⎯ 18 ⎯6 F 2 S 0 7 5 8FGRD140GRD140GRD140GRD140GRD140GRD1400.1s0.4s0.7s1.0s1.0s0.1s0.7s0.4s1.3s1.3sA BGRD140GRD140 GRD140GRD140Non-directionalNon-directionalFigure 2.1.10 Protection of a Ring Main CircuitPower Systems with Sources at both Line TerminalsIn power systems with sources at both line terminals as shown in Figure 2.1.11, the fault currentflows in from both terminals.c b a1 2 3G1 G2F2 F1Figure 2.1.11 Protection of a power system with sources at both line terminalsThe protection is performed by setting the directional element at points 1, 2 and 3 which operatesonly when the fault current (F1: solid lines) flows in from source G1 and at points a, b and c whichoperates only when the fault current (F2: dotted lines) flows in from source G2, with grading providedby time delays.

Toshiba GRD140 Instruction Manual

Product

Learn More

Legal