Saeco RI9722/11, Service Manual

Page: 44 / 224

4. FUNCTION/TIMING INCANTO S-CLASS
Page 4/9 REV.1 FEB.2005 Saeco International Group
4. Function
4.1. Gearmotor
The gearmotor is connected to the power element of the circuit board via the auxiliary heating system. In
order to perform forwards and backwards movements, the gearmotor is controlled alternately with a
positive and negative half wave. The voltage is limited by the electronic system to approx. 30 to 35 V. The
electronic system of the motor is switched off in the event of an overload. The overload is detected through
the increased power input to the gearmotor during the stoppage. The red fault LED/brewing unit lock
indicator turns on.
If the brewing unit is locked in the upward movement, the cycle is interrupted after about 8 seconds and the
control system attempts to move the brewing unit to the idle position. This occurs, for instance, when too
much powder is present in the brewing chamber. If the brewing unit is locked in the downward movement,
the motor turns off after 8 seconds and the machine is locked. This situation is indicated by the flashing
fault LED / brewing unit lock indicator. The machine must be turned off and the cause of the lock
removed.
Note: The gear wheel must always be installed so that MS1 and MS2 are positioned at the long
section of the switching cams!
4.2. Gear resistor
The heating system of the thermoblock with green marking at the connection point acts as resistor for the
gearmotor. The gearmotor cannot function in the event of a defective heating system.
The heating system (resistor) has a resistance of approx. 130 Ohm.
4.3. Water level indicator
The water level in the water tank is monitored by a float fitted with a magnet core. If the water level is too
low, the magnet is no longer within the range of the reed contact, which transmits the low water level
signal to the CPU (Water Low indicator).
MS2
Brewing position
Gear cam 2
Brewing position
MS1
Home position
Gear cam 1
Home position