Sel 411L - Page 435

P.3.327
Date Code 20151029 Protection Manual SEL-411L Relay
Protection Functions
Protection Application Examples
ESTUB := NOT IN208 Enable Stub Bus Protection (SELOGIC control
equation)
Mho Phase Distance Element Reach. Reach settings for Zones 1 and 2
(phase and ground) follow typical guidelines of 80 percent for the
underreaching Zone 1 and 120 percent for the overreaching Zone 2:
At Relay S, we would then have the following:
Zone 1 Reach = 2.51  • 0.80 = 2.01 
Zone 2 Reach = 2.51  • 1.20 = 3.02 
Z1MP := 2.01 Zone 1 Reach (OFF, 0.05–64 , sec)
Z2MP := 3.02 Zone 2 Reach (OFF, 0.05–64 , sec)
Z1D := 0 Zone 1 Time Delay (OFF, 0.000–16000 cycles)
Z2D := 20 Zone 2 Time Delay (OFF, 0.000–16000 cycles)
Mho Ground-Distance Element Reach. Set ground elements with the
same reach as for the phase elements.
Zone 1 Reach = 8.39  • 0.80 = 6.71 
Zone 2 Reach = 8.39  • 1.20 = 10.07 
Z1MG := 6.71 Zone 1 (OFF, 0.05-64 , sec)
Z2MG := 10.07 Zone 2 (OFF, 0.05-64 , sec)
At Relay R, we would then have the following:
Zone 1 Phase Reach = 3.14  • 0.80 = 2.51 
Zone 2 Phase Reach = 3.14  • 1.20 = 3.77 
Zone 1 Ground Reach = 6.71  • 0.80 = 5.37 
Zone 2 Ground Reach = 6.71  • 1.20 = 8.05 
Z1MP := 2.51 Zone 1 Reach (OFF, 0.05-64 , sec)
Z2MP := 3.77 Zone 2 Reach (OFF, 0.05-64 , sec)
Z1MG := 5.37 Zone 1 (OFF, 0.05-64 , sec)
Z2MG := 8.05 Zone 2 (OFF, 0.05-64 ,sec)
Zero-Sequence Compensation Factor
Select AUTO for the Zero-Sequence Compensation Factor Magnitude.
We would have the following at both terminals:
k0M1 := AUTO Zone 1 ZSC Factor Magnitude (AUTO, 0.000–10)
The relay displays the following values for k0M1 and k0A1:
k0M1 := 1.696 Zone 1 ZSC Factor Magnitude (AUTO, 0.000–10)
87LGPS := 0.3 Pickup 87LG Element, Sec. Mode (0.1–2 pu)
87LGRS := 7.2 Radius 87LG Element, Sec. Mode (1.2–8)
87LGAS := 234 Block Angle 87LG Element, Sec. Mode (90–270°)