Application And Setting Notes - Siemens 7SJ82 Manual

Capacitor Bank Protection
7.4 Current-Unbalance Protection for Capacitors, 3-Phase
[dwfehlerortinf_iunsy-020913, 1, en_US]
Figure 7-10
The black dot indicates the orientation of the current transformer. For the connection of the current trans-
former shown in the previous figure, the following definition applies:
•
Group 1: C1 and C4
•
Group 2: C2 and C3
In order to determine the fault location (group 1 or 2) correctly, use the parameter Capacitor element
type (in FB General of the Capacitor bank function group) to tell the device whether the elements of the
capacitor bank have internal fuses or not.
The angle reference of the unbalanced-current phasor to the reference current I
direction of the unbalanced current and, thus, the affected group is determined. If the direction cannot be
determined with confidence, an appropriate indication will be generated.
7.4.3.2

Application and Setting Notes

Parameter: MP selection
•
Default setting (_:13501:81) MP selection = None
With the MP selection parameter, you can select from a list the measuring point that is connected to the
I Unbalanced interface of the Capacitor bank function group.
The setting applies equally to all stages of the function.
In the default setting, a measuring point is not selected. You must select a measuring point. If you do not
select a measuring point, an inconsistency is indicated via the read-only parameter Consistency failure.
Parameter: Automatic compensation
•
Default setting (_:2311:101) Automatic compensation = no
The parameter applies equally to all stages of the function that work with compensated measurands.
984
Definition of the Fault-Location Information
is used to determine the
c
SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017