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1.2.7.6. Pumping system
This is a component that feeds the machine, raising the
water pressure to 8-9 bar for delivery of the coffee and
automatic filling of the boiler.
To adjust operating pressure proceed as follows:
- press a coffee delivery key;
- connect a pressure gauge with an end of scale of
more than 9 bar to the connection on the plumbing
circuit (see plumbing diagram);
- Adjust the pressure by turning the screw located on
the pump (1) so as to obtain a pressure of between 8
and 9 bar. Tightening the screw increases the pressu-
re, and loosening it reduces the pressure;
- check the pressure using the pressure gauge.
1.2.7.7. Valve group
The valves are devices whose purpose is
to ensure the safety and proper operation
of the machine.
Negative pressure valve
The negative pressure valve eliminates the air in the
boiler during the machine's warm-up phases.
Safety or pressure relief valve
The pressure relief valve guarantees that
the pressure in the boiler does not go
above 2 bar. If there is a malfunction, the
capacity of the valve is such that it can eli-
minate all the excess pressure from the
boiler.
6
Maintenance manual for technical assistance - LB 2800 - LB 2810
Expansion - non-return valve
This is a valve consisting of an expansion valve and a
non-return valve.
- Expansion valve: the cold water sent from the pump
to the heat exchanger is heated.
This heating causes an increase in the volume of
water. To limit pressure increases in the hydraulic cir-
cuit, the valve limits the maximum internal pressure of
the circuit to 12 bar.
- Non-return valve: its function is that of preventing the
backflow of water from the exchanger in the hydrau-
lic circuit.
Expansion
valve
1.2.7.8. Electronic control unit
Its purpose is to electronically control the coffee dose
1
by means of the water flowing through the dosing devi-
ce and to check the filling of the water in the boiler.
Furthermore, it also controls operation of the automa-
tic cappuccinatore.
This control unit is set up to be
connected
to
accounting systems by means
of a specific interface device.
1.2.7.9. Softener
Mains water contains insoluble salts, which cause the
build-up of lime scale deposits in the boiler and in
other parts of the machine. The softener makes it pos-
sible to eliminate or substantially reduce the presence
of these mineral salts.
The build-up of lime scale in the hydraulic circuit
and boiler inhibit thermal exchange, thus com-
promising proper operation of the machine.
Heavy incrustation in the boiler may cause long
machine shutdowns and in any case invalidate
any guarantee.
Manual code 10066574 / Rel. 0.00 / March 2009
Non-return
the
delivery
valve
Attention
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