Siemens 7SJ82, Manual

Page: 566 / 1638

[dwerdwdl-110512-01.tif, 1, en_US]
Figure 6-124 Correction of the Transmission Characteristic Curve of a Core Balance Current Transformer
Ground-Fault Indication, Stabilization at Intermittent Ground Fault
The indication
Ground fault
indicates the ground fault and manages the ground-fault log (see Ground-
Fault Log, Page 566 ). The corresponding information of the stages used is accessed for the generation of
this indication.
The indication
Ground fault
contains the direction information, independent of the parameterized
working direction of a stage. The indication is thus suited for transfer to a station.
To avoid a flood of indications in case of an intermittent ground fault, a maximum of 30 status changes of this
indication is logged per ground fault. An intermittent ground fault must be treated as a ground fault so that
the stabilization can take action. This is ensured with the parameter
Dropout delay
, by the dropout of the
indication
Ground fault
being delayed. If the next ignition of the ground fault takes place during the
dropout delay, the indication does not drop out and the log remains open.
i
i
NOTE
The
Ground fault
indication in the general stage must be routed to the ground-fault log. If not, you can
meet an overflow of the ground-fault log when an intermittent ground fault occurs.
Ground-Fault Log
Ground faults can be recorded in a designated buffer, the ground-fault log. As long as the
Operate &
flt.rec. blocked
parameter is set to
yes
, all indications routed into the ground-fault log are written in
the ground-fault log.
The criterion for opening the ground-fault log is the raising of any indication which is routed to the ground-
fault log, for example, the indication
Ground fault
. The criterion for closing is the clearing of all routed
indications.
Related Topics
You can find general notes on the ground-fault login chapter Indications under 3.1.5.4 Ground-Fault Log .
Value Indications
If the following value indications can be calculated, they are written into the log (ground-fault log or fault log)
at the time of the 1st raising ground-fault indication and the 1st operate indication of any stage.
•
3I0 (value)
•
3I0 active component
•
3I0 reactive component
Protection and Automation Functions
6.15 Sensitive Ground-Fault Detection
566 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017