Burkert 178 354, Operating Instructions Manual

Page: 34 / 89

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english
seTTing The MiniMuM and MaxiMuM cOil currenT
start of flow
Set the minimum coil current I
1
(AdJ = LO mA) via the arrow keys so that
the valve just starts to open.
Start with a current value at which the valve is still reliably closed and
increase the coil current with the arrow key until the flow indicator
detects a flow for the first time.
Reduce the coil current by a few mA with the key until the valve is
reliably closed again.
Confirm the minimum coil current I
1
with the -key.
Maximum flow rate
Set the maximum coil current I
2
(AdJ = HI mA) via the arrow keys so that
the maximum flow rate is just achieved.
Increase the coil current with the arrow key until the maximum flow
rate is reached and a further increase in the current does not result in a
further increase in flow rate.
Reduce the coil current with the arrow key until the flow rate starts
to drop noticeably again and confirm this value with the
-key as the
maximum coil current I
2
(AdJ = HI mA).
indicative current values, depending on the valve type
For the current values of the start of opening and the maximum flow rate
there are default values for each valve type stored in the menu. These values
are only indicated values depending on the nominal size of the valve and
pressure ratio.
In the menu item ADJ the valve must be set to the nominal size of the valve
and the current pressure.
For all direct-acting proportional valves (i. e. all types with the exception of
Type 622), the current value I
1
for the start of opening drops with increas-
ing inlet pressure; with an increasing pressure drop through the valve, the
value I
2
at which the maximum flow rate is achieved also decreases.
For the pilot-controlled valve, Type 622, the current value for the start of
opening increase with increasing inlet pressure; with an increasing pressure
drop through the valve, the value I
2
also increases.
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