english -
21
R
espresso coffee machine - technician instructions
6. AUTOMATIC WATER ENTRY
The Automatic water entry system is for checking the boiler level. It is composed of:
• probe inserted in the boiler
(1)
, composed of a stainless steel rod
• standard control unit
(2)
on SAE-SME machines, electronic level regulator on the
other versions
(3)
;
• hydraulic circuit with a solenoid valve controlled by the regulator.
The electronic control unit controls the level of water in the boiler. When the level of water
in the boiler drops, the contact with the probe is interrupted. The control unit sends and
impulse to the entry solenoid valve and to the motor pump, which act to restore the normal
level of water in the boiler.
To avoid possible flooding due to machine malfunctions or leaks in the hydraulic circuit, the
electronic control unit includes a timing device that cuts off automatic filling after a certain
time (roughly 2 minutes). The LED
(4)
located on the front of the machine body comes
on to indicate activation of this system. During the installation of machines with three or
four groups the initial water filling time may exceed the established time limit. In this event,
just switch the machine off and then back on to restore normal operating conditions.
8. VOLUMETRIC DOSING
The volumetric dosing device installed on the SAE-SME electronic machines serves the
purpose of measuring the quantity of water sent to the group of espresso delivery.
The dosing device generates an electrical impulse which is sent to the electronic control unit. This
impulse is read by the control unit and memorized during the programming of the dose.
The flashing of the LED
(5)
indicates that the electrical impulse has been sent from the
dosing device to the control unit.
1
2
3
4
5
ATTENTION
Always check the level of the water in the boiler by means of the level-check
window placed on the front of the machine.
7. ELECTRONIC CONTROL UNIT
The electronic control unit is installed on machines with volumetric dosing device. Its
purpose is to electronically control the coffee dose by means of the water flowing
through the dosing device and to check the filling of the water in the boiler.
Some versions of the control unit are set up to be connected to the delivery account-
ing systems by means of a specific interface device.
NOTE
Some units include a button lithium battery.
When it needs replacing, disconnect the machine from the power outlet and
open the central unit placed inside the equipment.
Dispose of the battery in compliance with the collection regulations of the
country of use.
