16
of
54
TECHNICIANS' manual
Core200
2.8.1 Group
In this system, the dispensing group
(1)
is heated
by a thermosiphonic circuit
(2)
connected to the heat
exchanger
(3)
. The same water is used when dispens-
ing coffee which ensures that all coffees are the same
temperature:
•
The activation of the solenoid valve and the pump
allows cold water to enter the exchanger
(3)
through
the injector
(4)
;
•
the heating unit water is carried from the exchanger
(3)
to the group
(4)
for dispensing;
•
the pump allows the water flow pressure to increase
to 8-9 bar for dispensing.
The injector
(4)
and the flow reducer
(5)
are important
components for the operation of the dispensing group. To
increase the coffee extraction temperature, remove the
flow reducer
(5)
or replace it with one that has a bigger
diameter. To decrease the temperature, replace it with one
that has a smaller diameter. If necessary, the exchangers
can be replaced by removing the flange and disconnecting
the relative hydraulic circuit pipes. These operations should
be carried out when the machine has been switched off
and has cooled down: always replace the seals..
2.8.2 Boiler
The heating unit is made of copper sheet metal
(1)
.
The heat exchangers are assembled onto this unit and
are in turn connected to the dispensing group. The
water used for dispensing coffee is taken directly from
the heat exchanger. During the dispensing process, cold
water is sent inside the exchanger by means of the mo-
tor pump. Inside the heat exchanger, cold water and the
pre-existing hot water are mixed together in order to
obtain the optimal water temperature for coffee infusion.
The heating unit is electrically heated by an electric
heating element immersed in the water
(2)
.
2.8.3 Pressure relief safety valve
The pressure relief safety valve has a calibra-
tion of 1.9 bar in order to ensure that the pres-
sure in the steam heating unit does not exceed
2.1 bar. Should a fault occur, the capacity of the
valve is such as to be able to eliminate all the
excess pressure in the heating unit..
2.8.4 Negative pressure valve
The purpose of the negative pressure valve
is to prevent liquids from back-flowing through
the steam nozzle when they are being heated.
Furthermore, the excess air inside the heating
unit is removed during the machine's heating
phase.
3
Water inlet
Coffee
dispensing
5
3
4
DISPENSING IN PROGRESS
2
3
1
IDLE
2
1
Summary of Contents for 10003318
Page 53: ......
