[lo-cnt-EF-260314-01, 3, en_US]
Figure 7-9
Counting Faulty C-Elements
Activation/Blocking Counting
If at least one counter stage is enabled, the counter function is active. Furthermore, the counter function
works only if the automatic compensation is enabled.
In order to prevent counting as a consequence of the charging process, the counter function is implicitly
blocked for 250 ms by setting
I
unbal.,comp.
to 0 A, after the capacitor energizing has been detected.
Measurands, Counting
The measurand is the phase-selective compensated unbalanced current
I
unbal.,comp.
. If a single C-element is
faulty, an unbalance occurs in the H connection. This unbalance causes an unbalanced current; this means, a
small current jump is generated in the unbalanced current. Set the parameter Thresh. defective C-
elem., so that the current jump can be detected (refer also to 7.4.3.2 Application and Setting Notes). The
unbalanced current that was caused by the fault must exceed the threshold for 100 ms before the affected
group is determined and counting (incrementing the counter) takes place. There is one counter for each phase
and group. After the counting, the existing unbalance is compensated; this means, the unbalance is reset to
0 A. If the faulty group cannot be determined, the unbalance is also compensated.
Capacitor Bank Protection
7.4 Current-Unbalance Protection for Capacitors, 3-Phase
982 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
To Next Page
Loading...
