Instantaneous Over-current Relay 2. Multiple Choice Question (MCQ) of Protective Relays page-4; Multiple Choice Question (MCQ) of Protective Relays page-3; Multiple Choice Question (MCQ) of Protective Relays page-2; Multiple Choice Question (MCQ) of Protective Relays page-1; Multiple Choice Question (MCQ) of Fuse; Multiple Choice Question (MCQ) of Circuit Breaker page-3 A relay must get an adequate chance to protect the zone under its primary protection. What is the committed information rate (CIR)? DC relays are employed with a freewheeling diode to de-energize the coil, and the AC relays use laminated cores to prevent eddy current losses. Browse from thousands of Electrical questions and answers (Q&A). See a list of common communication skills interview questions. A. What is the Power plant or Power Station? c. Tripping circuit. Become a part of our community of millions and ask any question that you do not find in our Electrical Q&A library. The relay has two settings. Q. Behavioral Interview Questions. It refers to the current or voltage which is used to activate the relay into operation. A. Series Faults: Series faults are nothing but a break in the path of current. We tracked down the 10 most-asked interview questions by analysing our Interview Builder tool that employers and recruiters use. Some of the reasons are faster protection, simpler coordination, simpler application, permanent settings without the need for readjustment, less effect of the amount of generation and fault levels, fault current magnitude, permits the high line loading. Normal, Alert, Emergency, In extremis and Restorative. Answer : By preparing answers for these common interview questions, you can develop compelling talking points to make a great impression during your next job interview. Why distance protection is preferred as primary protection compared to overcurrent protection for transmission lines? It is observed in practice that most of the open conductor faults sooner or later develop into some or the other short-circuit fault. A. The instantaneous type attraction armature can be made a definite time lag or inverse time lag by using an oil dashpot, an air escapement chamber a clockwork mechanism or by placing a fuse in parallel with it. a. Where Impedance relay, Reactance relay, and Mho relays are employed? Thus, the pick-up value should be less than the smallest fault current. Thus fuses are used for only once but breakers can used by multiple number of times. Name the different kinds of over current relays. What is protective relay? Types: 1. The Impedance relay is suitable for the phase faults relaying for the lines of moderate lengths Reactance type relays are employed for the ground faults while Mho type of relays is best suited for the long transmission lines and particularly where synchronizing power surge may occur. b. (adsbygoogle = window.adsbygoogle || []).push({}); A. Refer to the diagram below to answer Question 5 to Question 8 Q5. Biased differential relay is preferred because its operation is not affected by the trouble arising out of the difference in the CTs ratios for high values of external short circuit currents. Firstly, it steps down the current to such a level that it can be easily handled by the relay current coil. DLCIs have local significance. Air Break Circuit Breaker 2. A. The current transformer has two jobs to do. Inverse Time Over-current Relay. Oil Circuit Breaker 3. What Are The Bandwidth Specifications Of Frame Relay? It is inverse in the sense, the tripping time will decrease as the magnitude of fault current increase. Or it is observed in practice that most of the relay into operation be sensitive enough to interview questions on relays to fault. 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