Siko SG5, Quick Start Manual

Page: 7 / 8

SG5 Datum 25.08.2010 Art.Nr. 83679 Änd. Stand 281/10 7
Fig. 8: Setting the trimming potentiometers
follower electronics
Fig. 7: Potentiometer connection MWU
Fig. 6: Potentiometer connection MWI
follower electronics
Color Designation
brown I+
white I-
5. Adjustment and Alignment
5.1 Potentiometer setting
Following correct connection, the wire-actuated
encoder outputs the actual resistance value after
switching on the operational voltage.
The measuring range of the potentiometer is mat-
ched to the total pull-out length of the wire. At
pull-out length 0mm (completely pulled-in), the
resistance value of the potentiometers is approx.
3%.
5.2 Alignment of the R/I transformer (MWI)
If the device is equipped with a resistance-current
converter, then the potentiometer resistance is
converted into a current of 4 to 20mA. The measu-
ring current is also used for feeding the instru-
ment transformer.
Ex works, the instrument transformer is aligned to
default values: 4mA for the start position (Po),
corresponding to the pull-out length of 0 mm
(completely pulled in), and 20mA for the end po-
sition (Pe), corresponding to the max. mm pull-
out length (completely pulled out) of the poten-
tiometer.
Via two trimmpotentiometer's Po and
Pe (see fig. 8) these values can be adjusted to
the application's actual start and end position.
Setting the instrument transformer
After releasing the hood snap (see capter 4.1), the
trimming potentiometers can be accessed.
Connection instrument transformer (MWI) load
against mass:
Connection instrument transformer (MWI) load
aUB:
4.4 Potentiometer with R/U transformer (MWU)
If you want to mount your own cable, please open
the unit as described in chapter 4.1 (max. cable-
ø3,5
+0,3
). Potentiomter connections will then be
accessible (fig. 7).
The instrument transformer provides an output
voltage of 0 to 10VDC.
Color Designation
brown +24VDC
white GND
green Uout
Trimmpotentiometer's Po is used to adjust a
current of 4 mA to potentiometer values of 0 to
15% of the total range.
Trimmpotentiometer's Pe is used to adjust a
current of 20 mA to potentiometer values of 90
to 100% of the total range.
The smallest available potentiometer range, in
which 4 to 20 mA are delivered, is hence 15% to
90% of the potentiometer's resistance range.
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