This current is known as inrush current. Prone to restricts. Top Most Power System Protection Interview Questions, Q:What are the functions of protective relays. As the operating time of primary relay is less than that of the backup relay, it will operate first. Why Does The Adjacent Zones Of Protection Overlap? (b) The stability of the system is affected by the faults in the bus zone. The interview seemed pretty superficial and none of the questions were very hard. It is usually used in oil immersion transformers with a rating over 750KVA. Representation of various power system components in a single line is Q: What are the advantages of oil as arc quenching medium? Is the second line of defence , which operates if the primary protection fails to activate within a definite time delay. It is one of the important factors taken into consideration for selecting a current transformer. Using a short circuit generator as the source. RLDC, SLDC, NLDC 6. in this bus the magnitude of voltage and phase angle are specified. Therefore, the IDMT relay will not be of much help. Q: What is meant by electro negativity of SF6 gas? A. The protection is organized to provide a ring of security around each and every element of power system. Electron in the outer orbit is known as valence. equipments. Fuse is a low current interrupting device. Q: Mention any 2 applications of differential relays. What is different between resistance grounding system and resistance earthing system? Name the latest computer processors? Compensation testing Explain differential protection? Where are the lighting arrestors placed in distribution lines? Bucholz relay is used to give an alarm in case of incipient( slow-developing) faults in the transformer and to connect the transformer from the supply in the event of severe internal faults. How can you relate power engineering with electrical engineering? • Closing of one capacitor bank against another. Electrical Interview Questions & Answers visit www.eeekenya.com Page | 1 ... Power factor should be high in order to get smooth operation of the system. The farthest point from the relay which is still inside the zone of protection is called reach point and the distance between relay and reach point is called reach. 13. No gravity effect on operation of static relays. Top 100 Switchgear and Protection Interview Questions. Q: State the various types of unsymmetrical faults. Even CT’s of proper turn-ratio are used, the differential current may flow through the relay under normal condition. It has good dielectric strength and excellent arc quenching property. Near distribution transformers and outgoing feeders of 11kv and incoming feeder of 33kv and near power transformers in sub-stations. This is the basic Power BI Interview Questions asked in an interview. • The air blast circuit breakers are very sensitive to variations in the rate of rise of restriking voltage Q:What are the demerits of using oil as an arc quenching medium? Static relay can think , programmable operation is possible with static relay What is the Power plant or Power Station? Fast operation, auto re-closing possible, easy discrimination of simultaneous faults . Whenever a short-circuit occurs, the current … Bias coil will solve this. To know the answer in detail, click on the link given in the answer. Large number of circuits, different current levels for different circuits for external faults. Voltage is stepped up before transmission due to … Q. Q: What are over and under current relays? 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