See a list of common communication skills interview questions. d. All of these. Actuating quantity is change in current in case of over current relay Differential Relays must have the following features: Relay settings mean the actual value of the energizing or characteristic quantity at which the relay is designed to operate under given conditions. Generator Protection Interview Questions; Protection Relays Interview Questions; Neutral Grounding in Power System; Answer: Basic fundamental elements of the relay are: Sensing element: It is the measuring element measures the actuating quantity. It is an electrical device designed to initiate the isolation of a part of the electrical installation, or to operate an alarm signal, in the event of abnormal condition or a fault. The time setting decides the operating time of the relay while the plug setting decides the current required for the relay to pick up. Where Does Negative Phase Sequence Relay Is Employed? A CT whose primary is in series with the line in which current is to be measured. 0. A. What Is The Operation Principle Of Differential Relay? 78% of relaying is still electromechanical. To detect the fault and initiate the operation of the circuit breaker to isolate the defective element from the rest of the system, thereby protecting the system from damages consequent to the fault. a. What is the operation principle of the differential relay? Post on: April 24, 2016 . What does the first part consist of? It has two contacts namely fixed contact & moving contact. No real technical question but they asked me to submit a piece of code that I had written. An over-current (OC) relay has a single input in the form of ac current. What Are The Bandwidth Specifications Of Frame Relay? What is protective relay? Under normal conditions the moving contact comes in contact with fixed contact thereby forming the closed contact for the flow of current. Thus, the pick-up value should be less than the smallest fault current. Where does Negative phase sequence relay is employed? Answer : Plug Setting Multiplier and is defined as the ratio of fault current in the relay coil to the pick-up value. The output of the relay is a normally-open contact, which changes over to closed state when the relay trips. The output of the relay is a normally-open contact, which changes over to closed state when the relay trips. Windows Server Interview Questions: Windows Server is a series of different server operating systems that have been developed by the Microsoft Corporation. Dear Readers, Welcome to Switchgear Protection Interview Questions and Answers have been designed specially to get you acquainted with the nature of questions you may encounter during your Job interview for the subject of Switchgear Protection.These Switchgear Protection Questions are very important for campus placement test and … The team was very welcoming and friendly. Secondary of the CT and the operating coil. A. What is the committed information rate (CIR)? Difference between them, Electrical & Instrumentation QC Interview Questions, Start Stop of one Motor from the same Push button PLC program, Remote Seal Transmitters Ranging Calculation, Difference between AC and DC Solenoid Valves, Ability to operate with low values of voltage, There should be no voltage and current creep. In the above figure, the relay circuit is divided into three parts. We'll assume you're ok with this, but you can opt-out if you wish. A. Define operating time of … Oil Circuit Breaker 3. Answer: 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 are best suited for the long transmission lines and particularly where synchronizing power surge may occur What is percentage differential relay? A. What is the Power plant or Power Station? Name the different kinds of over current relays. The circuit breaker is an electrically operated switch, which is capable of safely making, as well as breaking, short-circuit currents. current transformer interview questions and answers is very important for electrical graduates. If SF6 (Sulpher Hexa Fluoride) gas is used as arc quenching medium in a Circuit breaker, it is termed as SF6 CB. 300+ TOP Protection Relay Engineer Interview Questions [UPDATED] Question 1. Question 2. Inverse Time Over-current Relay. At the same time, the relay should be sensitive enough to respond to the smallest fault. These are the time setting and the plug setting. An over-current (OC) relay has a single input in the form of ac current. I don't leave many remarks, but i did some searching and wound up here "Interview Questions on Transformer Protection". Air Blast Circuit Breaker 5. By preparing answers for these common interview questions, you can develop compelling talking points to make a great impression during your next job interview. Here are some very important current transformer interview questions with proper answers which are mostly asked with Electrical Graduates in every industrial interview as … In an IDMT (inverse definite minimum time) relay, the operating principle is based on the idea that with the more severe a fault is, the faster it should be cleared to avoid damage to the apparatus. Become a part of our community of millions and ask any question that you do not find in our Electrical Q&A library. Many questions about teamwork will be behavioral interview questions. Encapsulation types of Frame Relay : Cisco and IETF (Internet Engineering Task Force) 7. In IDMT relay its operating is inversely proportional and also a characteristic of minimum time after which this relay operates. 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