Siemens siprotec 7SA6, Manual

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Configuration
5-22
7SA6 Manual
C53000-G1176-C156-2
Filtering / Contact
Chatter
Suppression For input indications (single point indications
SP
, double point indications
DP
), trans-
former tap indication
TxTap
(if available), filter times may be entered (pick-up and
drop-out delays) to suppress momentary changes in potential at the binary input (e.g.
contact chatter), refer also to Figure 5-16 and 5-17. Filtering occurs during an input
change of state, with the same setting values whether coming or going. Information is
only distributed when the new state continues to exist after a preset time interval (in
milliseconds). The setting range is from 0 to 86,400,000 ms or 24 hours. Whether or
not the filter interval is restarted for each change of state during the filtering (filter re-
triggering) is selectable.
It is also possible to set chatter suppression for each indication (Figure 5-16 and 5-17).
The contact chatter settings, themselves, are set the same for all input indications (see
Sub-section 5.2.6).
Transformer Tap
Changer (TxTap) The transformer tap changer position is communicated, via binary inputs, in a speci-
fied encoding format (maximum of 62 positions). Only binary inputs that are in direct
order with regard to numbering can be used.
For the encoding formats available (binary code, BCD code, “1-of-n” code), four set-
tings (number of taps, number of bits, display offset, and tap interval) may be pro-
grammed. Their bit pattern corresponds to an individual transformer tap changer po-
sition which is represented in the device display and in the indication buffers (Figure
5-18).
If “Moving contact” is activated, the tap position is valid and accepted only when the
moving contact of the tap changer has signalled its final position.
Figure 5-18 Information Properties Example for Information Type “Transformer Tap
Changer” (TxTap)
If none of the available encoding formats is selected, each individual tap changer po-
sition may be set in a table. The table is accessed after the pull-down menu
Table
for
encoding is opened, by selecting the button at the side.