30
2016/01 Rev. 0.0
OptiFresh (Bean) NG 2.0
3.4.3 Wiper adjustment tips
Wiper tension correct (ideal)
If the brewer is adjusted correctly, the wiper moves
carefully over the upper side of the cylinder and pushes
the coffee residue off of the permanent filter. The wiper
bends slightly. When the wiper moves to the right the
coffee residue is transported to the waste bin. The
coffee residue drops from the right side of the brewer
straight into the waste bin.
Wiper tension too low
If the wiper moves over the upper side of the cylinder
it makes no contact with the permanent filter, so that
coffee residue is left on the filter. The wiper does not
bend at all. If the brewer unit is adjusted in this way it
can leak. If leakage is severe this can even result in
a vacuum loss, which means that the coffee residue
remains too wet (particularly for larger dispensing
volumes).
Wiper tension too high
If the brewer is adjusted too high, the wiper will stretch
and become clearly warped. Glancing along the long
side of the wiper will show a warped effect in the rubber.
The brewer is under extreme pressure and the sound
of the brewer motor audibly changes as a sign of the
severe load. This may even damage the wiper and
permanent filter!
During the complete brewer cycle, ball bearings from
the wiper arms and the tension member are under
severe pressure, resulting in bending. The ball bearings
may then break away, cracking the plastic brewer
housing.
Signs that the tension is too high:
The wiper is severely bent when it slides across the
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upper side of the brewer cylinder and permanent filter.
It appears as if the wiper arm is flattened between the
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brewer unit and the upper side of the brewer cylinder.
The brewer motor sounds as though it is running
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under extreme pressure.
The wiper pushes against the coffee residue when
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moving to the left.
Accumulation of coffee residue round the waste bin.
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