Overcurrent Relay Characteristics: The operating time of all Overcurrent Relay Characteristics tends to become asymptotic to a definite minimum value with increase in the value of current. This is inherent…
General Equation for Electromagnetic Relay: It has already been shown that when not more than two quantities are involved, the equation for the characteristic of the relay at the threshold…
Relay Design and Construction: The Relay Design and Construction is normally divided into the following stages: Selection of the operating characteristics. Selection of proper construction. Design of the contact movement…
Induction Relay Torque Equation: In Induction Relay Torque Equation, Two magnetic fluxes Φ1 and Φ2 differing in time phase penetrate through a disc. These alternating fluxes induce emfs e1 and e2 in…
Types of Electromagnetic Relays: There are two principal Types of Electromagnetic Relays: Attracted armature type; and Induction type. (a) Attracted Armature Type: This includes plunger, hinged armature, balanced beam and…
Relay Classification in Power System Protection: There are various types of Relay Classification in Power System Protection. Normally the actuating quantity is an electrical signal, although sometimes the actuating quantity…
Important Questions of Protective Relays: 1. What is protective relay ? Explain its function in an electrical system. 2. Discuss the fundamental requirements of protective relaying. 3. Describe briefly some…
Solid State Relay Interfacing: To avoid the problems of mechanical relays, Solid State Relay Interfacing are used. In this triac is used as a switching element and isolation is provided…