La Marzocco Strada, Руководство пользователя

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4. FLOWMETER
The flowmeter measures the volume of water passing through the groups.
The flowmeter consists of an impeller or wheel that contains two small magnets, and a body or
housing that contains a precision orifice or jet that controls the amount of water that can flow
into the flowmeter.
When water enters the flowmeter, the impeller spins and the magnets pass under the
electromagnetic field.
Each time a switch in the field closes a pulse is sent to the microprocessor to be counted.
5. AUTOFILL SYSTEM
The autofill system maintains the water level in the rear or steam boiler.
The autofill system consists of a sensor or probe, and a two-way solenoid valve.
The sensor is a metal probe that is insulated from surrounding metal with a teflon seal and is
inserted into the boiler.
The microprocessor reads this post though a lead or wire.
The microprocessor is programmed to detect a ground or earth signal from this sensor.
If it does not, it opens the two way solenoid valve and allows water to fill the boiler.
When the water level reaches the metal post the microprocessor can detect the ground or
earth signal and closes the two way solenoid valve.
6. VACUUM VALVE
The vacuum valve avoids the steam to escape from the boiler until sufficient steam pressure
develops to lift the cone and seal the boiler.
This valve prevents a false pressure reading when a machine is initially heating: as hot as it
heats, the water expands.
The pressure switch cannot detect the difference between air pressure or steam pressure.
By allowing the air pressure that develops from the expanding water to escape, a true steam
pressure can build as the machine continues to heat.
This valve also reduces any possibility of contaminating the steam boiler (milk suction through
the vacuum effect caused by the steam pressure decrease).
7. EXPANSION VALVE
The expansion valve relieves front boiler pressure at about 12 bar.
The expansion valve is located in the drain box, which is underneath the drip tray.
The expansion valve consists of a valve body or housing, a valve seal and spring which are
enclosed in an adjustable, and a brass barrel.