Case 2—This case shows why Definite Time 1 must be faster than the Inverse Curve
Segment. If it is not the definite time will have the unexpected effect of slowing the
response time.
Inverse Curve Segment: SEL U5; Min Trip = 280 A; Min Time = 0; Time Mult = 0.1; Time
Adder = 0; Low Current Cutoff = N/A
Definite Time 1: Min Trip = 281 A; Min Time = 0.05
See Figure 32 on page 44.
Case 3—This case shows an inverse curve altered by a Definite Time 1 that complies
with the order of precedence.
Inverse Curve Segment: SEL U5; Min Trip = 280 A; Min Time = 0; Time Mult = 1.0; Time
Adder = 0; Low Current Cutoff = N/A
Definite Time 1: Min Trip = 3000 A; Min Time = 0.02
See Figure 33 on page 45.
Case 4—This case shows an inverse curve altered by a Definite Time 1 and Definite Time
2 that complies with the order of precedence.
Inverse Curve Segment: SEL U5; Min Trip = 280 A; Min Time = 0; Time Mult = 2.0; Time
Adder = 0; Low Current Cutoff = N/A
Definite Time 1: Min Trip = 2,000 A; Min Time = 0.05
Definite Time 2: Min Trip = 5,000 A; Min Time = 0.0
See Figure 34 on page 46.
42 S&C Instruction Sheet 766-530
Protection Setup