Profitec DRIVE Bedienungsanleitung Seite 143

10.3.4 Pre-infusion
Pre-infusion ensures that the ground coffee in the portafilter is completely
moistened once before extraction is carried out at high pressure.
There are various possibilities for pre-infusion. The flow control can be used
to perform a single manual pre-infusion without interrupting the pumping
process (see Chapter 5.2.4, „Flow control").
sufficient, there is also the possibility of actively (with pump activity) and/or
passively (without pump activity) influencing the pre-infusion.
How pre-infusion works
At the start of the espresso extraction process, the pump actively builds
the pressure up for a predefined period of time. Before the pump pressure
has reached 9 bar, the pump interrupts the activity for another predefined
period of time. During this passive phase, the hot water completely soaks the
ground coffee. After soaking is complete, the extraction is started at 9 bar.
Example
Active pre-infusion = 4 seconds, passive pre-infusion = 5 seconds:
Pump activity starts for 4 seconds after the start of espresso extraction.
After these 4 seconds, the pump activity is interrupted for 5 seconds in order
to moisten the ground coffee. After these 5 seconds have elapsed, the pump
starts up again and the espresso extraction is started at 9 bar.
Active versus passive pre-infusion
Active pre-infusion is recommended only when operating the machine in
water tank mode, as the pressure from the water tank is not sufficient for
completely soaking the ground coffee. Exclusively passive pre-infusion
is recommended for operation in mains water mode. The line pressure is
sufficient for moistening the ground coffee within a preset time.
EN - 142
Passive pre-infusion
This icon appears when passive pre-infusion is in
progress.
Active pre-infusion
This icon appears when passive pre-infusion is in
progress.
If this pre-infusion is not
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