GP43/44
Datum 10.08.2011
Art.Nr. 79804
Änd. Stand 243/11
11
Fig. 12: Aligment
Current
Distance
20mA
4mA
(Po)
(Pe)
0
7.5 What to do if... (Instrument transformer)
...the counting direction is wrong?
You can:
•
either mechanically change the counting direction
(by ordering / modifiying the counting direction
at SIKO),
•
or by inverted interpretation of the 4 to 20 mA
current (4 mA would then correspond to the end po-
sition; can be achieved via software programming).
... if the instrument transformer's start / end va-
lue cannot be set to 4 / 20 mA?
•
the potentiometer's setting range is perhaps to
small (wiper moves below the minimum range
15...90% and sweeps a too small restistance
range).
•
check, whether you can do with a smaller current
range; otherwise adjust the gear's input ratio
accordingly ( by ordering / changing the counting
direction at SIKO).
What to do if... (Potentiometer)
... an undefined value is displayed?
•
Carry out re-alignment or precise alignment.
Undefined values can be caused by cable breaks.
8. Starting
Please ensure that the instructions given in chapter
5 and 6 regarding mechanical and electrical con-
nection are followed. This will ensure correct instal-
lation and the operating reliability of the device.
Before starting check again:
•
correct polarity of the supply voltage
•
correct cable connection
•
correct mounting of the device
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.
Alignment
1. Move axis to start position.
2. Turn left potentiometer (Po) until start value
(4 mA) is measured.
3. Move axis to end position.
4. Turn right potentiometer (Pe) until end value
(20 mA) is measured.
The steps 1 to 4 are to be repeated until the values
are counterbalanced.