Automatic Water Entry; Volumetric Dosing; Pressure Switch - Wega Espresso Coffee Machine Use And Maintenance Manual

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6. Automatic Water Entry

The AEA system (Automatic Water Entry) is for checking the boiler level. It is composed of:
• sensor inserted in the boiler (1), composed of a stainless steel rod;
• control unit (2) standard on EVD machines, electronic level regulator on 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 (1) and to the motor pump (2), 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 30 seconds). 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.
WARNING
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. VOLUMETRIC DOSING

The volumetric dosing device installed on the EVD 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.

8. PRESSURE SWITCH

The pressure switch makes it possible to control boiler pressure by activating or bypassing
the heating element in the boiler.
Any calibration of the pressure switch which may be required can be carried out with the ma-
chine in operation by means of the screw (6) located on the body of the component.
WARNING
The internal contacts of the pressure switch may be subject to oxidization. It
is recommended to periodically clean the contacts with anti-oxidant spray.
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espresso coffee machine - instructions for technician
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