1.3.6.2. Brewing unit
The brewing unit and the heat exchanger are funda-
mental components to obtain espresso coffee.
Specifically the function of the unit is coffee dispensing.
In this system the brewing unit (1) is heated by a ther-
m
osiphon circuit (2) connected to the heat exchanger
(3). The same water is used for coffee brewing:
- activation of the solenoid valve and the pump allows
cold water to enter the exchanger (3) via the injector
(4);
- heated water is carried to the unit (1) for brewing from
the exchanger (3);
- the pump allows water pressure to be increased up to
8-9 bar for brewing.
In order to increase or decrease the temperature of the
coffee in the cup, water temperature in the boiler must
be changed (see section 6.3.11).
N
ote
I
f the water temperature in the boiler is decreased
but the coffee is still too hot, the reducer (5) supplied
with the machine must be put on the pipe.
1
.3.6.3. Automatic water entry system (A.E.A)
The automatic water entry system checks the water level
in the boiler.
The system is composed of:
- a probe inserted in the boiler (A) which is composed
of a stainless steel rod;
- an electronic control unit (B);
- a pump that, with the AEA solenoid valve, allows the
water flow into the boiler;
- a AEA solenoid valve.
The electronic control unit controls the level of the water
in the boiler.
When this level drops the contact with the probe is in-
terrupted; the control unit sends an impulse to the inlet
solenoid valve and the power pump, which restore the
normal level of water in the boiler.
To avoid possible flooding due to machine malfunctions
or leaks in the water circuit, the electronic control unit is
equipped with a timing device that cuts off the automa-
tic filling after a maximum period of 120 seconds.
3
2
1
Water inlet
Coffee
dispensing
3
4
5
A
B
At resting
position
During
dispensing
4
Manual code 10066574 / Rel. 2.00 / February 2012
Maintenance manual for technical assistance
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