusting ring clockwise will result in a finer grind.
ATTENTION: Adjust the grind level only when the grinder is in operation!
The grinder operates with a direct current motor and the grinding disc rotation speed is determined by a
gearmotor. The grinder motor operates with a voltage of 260 V.

4.8. Doser

The coffee quantity for the current coffee process is portioned (dosed) in the doser chamber; a higher dose
results in a stronger (more concentrated) coffee. A lower dose results in a weaker (less concentrated coffee).
The doser is controlled by a microswitch. The ground coffee is pressed into the doser chamber from the
grinder. When the dosing chamber is full, the microswitch is activated and transmits to the CPU the signal to
turn the grinding motor OFF.
Grinding is stopped, the dosing magnet engages (2x), opens the dosing flap and the coffee falls into the
brewing unit.
If the dosing microswitch is not activated within 20 seconds from start of the grinder motor, the coffee beans
low signal appears.
The dosing quantity is set automatically by shifting the doser housing wall together with its microswitch.
Page 22/22
Resistance trend ( )
1629
1845
1922
2246
3168
3366
3979
4188
REV.4 SEPT.2003
0
216
77
324
922
198
613
209
ROYAL
Saeco International Group