Oscillations in the back pressure in the metering line, which could lead to
undesirable variations in the metering volume, are automatically compen‐
sated for by the power end/drive. This results in dosing precision, which
otherwise could only be achieved with complex control circuits.
6.3 Capacity
The capacity set regulates the pump even in
‘Automatic’
mode (not with
SEK dosing heads).
By contrast, in conventional mode, the stroke length and stroke rate deter‐
mine the capacity. The stroke length can be adjusted between 0 and
100% via the continuous display or the menu. A metering volume of
between 30 to 100% is reproduced as being technically sensible (SEK
type: 50 - 100%)! The stroke rate can be set via the menu (not in "Ana‐
logue" operating mode) within a range of 0 - 12,000 strokes/h.
6.4 Self-Bleeding
Self-bleeding liquid ends (SEK types) are capable of independent priming
when a discharge line is connected and diverting existent air pockets via a
bypass. During operation they are also capable of conveying away gases
which are produced, independently of the operating pressure in the
system. It is also possible to dose precisely in a depressurised state due
to the integral back pressure valve.
6.5 Operating Modes
Operating modes are selected via the "Operating modes" menu.
Refer to the "Hierarchy of Operating Modes, Functions and Fault Statuses"
for the order of the various operating modes, functions and fault statuses.
‘Manual’
operating mode permits you to operate the pump manually.
This operating mode provides the option of controlling the pump externally
by means of potential-free contacts (e.g. by means of a contact water
meter). The "Pulse Control" option enables you to preselect the number of
strokes (a scaling or transfer factor of 0.01 to 99.99) in the
‘Settings’
menu.
This operating mode provides the option of working with large transfer fac‐
tors (up to 99,999). Metering can be triggered either by pressing the
[Clickwheel]
or by a pulse received via the "External control" terminal or
through a contact or a semiconductor switching element. It is possible to
pre-select a metering volume (batch) or a number of strokes using the
[Clickwheel]
in the
‘Settings’
menu.
The capacity and/or stroke rate is controlled via an analogue current signal
via the "External control" socket. The processing of the current signal can
be preselected via the control unit.
"Manual" operating mode
"Contact" operating mode
"Batch" operating mode
"Analogue" operating mode
Functional Description
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