Eaton EDR-5000 Nstallation, Operation And Maintenance Manual page 501

All ground current protective elements can be planned user defined as non-directional or as directional stages. This
means, for instance, all elements can be projected in forward/reverse direction.
For each element the following characteristics are available:
NINV (IEC/XInv);
•
VINV (IEC/XInv);
•
LINV (IEC/XInv);
•
EINV (IEC/XInv);
•
MINV (ANSI/XInv);
•
VINV (ANSI/XInv);
•
EINV (ANSI/XInv);
•
Thermal Flat;
•
IT;
•
I2T; and
•
I4T.
•
For tripping curves please refer to "Time Current Curves (Ground Current)" located in the Appendix.
The ground current can be measured either directly via a zero sequence transformer or detected by a residual
connection. The ground current can alternatively be calculated from the phase currents. However, this is only possible
if the current transformers are Wye-connected.
EDR-5000
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IM02602007E
501