Exam 11: Relaying Schemes and Techniques for Electrical Equipment Protection

Which is the main relay for protecting up to 90% of the transmission line-length in the forward direction?

The relay used for feeder protection is

In order that current should flow without causing excessive heating or voltage drop, the relay contacts should

To prevent mal operation of differentially connected relay while energising a transformer, the relay restraining coil is biased with

The single phasing relays are used for the protection of

In the case of transmission line protection, over current relay is used

To protect most of the electrical equipment handling low power, the types of relays used are

........ Relays is preferred for phase fault on short transmission line

Zero sequence current is used for relaying purpose only in the case of

Admittance relay

Where severe synchronising swing occur, the relay employed is

Interruption of large currents by relay requires

For the protection of lines against faults involving variable fault resistance, the preferred relaying scheme is a

The inverse definite mean time relays are used for over current and earth fault protection of transformer against

............. Relays are used for phase faults on long line

Relays can be designed to respond to changes in

DC shunt relays are made of

Which one of the following relay has the capability of anticipating the possible major fault in a transformer ?

Which relay is used to detect and protect internal fault in a transformer ?

Directional over current relays have two exciting coils connected across