Saeco MAGIC ROMA - Function; Gearmotor; Heating Plate; Gear Resistor

MAGIC 4. FUNCTION/TIMING
Saeco International Group REV.5 SEPT.2004 Page 9/12
Gear
Motor
Small
gear
wheel
Large
gear
wheel
Home position
setting microswitch
Home position
setting cam
Home position
setting cam
red blue
black
red
black
brown
Brewing position
setting microswitch
4. Functioning
4.1. Gears
The gearmotor is a direct current motor and is controlled by the CPU at approx. 30 – 35 V.
In order to perform forward and backward movements, the gearmotor is controlled alternately with a
positive and negative half wave.
In the event of overload the motor's electronic system switches off after 8-10 sec. and the machine is
stopped. This situation is indicated by the flashing brewing unit indicator light. In digital indicator systems -
display indicator: brewing unit locked.
Important: During installation of the large gear wheel care must be taken that the marking on the large gear
wheel always faces the direction of the small gear wheel axis, and that both limit switches are
positioned in the larger segment between both switching cams.
If the motor is replaced, it is important that the blue cable (-) is fitted onto the motor connection
near the writing "Italy" (+ and – are not marked).
4.2. Heating plate / Gear resistor
4.2.1. Magic
The heating plate is operated with a wave packet control system. The ratio of the power-on time is approx.
1:40 (0.1 sec on, 3.9 sec. off). The heating plate is turned on by means of the corresponding button on the
control panel. It is only active when the machine is not operational. The heating plate output is approx. 437
W.
In order to reduce the total power output of the machine, the heating plate is turned off during the heating
stage.
The heating plate can act as a resistor for the gearmotor. In the event that several coffees are brewed
consecutively, the heating plate warms up without being turned on. The heating plate is protected against
overload by 2 thermal fuses.
If one of the thermal fuses is compromised or the heating plate is defective, the gearmotor also does not
function.