CPI COTI - Page 127

Secon 8 - Espresso System
Technical Manual
Pressure Boiler
The pressure boiler has a capacity of 17  oz and is ed with a 1.1kW heang element.
Cold water is diused as it enters the boiler and heated water exits the boiler through the
top coupling. A reseable temperature cut-out is mounted externally on the front of the
boiler as a safety feature. A thermistor is mounted in the top of the boiler to measure
water temperature.
3 Way Valve (Espresso Valve)
Supplies heated water to the CoEx® brewer when an espresso or freshbrew drink has been
selected.
2 Way Valve (Pressure Valve)
This valve is normally open exposing the system to the 3 bar mechanical relief valve. It is
closed during vends to allow higher pressures to be achieved within the system.
Relief Valve - 3 Bar (Mechanical)
The 3 bar pressure valve is a mechanical safety valve. The valve allows for heat expansion
while the machine is in stand-by mode.
By-pass Valve - 12 Bar (Mechanical)
The 12 bar valve is a mechanical safety valve. The valve acvates and sends water to the
waste tray if the system pressure exceeds 12bar.
Non Return Valve
The non return valve allows water to ow in one direcon which smooths the ow which
allows accurate reading of the ow meter.
Grinder Mechanism (Not Shown On Water Flow Diagram)
The grind mechanism consists of a 110V AC conical grinder with a manual adjustment.
When an espresso based drink is selected the grinder will run for the programmed me
grinding beans and feeding the brewer. The grinder is ed with a manual adjusng
mechanism which allows the engineer to vary the grind of the coee in order to sasfy
consumers’ taste preferences.
CoEx® Brewer (Not Shown On Water Flow Diagram)
The brewer unit is capable of receiving between 5 and 9 grams of ground coee. Once the
coee has been ground and dispensed into the brewer unit the 24Vdc brewer motor drives
the brewer to the vend posion using current sensing as it’s control. The coee is
compressed into a cake and water is pumped through the brewer. When the required
amount of water has passed through the brewer the now wet coee cake is squeezed,
removing most of the water from the cake and prevenng the brewer becoming
unnecessarily dirty. Aer the cake has been squeezed the brewer will deposit the cake into
the dry waste container and via a posion signal from a micro switch make a med return
to the stand-by posion.
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