S&C IntelliRupter PulseCloser - Page 47

T/A
D/T
Zero
100%, Trip
0%, Reset
% of Trip
Time
T/A method keeps ratcheting up toward a trip for an intermittent fault.
D/T keeps resetting in between current spikes.
Ground
Current
SEF Pickup
Figure 35. Ground Overcurrent Element reset characteristics.
Phase Overcurrent Alert
This feature is based on the Phase Overcurrent Trip element, but it is not a protection
element and will not lead to any IntelliRupter fault interrupter action. Instead, it is used
to notify the user via the Operation screen and SCADA that an overcurrent condition
exists. To enable this feature check the Phase Alert check box and enter the current
threshold. (Range: 6-16,000; Step: 1)
Ground Overcurrent
The Ground Overcurrent element trips the IntelliRupter fault interrupter when the
computed residual of the three-phase elements exceeds the pickup value selected for the
time value set by the Inverse Curve or Denite Time settings. See Figure 35.
Ground Check box—Select to congure this element.
Inverse Segment—Select from the drop-down list of inverse curve names or select the
None option. When the None option is selected, only the Denite Time settings are used.
Min. Trip—This is the current (in primary amperes) at which the inverse curve begins
timing. (Range: 6-16,000; Step: 1) The stated maximum is for 15-kV IntelliRupter fault
interrupters; 27-kV and 38-kV models are limited to 12,500 amps maximum.
Min. Time—This is the time (in seconds) dening the fastest response of the inverse
curve portion of the TCC curve. (Range: 0.000-100.000; Step: 0.001)
Time Mult—This is the time multiplier for the inverse curve. (Range: 0.01-15.00; Step: 0.01)
Time Adder—This is the time adder for the inverse curve. (Range: 10.000-100.000;
Step: 0.001)
Low Cutoff—This is the current (in primary amperes) at which the TCC curve begins
timing. This value must be equal to or greater than the lowest pickup value of the inverse
curve, the Denite Time 1 element, and the Denite Time 2 element. (Range: 6-16,000;
Step: 1) The stated maximum is for 15-kV IntelliRupter fault interrupters; 27-kV and 38-kV
models are limited to 12,500 amps maximum.
S&C Instruction Sheet 766-530 47
Protection Setup