The Radial System distribution system, as shown, requires both relays Curves are Extremely Inverse (EI) operation [IEC 60255].
If the relay at Bus B is set to Back up protection of the relay at Bus A using the difference of working time (Grading Margin) equal to 0.35 seconds when the Fault occur within the Primary Zone (F2) of the relay of Bus B itself, then How much time the relay at Bus B will require to pick up,
A. 0.433 seconds
B. 0.350 seconds
C. 0.137 seconds
D. 0.260 seconds
Show Answer
Answer: C
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