Problem $20$

Discuss the standard for selecting the current transformer and setting of overcurrent relay in case of

$1-$ Instantaneous trip for electromagnetic relay.

$2-$ Definite time delay setting electromagnetic relay.

$3-$ Groundingrelay.

$4-$ Digital relays.

For radial system shown in Figure, with the help of the time dial setting curves given, calculate:

The CT$\text{'}$s ratio at each bus and check it$.$

The time$-$delay over$-$current relay settings at each bus.

The Instantaneous Relay settings at each bus.