Siemens SIPROTEC 4 7UT6 Series Manual page 141

For the zero sequence current 3I0p the characteristic can be selected independently of the characteristic used
for the phase currents.
The pickup values of the stages Ip (phases) and 3I0p (zero sequence current) and the time multipliers valid
for each of these states can be set individually.
Figure 2-71 and
currents Ip and for the zero sequence currents 3I0p.
[logik-umz-abh-amz-phasenstrom-iec-kennlinie-121102-st, 1, en_GB]
Figure 2-71
SIPROTEC 4, 7UT6x, Manual
C53000-G1176-C230-5, Edition 09.2016
Figure 2-72 show the logic diagrams of the inverse overcurrent time protection for phase
Logic diagram of the inverse overcurrent protection for phase currents — example of IEC char-
acteristic (simplified)
2.4 Time Overcurrent Protection for Phase and Residual Currents
Functions
141