Protection Engineering Basics and Schemes Protection Engineering | Page 112

Plug setting multiplier is the minimum allowed load current flow across circuit. If Current increases from minimum allowed load current

PSM = Current Actual Secondary

Current CT Secondary

5.2.2 Time multiplier setting: is the minimum time required before relay pick up at time of faults.

We need Time current characteristic( TCC) for relay coordination.

5.3 Relay Types

Definite Time Relay Inverse Time Relay Instantaneous Time Relay

5.3.1 Definite Time Relay

The relay which operates with defined Time delay is Definite Time Relay.

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