Siemens SIPROTEC 7SJ62 Manual page 44

Functions
2.1 General
Polarity of Current Transformers (Power System)
At address 201 CT Starpoint, the polarity of the wye-connected current transformers is specified (the fol-
lowing figure applies accordingly to two current transformers). This setting determines the measuring direction
of the device (forward = line direction). Changing this parameter also results in a polarity reversal of the ground
current inputs I
Figure 2-2
Current ConnectionI4 (Power System Data)
Here, the device is informed whether the ground current of the current transformer starpoint is connected to the
fourth current input (I
dix A.3, Figure A-37). In this case, parameter 280 Holmgr. for Σi is set to YES. In all other cases, even if
the ground current of the own line is measured via a separate ground current transformer, the setting NO has
to be made. This setting exclusively affects the function „Current Sum Monitoring" (see Section 2.11.1).
44
or I .
N NS
Polarity of current transformers
). This corresponds with the Holmgreen-connection, (see connection example in Appen-
4
SIPROTEC, 7SJ62/64, Manual
C53000-G1140-C207-2, Release date 01.2008