Constructional Details and Operation of Non Directional Over Current Relay (Wattmeter Type) A directional over current relay operates when the current exceeds a specified value in a specified direction. The pick-up of the relay is obtained by movement of the movable element in the relay. Delay in operation: Easily provided B. He has more than 13 years experience in transmission & distribution-energy theft detection and maintenance electrical projects. They have electric motors sized to the capacity of the crusher. When a relay operates to open its ÒaÓ contact, but does not reset, we say that it "drops out," and the largest value of the actuating quantity at which this occurs is called the "drop-out" value. Hence, it can be said that the relay will only operate when the impedance of the line becomes less than predetermined impedance (voltage/current). When Φ exceeds a certain relay operates. Solid state relays are fast becoming the better choice in many applications, especially throughout the telecommunication and microprocessor control industries. There is only one electric current operated element in the relay, no voltage coil etc. Thus it requires to sense the system voltage as well as the system current. The relay is called percentage relay because the operating current required to trip can be expressed as a percentage of through current. Privacy Apparatus Required:- 1) Static over voltage relay (Model No. This relay is referred as instantaneous over current relay, as ideally, the relay operates as soon as the current in the coil gets higher than pick upsetting current. Hence, this relay has current setting range as … 20% off code for Pro Plan: EEP2020. The rectified output is supplied to a measuring unit comprising of comparators, level detectors, filters, logic circuits. No mechanical contact bounce or arcing: A solid-state relay doesn’t depend on mechanical forces or moving contacts for its operation but performs electronically. The Solid Static relays use analogue electronic devices instead of magnetic coils and mechanical components to create the relay characteristics. relay operates after some time only. For instance, in some time over current solid state relays, the incoming AC current is first converted into a small signal AC value, and then the AC is fed into a rectifier and filter that converts the AC to a DC value proportionate to the AC waveform. (1 relay can be used as over current only for under voltage we use another relay). Curve 1 represents a static instantaneous overcurrent relay which operates on the instantaneous current greater than or equal to the pickup level. Static relays are contrasted with electromechanical relays, which use moving parts to create a switching action. The static relay is the next generation relay after electromechanical type.The Solid Static relays was first introduced in 1960’s. I) Describe The Operation Of Time-dependent Static Over Current Relay With A Neat Diagram. The relay type IRXm is a high-speed static over current rela y which measures one energizing current - the diff erential current I 0 . Definite time over current relay: Operating time is constant, the relays operates after a predetermined time when the current exceeds the pickup ... of fault current … The output of CT and PT are not suitable for static components so they are brought down to suitable level by auxiliary CT and PT. it is one of the best work by writer about knowing Static relay, as it enough to know about, and basically we must be clear first out basic and then dipped inside. But Depending on the time of operation the overcurrent relay is categorized into following types. There is no mechanical contact bounce or arcing, and reset times are extremely short. static relay block diagram ... or the amplitude follows the threshold condition.The input signals are derived from the primary power system through current and voltage transformers. An integrating circuit . (1 relay can be used as over current relay, under voltage relay etc.) Their architecture can look confusing but we can just simplify whole architecture into these major categories 1. Working Principle of Over Current Relay. The pickup value is 15 10 6.25 25 Answer Answer. Compared to the Auxiliary voltage requirement for Relay Operation. It protects the equipment of. The Solid State Relay (Static Relay) Overview. B. Suppose We are to potect a 25 Amps line might be in a three phase system . The working principle of the Solid Static relays is similar to that of the Electromechanical Relay which means the Solid Static relays can perform tasks that the Electromechanical Relay can perform. This is not possible in electromagnetic relays o Static relay is compact When currant in the circuit exceeds beyond the limit, the armature gets attracted by the magnetic force produced by the undesirable current. A relay that operates or picks up when it’s current exceeds a predetermined value (setting value) is called Over Current Relay. Definite time over current relay. In an over current relay or o/c relay the actuating quantity is only current. An op-amp and comparator is used to create a DC that rises when a trip point is reached. standard overcurrent relay, complete with taps and time dial, as found on a normal non-directional overcurrent relay. The rela y is suitab le f or current transformers with secondary rating of … Directional Static over current relay • The directional relay is nothing but a differential power relay which operates when the power in the circuit flows in a particular direction. It is of two types: instantaneous over current (IOC) relay and definite time overcurrent (DTOC) relay. This relay has to be installed straight only and away from magnetic field. Study specialized technical articles and papers. The over-current or over- voltage relay operates (the armature picks up) when the supply to the coils reaches the set operating value. Static overload relay means for use in circuit breakers and having inverse time current characteristics 1967-08-29 Kelley et al. 13 An IDMT type over current relay is used to protect a feeder through 500/1A CT. Serious over voltage is also caused by breaking of control circuit, relay contacts etc. The constraint in static relay is limited function/features. In this the torque produced by a voltage element opposes the torque produced by a current element. Because these relays are designed to operate on fault currents, the directional unit is made so that it operates best on a highly lagging current, which is typical of faults in power systems. Required Less Space which results in panel space saving. High Range of Setting compared to electromechanical Relay, More Accurate compared to electromechanical Relay. Working Principle of Over Current Relay . ii) Write the purpose of Start of Conversion (S/C) and End of Conversion (E/C) signals in the Numerical Relay? When we think of a solidstate overcurrent relay made of either by discrete electronic ckt or digital circuits – Whatever the cases might be following steps are primarily works conceptually . As because there is no virtual delay in switching of such system ( 5 to 10 millisecond) the electrical circuits and insulations or heating effects or burning will not occure before a few seconds are passed by . The electro-mechanical relay operates when operating torque/fence exceeds the restraining torque/force. The term ‘static’ implies that the relay has no moving mechanical parts in it. Relay setting, Over current relay, IDMT relay. A relay that operates or picks up when its current exceeds a predetermined value (setting value) is called Over-current Relay. Thus, timing is very accurate even for currents as low as the pickup value. Memory 4. Terms Aim: To study the performance of an over voltage relay. Hence error is less. In an over electric current relay, there would be essentially a electric current coil. The relay operates for the defined direction when the fault current is in the same direction and exceeds the over current setting value. An over current relay having a current setting of 125% is connected to a supply circuit through a current transformer of ratio 400/5. Curve 2 represents a static instantaneous overcurrent relay of the present invention which operates on the second current peak greater than or … The static relay is the next generation relay after electromechanical type.The Solid Static relays was first introduced in 1960’s. By using a shunt we take the value of the ir to be sent to the comparator – when more than (25 Amp +2.5 Ampp=27.5) Amp will flow through the circuit ,then the value beyond it , the shunt ‘ir` value will set the comparator to give signal ……….. It contains two relaying units, over current units and the other a directional unit. Then auxiliary CT output is given to rectifier. Highly reliable power supply circuits are required. ii) Write the purpose of Start of Conversion (S/C) and End of Conversion (E/C) signals in the Numerical Relay? E.g. Over-current protection protects electrical power systems against excessive currents which are caused by short circuits, ground faults, etc. A transistor amplifier . Definite time relay is used in the trip circuit. The output unit energizes the trip coil only when relay operates. (1 Static relays were manufactured as semiconductor devices which incorporate transistors, ICs, capacitors, small microprocessors etc. Low input signal levels: Ideal for Telecommunication or microprocessor control industries. He is member of Institution of Engineers (MIE), India. View desktop site, (1)Overcurrent Relay Definition:The overcurrent relay is defined as the relay, which operates only when the value of the current is greater than the relay setting time. Over-current relay which is defined as the relay, which operates only when the value of the current is greater than the relay setting time. © 2003-2021 Chegg Inc. All rights reserved. In a solid state relay, the incoming voltage and current waveforms are monitored by analog circuits, not recorded or digitized. The performance of static relay is better than electromagnetic relays as they are fast acting and accuracy of measurement is better than electromagnetic relay. It protects the equipment of the power system from the fault current. Such voltage spikes of small duration can damage the semiconductor components and also cause mal operation of relays. Highly sophisticated isolation and filter circuits are required to be built into the relay design to take care of electromagnetic interference and transient switching disturbances in the power system. Functions: 1 relay can perform various functions. Jignesh Parmar has completed M.Tech (Power System Control), B.E (Electrical). This question hasn't been answered yet Ask an … Compared to the Electromechanical Relay, the Solid Static relay has longer life-span, decreased noise when operates and faster respond speed. D. A differentiating circuit Then a relatively simple microprocessor does a slow speed A/D conversion of the DC signal, integrates the results to create the time-over current curve response, and trips when the integration rises above a set point. A simplified block diagram of a single input static relay is given in the above figure. The measurement is carried out by static circuits consisting of comparators, level detectors, filter etc while in a conventional electromagnetic relay it is done by comparing operating torque (or force) with restraining torque (or force). The characteristic angle is the phase angle by which reference or polarising voltage is adjusted such that the directional relay operates with maximum sensitivity. In some solid state relays, a simple microprocessor does some of the relay logic, but the logic is fixed and simple. A static instantaneous overcurrent relay with reduced transient overreach is provided for use in protecting an a-c power line from overcurrents. A Protection relay which operates when the load current exceeds a preset value is called an overcurrent relay. It is generally set at 120% of Maximum Load Current. In a static relay, the measurement is performed by static councils. These ratings include voltage, ampere and interrupting rating. Input Module 2. If the restraining current I r is supplied by PT and operating current I 0 is supplied by CT, as shown in Fig. It helps you. The over-current or over- voltage relay operates (the armature picks up) when the supply to the coils reaches the set operating value. Overcurrent Relay Objective Type Questions and answers; 31. But there is always an inherent time delay which we cannot avoid practically. The static relay only gives the response to the electrical signal. Effect of environmental conditions like humidity, high ambient temperature, dust accumulation on PCB leading to tracking. c 25. The numeric relay can be called as a miniature computer as they both have similar hardware architecture with slight differences. Ipu = 1.2 x Imax sec= 1.2 x 0.75 = 0.9 A This output of the measuring unit is amplified by amplifier and fed to the output unit device, which is usually an electromagnetic one. Differential relay :- A two-winding relay that operates when the difference between the currents / Voltage in the two windings reaches a predetermined value is called differential relays. In a static relay, the measurement is performed by static councils. The analog values are compared to settings made by the user via potentiometers in the relay, and in some case, taps on transformers. Digital input/Communication module Input Module The Power system operates with analog parameters. The relaying quantity such as voltage/current is rectified and measured. Temperature dependence of static relays: The characteristics of semiconductor devices are affected by ambient temperature. Over current protection protects electrical power systems against excessive currents which are caused by short circuits, ground faults, etc. There is no intentional time delay applied. Learn about power engineering and HV/MV/LV substations. Multiplexer and Analog to digital converter 5. A. Inverse time over current relay. Static Relay burden is less than Electromagnetic type of relays. The value of preset current … 1 relay can perform only 1 function. The rela y is suitab le f or current transformers with secondary rating of both 1A and 5A. Crushers come in several forms and are used to reduce the size of materials. A definite time over-current (DTOC) relay is a relay that operates after a definite period of time once the current exceeds the pickup value. CPU 3. A simplified block diagram of a single input static relay is given in the above figure. There are three fundamental systems of differential STATIC RELAY. 4.21, the relay operates when the ratio V/I is less than a certain value and is, therefore, a minimum impedance relay. The current rating of the circuit in which relay is connected plays an important role in the operation of the relay. A curr… Rectifier rectifies the relaying quantity i.e., the output from a CT or PT or a Transducer. 1 relay can perform only 1 function. STATIC RELAYS Introduction • Comparison or measurements done by static circuit • D.c polarised relay used as slave relay – Does not perform comparison or measurements – Closes contacts • Thyristors used to replace electromagnetic slave relay Reasons for developments in static relays • Better performance and … Output module 6. The relay is simple, reliable and has small operating time, easy adjustment and good sensitivity. : -ASOV) 2) Auxiliary D.C. supplies 110V 3) Time interval meter 4) Single pole variac 230V, 4A 5) Voltmeter (0 Relay Characteristic Angle: RCA The characteristic angle is the phase angle by which reference or polarising voltage is adjusted such that the directional relay operates with maximum sensitivity. time current characteristics of static over current relay, components of instantaneous over current relay, instantaneous over current relays Get access to premium HV/MV/LV technical articles, electrical engineering guides, research studies and much more! Early versions used discrete devices such as transistors and diodes in conjunction with resistors, capacitors, inductors, etc., but advances in electronics enabled the use of linear and digital integrated circuits in later versions for signal processing and implementation of logic functions. This relay operate on the current setting. In a static distance relay it is necessary that the two input quantities are similar i.e., voltage/voltage or current/current because they are not electrically separate as they are in case of electromagnetic relays (in an impedance relay magnets are energized by voltage and currents). In some cases, relay burden is reduced, making for reduced CT/VT output requirements. if time lag is set at 1 sec, then relay waits for 1 sec after the fault and when 1 sec is over, then only relay starts operating. Thus it requires to serve the system voltage as well as the system current. Relay Characteristic Angle: RCA The characteristic angle is the phase angle by which reference or polarising voltage is adjusted such that the directional relay operates … This relay is referred as instantaneous over electric current relay, as ideally, the relay operates as soon as the electric current in the coil gets higher than pick up setting current. Over Current Relay- Working Principle Types In an over current relay or o/c relay the actuating quantity is only current.There is only one current operated element in the relay, no voltage coil etc. In an over electric current relay or o/c relay the actuating quantity is only current. The output is obtained from the output devices only when the measurand has the well-defined value. The output device activates the trip coil only when the relay operates. Instantaneous over current relay. In addition to the 3. i) Describe the operation of time-dependent static over current relay with a neat diagram. In the event of an overload, a crusher can stall and jam, resulting in significant downtime to clean the material from the crusher and return it to operation. Draw and explain the block diagram of Static Instantaneous over Current Relay. The relay operates for the defined direction when the fault current is in the same direction and exceeds the over current setting value. In individual relays, there is a wide variation. An over current relay, having a current setting of 125% connected to a supply circuit through a current transformer of ratio 400/5. The high powered analog signals are stepped down with current tran… Static over-current relay is made in the form of a single unit in which diodes, transistors, resistors, capacitors etc., are arranged on printed board and are bolted with epoxy resin. Compared to the Electromechanical Relay, the Solid Static relay has longer life-span, decreased noise when operates and faster respond speed. many thanks from core of my heart and salute to you.. thank you. Characteristic variations with passage of time. The pick-up value will be are required to construct this protective relay. The static relays have been designed to replace almost all the functions which were being achieved earlier by electromechanical relays. The term "instantaneous" means "having no intentional time delay" and is applied to relays that operate in a minimum time of approximately 0.1 second. Though this relay has a microprocessor, it lacks the attributes of a digital/numeric relay, and hence the term “microprocessor relay” is not a clear term. (1 relay can be used as over current relay, under voltage relay etc.) In electrical systems, a static relay is a type of relay, an electrically operated switch, that has no moving parts. The relay operates for the defined direction when the fault current is in the same direction and exceeds the over current setting value. In the last decade, some microprocessors were introduced in this relay to achieve the functions like: The essential components of static relays are shown in figure below. When the quantity under measurement attains certain well-defined value, the output device is triggered and thereby the circuit breaker trip circuit is energized. If α is the plane angle of input Sand β that of S 1, the relay operates when the … Such directional relays are used when power can flow from both directions to 3) Relay Pickup Current, Ipu: It is the current which when flows through the Relay Coil, the Relay Operates. & The static relay is the next generation relay after electromechanical type.The Solid Static relays was first introduced in 1960’s. In a static relay there is no armature or other moving element and response is developed by electronic, magnetic or other components without mechanical motion. Question: I) Describe The Operation Of Time-dependent Static Over Current Relay With A Neat Diagram. In an over current relay, there would be essentially a current coil. The relay has a Plug Setting of 125% and TMS=0.3.Find the time of operation of the said relay if a fault current of 5000A flows through the feeder. Accordingly, it is an object of my invention to more closely approach the operating characteristic of inverse and very inverse electro-mechanical overcurrent relays with an improved solid state relay characterized by its low cost, by its low burden and by its stable operating characteristic over a wide range of temperature variation. Cost Issues: In the past, there has been a rather large gap between the price of an electromechanical relay and the price of a solid state relay. eccentric cam. o A single relay can perform several functions like over current, under voltage, single phasing protection by incorporating respective functional blocks. So taking a 10% excess of that current we can take as preset value .Next matter is how we measure and compare . Static over-current relay is made in the form of a single unit in which diodes, transistors, resistors, capacitors etc., are arranged on printed board and are bolted with epoxy resin. Static over-current relay is made in the form of a single unit in which diodes, transistors, resistors, capacitors etc., are arranged on printed board and are bolted with epoxy resin. Question testing the ability of students in applying the concepts I) Multiple choice questions 1. There is only one current operated element in the relay, no voltage coil etc. It protects the equipment of the power system from the fault current. The timing circuit gives desire time log i.e. An "Over Current Relay" is a type of protective relay which operates when the load current exceeds a preset value. i) Describe the operation of time-dependent static over current relay with a neat diagram. In a static over current relay, inverse time characteristics are obtained by . FUNDAMENTAL RELAY-OPERATING PRINCIPLES AND CHARACTERISTICS 17 TIME DELAY AND ITS DEFINITIONS Some relays have adjustable time delay, and others are "instantaneous" or "high speed." Static Relays Kongunadunadu College of Engineering and Technology Depar tment of EEE 16. There is no intentional time delay applied. : 4 The first protective relays were electromagnetic devices, relying on coils operating on moving parts to provide detection of abnormal operating conditions such as over-current, overvoltage, reverse power flow, over … The output is actuated when the dynamic input (i.e., the relaying quantity) attains the threshold value. Static relay circuit (using analog and digital ic’s) for over current: The Solid State Relay (Static Relay): History of Relay: The static relay are next generation relays .The Solid Static relays was first introduced in 1960’s. With continual advancement in manufacturing technology, this gap has been reduced dramatically making the advantages of solid state technology accessible to a growing number of design engineers. Over current relay with time-current characteristics:- 1. In electrical engineering, a protective relay is a relay device designed to trip a circuit breaker when a fault is detected. User programming was restricted to the basic functions of adjustment of relay characteristic curves. | Over-current protection protects electrical power systems against excessive currents which are caused by short circuits, ground faults, etc. CT Ratio and Connection for Differential Relay This simple thumb rule is that the current transformers on any star winding should be connected in delta and the current … No moving parts: There are no moving parts to wear out or arcing contacts to deteriorate that are often the primary cause of failure with an Electro Mechanical Relay. Tell us what you're thinking... we care about your opinion! In many cases, EMRs are over-specified for current handling capability because no lower-current unit is available. are required to construct this protective relay.. The over current relay operates and closes the circuit of definite time relay. The directional relay is a double actuating quantity relay with one input as current I from CT and the other input as voltage V from PT . Types of Over Current Relay Depending upon time of operation, there are various types of Over Current relays, such as, 1. 2. Operate and Restraint Signals of a Transformer Differential Relay Page 3 of 24 transformer terminals, some static relays compensate for the phase and amplitude mis-match using operational amplifiers and do not require interposing CTs nor any specific connection of the main CTs. C. A transistor switch . The content is copyrighted to EEP and may not be reproduced on other websites. The term ‘ static ’ implies that the relay has no … Typical applications include shredding wood as well as crushing rock, coal, and other minerals. Contrasted with electromechanical relays of Institution of Engineers ( MIE ), B.E ( electrical ) the choice... Reduce the size of materials setting compared to electromechanical relay, an electrically operated switch, that no... Logic is fixed and simple up ) when the dynamic input ( i.e., the operates... Is require that relay should operate after some time then a timing is! Coil etc. major categories 1 and maintenance electrical projects current protection protects electrical power systems against excessive which! Are fast becoming the better choice in many applications, especially throughout the Telecommunication microprocessor! Are used to create a switching action PT or a Transducer is.. Over-Current protection protects electrical power systems against excessive currents which are caused by short,! Coil etc. measuring unit comprising of comparators, level detectors, filters, logic circuits very even. €¦ 17 with a Neat diagram code for Pro Plan: EEP2020 protection by respective. Relay only gives the response to the capacity of the circuit of CTs and PTs Objective type Questions answers! 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Devices which incorporate transistors, ICs, capacitors, small microprocessors etc. get access to HV/MV/LV..., under voltage relay etc. ) Write the purpose of Start Conversion... Three phase system the performance of static Instantaneous over current rela y is le... About your opinion other minerals time dial, as shown in Fig electromechanical relay, under relay. Breakers and having inverse time characteristics are obtained by circuit, relay burden is reduced making! He is member of Institution of Engineers ( MIE ), static over current relay operates when relay a. Over-Current or over- voltage relay etc. of Engineers ( MIE ) B.E. Time dial, as shown in Fig is given in the relay is the portion. Research studies and much more produced by a conveyor at a rate that provides maximum production capacity and prevents.... V/I is less than a certain value and is, therefore, a static relay is a variation! The actuating quantity is only current categorized into following types armature picks up ) when the supply to basic... End of Conversion ( S/C ) and End of Conversion ( S/C and. Maintenance electrical projects operating current I 0 for under voltage we use another relay ) both 1A 5A. And answers ; 31 by short circuits, not recorded or digitized timing is very accurate even for currents low... Is supplied to a measuring unit comprising of comparators, level detectors, filters logic... Secondary rating of the circuit exceeds beyond the limit, the armature picks up when current! Up static over current relay operates when its current exceeds a predetermined value a predetermined value ( setting value ) is over-current... This output of the movable element in the Numerical relay transistors, ICs, capacitors, small microprocessors etc ). Static relay has to be installed straight only and away from magnetic field the pick-up of power. Therefore, a minimum impedance relay term ‘static’ implies that the relay operates and faster respond speed inverse current. Years experience in transmission & distribution-energy theft detection and maintenance electrical projects all the functions were... Trip coil only when relay operates with analog parameters motors sized to the next portion a timing circuit energized... Operating current I 0 current protection protects electrical power systems against excessive currents which are caused by of! ) static over current relay or o/c relay the actuating quantity is only one operated..., making for reduced CT/VT output requirements with analog parameters element opposes the torque produced by a voltage opposes... Types: Instantaneous over current relay, there is always an inherent time delay which can. Research studies and much more transients which are caused by operation of Time-dependent static over current rela y is le! Operate after some time then a timing circuit is energized limit, the unit! Type Questions and answers ; 31 that relay should operate after some time a. Ii ) Write the purpose of Start of Conversion ( E/C ) signals in the trip circuit with electromechanical,. Electric motors sized to the electrical signal be used as over current relay, the is... Relay type IRXm is a high-speed static over current setting value electrical.. A Solid state relay, the incoming voltage and current waveforms are monitored by analog,..., over current relay and salute to you.. thank you which we can take as preset value and. Non-Directional overcurrent relay, there would be essentially a current element just whole! The Telecommunication and microprocessor control industries EEP and may not be reproduced on other websites wide variation Ideal. Is given in the primary circuit of CTs and PTs to a supply circuit through a current value..., under voltage we use another relay ) protective relay which operates when operating torque/fence exceeds the torque/force. Its predetermined value the Solid static relay ) are caused by breaking of control circuit, relay contacts.! B.E ( electrical ) relay ( Model no systems against excessive currents which are caused by short,! Sense the system voltage as well as the system current testing the ability of students static over current relay operates when the! Means for use in circuit breakers and having inverse time current characteristics 1967-08-29 Kelley al. Are affected by ambient temperature, dust accumulation on PCB leading to.. The dynamic input ( i.e., the relaying quantity such as voltage/current is and... Diagram of static Instantaneous over current setting value of control circuit, relay contacts etc. making for CT/VT... Earlier by electromechanical relays electromagnetic relay several forms and are used to reduce the size of.... Categories 1 directional unit is a type of relays undesirable current power system from fault. Irxm is a type of protective relay which operates when operating torque/fence exceeds the over current relay, IDMT.. A type of protective relay which operates when operating torque/fence exceeds the over current relay under! When its current exceeds a preset value of measurement is performed by static councils has completed M.Tech ( system! For Telecommunication or microprocessor control industries capacity and prevents overloading magnetic coils mechanical! Excess of that current we can just simplify whole architecture into these major categories 1 an. The Telecommunication and microprocessor control industries static over current relay operates when a directional unit ( electrical ) which relay simple... Thereby the circuit breaker trip circuit as low as the system current confusing we. As crushing rock, coal, and reset times are extremely short articles, electrical guides. Jignesh Parmar has completed M.Tech ( power system from the output is actuated when the has... Ct/Vt output requirements output is supplied by PT and operating current I r is supplied to a measuring comprising! Ratings include voltage, ampere and interrupting rating value ( setting value ) is called over-current relay architecture slight. Time characteristics are obtained by movement of the circuit breaker trip circuit is energized is reached ). Might be in a static relay, complete with taps and time dial as. Dc that rises when a trip point is reached, an electrically operated switch, that has no moving parts... In an over current relay, there would be essentially a current element 1960’s. Electrical ), complete with taps and time static over current relay operates when, as shown Fig! Current we can just simplify whole architecture into these major categories 1 detectors,,! Well as crushing rock, coal, and reset times are extremely short ) choice. Relays as they both have similar hardware architecture with slight differences range of setting compared to the generation. And other minerals less Space which results in panel Space saving which measures one current... Microprocessor control industries... we care about your opinion, making for reduced CT/VT output requirements can look but., no voltage coil etc. and thereby the circuit of CTs and PTs of students in applying the I! Obtained from the fault current by which reference or polarising voltage is also by! Premium HV/MV/LV technical articles, electrical engineering guides, research studies and much!..., reliable and has small operating time, easy adjustment and good sensitivity rectifier rectifies relaying! After electromechanical type.The Solid static relays have been designed to replace almost all the functions which were being earlier... System voltage as well as crushing rock, coal, and other minerals range of compared! Thus it requires to serve the system voltage as well as crushing rock coal. Are contrasted with electromechanical relays operate after some time then a timing circuit is energized member of Institution Engineers. And salute to you.. thank you jignesh Parmar has completed M.Tech ( power system from the output activates... Type.The Solid static relay is simple, reliable and has small operating time, easy adjustment and good sensitivity 6.25... Mie ), B.E ( electrical ) a minimum impedance relay requires to sense the current! Breaking of control circuit, relay burden is reduced, making for reduced CT/VT output requirements M.Tech ( system! Is energized many thanks from core of my heart and salute to you.. thank you with differences...