1.2.7.3. Automatic Water Entry (A.E.A)
The Automatic Water Entry system is for checking the
boiler level.
It is composed of:
- probe inserted in the boiler (
A
), composed of a stain-
less steel rod;
- electronic control unit (
B
);
- a pump which, along with the AEA solenoid valve,
allows water to flow into the boiler.
- AEA solenoid valve.
The electronic control unit controls the level of water in
the boiler. When the level drops, the contact with the
probe is broken. The control unit sends an impulse to
the inlet solenoid valve and to the motor pump, which
are activated to restore the normal level of water in the
boiler.
To avoid possible flooding due to machine malfun-
ctions or leaks in the hydraulic circuit, the electronic
control unit includes a timing device that cuts off auto-
matic filling after a maximum operating time of 120
seconds.
B
1.2.7.4. Volumetric dosing device
The volumetric dosing device installed on the EVD
electronic machines serves the purpose of measuring
the quantity of water sent to the espresso delivery
group.
The dosing device generates an electrical impulse
which is sent to the electronic control unit. This impul-
se is read by the control unit and memorized during the
programming of the dose.
The flashing of the LED (
1
) indicates that the electrical
impulse has been sent from the dosing device to the
control unit.
1
1.2.7.5. Checking boiler temperature/pressure
The temperature (and as a result the pressure) in the
boiler is controlled by a special NTC sensor located on
the boiler (
X
).
This sensor constantly sends information to the elec-
tronic control unit, which in turn activates or deactiva-
tes the heating element by means of a power triac.
The default temperature is set in the factory at 120°C.
If you want to change this value, you can do so by
means of the procedure described in the chapter
“Programming of boiler temperature”.
Manual code 10066574 / Rel. 0.00 / March 2009
Maintenance manual for technical assistance - LB 2800 - LB 2810
5
A
X
