Schweitzer Engineering Laboratories SEL-311L, Instruction Manual, Page: 388 / 734

9-50 Setting the Relay Date Code 20010625
SEL-311L Instruction Manual
Phase Time-Overcurrent Element (See Figure 3.47)
Pickup (OFF, 0.50–16.00 A secondary {5 A nom.};
0.10–3.20 A secondary {1 A nom.}) 51PP = 3.33
Curve (U1–U5, C1–C5) (see Figures 9.1 through 9.10) 51PC = U3
Time Dial (0.50–15.00 for curves U1–U5; 0.05–1.00 for curves C1–C5) 51PTD = 2.00
Electromechanical Reset (Y, N) 51PRS = Y
See SEL
OGIC
torque control equation T51PTC.
Set 51PP to the same value as T51PP. Set 51PC to the same curve as T51PC. Set 51PTD so
that the maximum current seen by Station S for a fault at Station R (6081 A) asserts 51PT in the
Zone 3 delay time of 20 cycles.
6081
1 • 10
3
100
10
1
0.1
0.01
100 1 • 10
3
1 • 10
4
51P Overcurrent Protection
Z2 Time Delay
Primary Amps
51PT
Max. Phase Current
at Station S for a
Fault at Station R
Time
(sec
on
ds)
M311L140
Residual Ground Time-Overcurrent Element (See Figure 3.48)
Pickup (OFF, 0.50–16.00 A secondary {5 A nom.};
0.10–3.20 A secondary {1 A nom.}) 51GP = 2.0
Curve (U1–U5, C1–C5) (see Figures 9.1 through 9.10) 51GC = U3
Time Dial (0.50–15.00 for curves U1–U5; 0.05–1.00 for curves C1–C5) 51GTD = 2.0
Electromechanical Reset (Y, N) 51GRS = Y
See SEL
OGIC
torque control equation T51GTC.
Set 51GP to the same value as T51GP. Set 51GC to the same curve as T51GC. Set 51GTD so
that the maximum residual fault current seen by Station S for a fault at Station R (3538.9 A) asserts