TQM Tools Interview Questions and Answers: 1. What is benchmark? Ans. Benchmarking is a systematic search for best practices, innovative ideas and highly effective operating procedure. 2. What are the…
Directional Static Overcurrent Relay: For obvious reasons of obtaining selectivity overcurrent relays are made directional. Directional static overcurrent relay senses direction of power flow by means of phase angle between…
What is Summation Transformer? Summation devices are employed to compare the relaying quantities derived from the currents in the three phases of the primary circuit. The effectiveness of the comparison…
Thermal Relay Construction and Working Principle: Thermal Relay can operate on the principle of thermal effect of electric current. It consists of bimetallic strips which are used in small sizes…
Electromagnetic Induction Relay - Structure and Working Principle: Electromagnetic induction relay operate on the principle of induction motor and are widely used for protective relaying purposes involving a.c. quantities. They…
Factors to be Considered in Selection of Fuse: In order to ensure that the fuses will correctly and reliably protect any given section or element of an electrical circuit, selection…
Instrument Transformers - Definition, Types and Errors: AC type protective relays are actuated by current and voltage supplied by current and potential (or voltage) transformers, known as instrument transformers. The…
Overlapping Zones of Protection: Overlapping Zones of Protection - In order to provide selectivity to the system it is usual practice to divide the entire system into several protection zones.…