S&C IntelliRupter PulseCloser - Page 41

Setting Examples:
Case 1—This case shows an inverse curve unaltered by a Denite Time setting.
Inverse Curve Segment: SEL U5; Min Trip = 280 A; Min Time = 0; Time Mult = 0.1; Time
Adder = 0; Low Current Cutoff = N/A
Denite Time 1: N/A
See Figure 31 on page 43.
Fault
Load
Zero
100%, Trip
0%, Reset
% of Trip
Time
E/M
D/T
E/M Reset Time
Fault
Load
Zero
Current
% of Trip
Time (not to scale)
E/M
D/T
E/M = Electromechanical Reset—Emulates old induction disk relay behavior.
D/T = Definite Time Reset—Better than E/M Reset because it is not affected
by load current.
Reset Time = Time for reset from 99.9% of trip to 0% (with no load current for E/M).
Common use of D/T is a fast 0.1 second reset time.
Current
0%, Reset
100%, Trip
Figure 30. Overcurrent Element reset characteristics.
NOTICE
There is an order of precedence between the Inverse Curve segment, Definite
Time 1, and Definite Time 2. Definite Time 2 must be higher in pickup magnitude
and faster in time than Definite Time 1. Definite Time 1 must be higher pickup
magnitude and faster in time than the Inverse Curve segment. See Instruction
Sheet 766-530, “S&C IntelliRupter® PulseCloser® Fault Interrupter: Setup,” for
more information.
S&C Instruction Sheet 766-530 41
Protection Setup