Instantaneous Overcurrent Relays: If the relay operates instantly without any intentional time delay, this characteristic can generally be satisfied by a relay of the non-polarized attracted armature type. This relay…
Methods of Discrimination in Power System Protection: Methods of Discrimination in Power System Protection are basically of two types: those which discriminate as to the location of fault, and those…
Important Questions of Switchgear: 1. What do you understand by switchgear ? 2. Discuss the various types of switches. 3. What is the difference between (i) a switch and circuit…
High Voltage Test on Circuit Breaker and Isolators: High Voltage Test on Circuit Breaker and Isolators is covered, giving common characteristics for both. While these characteristics are directly relevant to…
Circuit Breaker Ratings: A Circuit Breaker Ratings may be called upon to operate under all conditions. However, major duties are imposed on the Circuit Breaker Ratings when there is a…
Sequence Impedances and Networks of Synchronous Machine: Sequence Impedances and Networks of Synchronous Machine - Figure 10.11 depicts an unloaded synchronous machine (generator or motor) grounded through a reactor (impedance…
Selection of Circuit Breaker: There are two types of Selection of Circuit Breaker ratings which require the computation of SC current are: (i) rated momentary current and (ii) rated symmetrical…
Short Circuit of a Synchronous Machine on No Load: Short Circuit of a Synchronous Machine on No Load - Under steady state short circuit conditions, the armature reaction of a…