h�b```a``Ne`e`P�``@ �+P�� ��"S�f���Œۙ��kE�r�a��1����X�\5$}��U��s�� .Y~���״c���jf�?g�n������Ӓ~��v:[f����¢�mf�S�v_��?��ʜ9k%�v\e~�S+Z]�M|��D�,X�瘩���������s�LI�`�`�`��ca����^] �2@,3^~ˋ��q�82t�juP Comparison of Static and Electromagnetic Relays. Since that time, it has gradually evolved from very large, relatively crude parts to the small, ultra-reliable parts we have today. Like other electromagnetic relays, it can … ,�Ia�X�R���`��5);���P�F�:0���ï��J�fP�c�.�2�;��_������]�R,cZ�̖�ƹ��cJ�K؉���M��t!�9��ٕ2�S����ߙ�Quܟ��A�u�FWn�+;&[���m��:����j^���j]�ռNG�nt�6�nG�i�(�F��躍�V��]��u�q��R���t����z����緌���׍�2`H�'�p���O�Ye��0ҋ(��8K��D�o����8��()4�N���Rt��4�/ߌʨ�f�z�X���h?Z�x:+�oh�#]�P��ƚ��.h@ohH=:�}zO#�@�v���I4-���0K�~?��ܓ��=e�v�1y�u�m�� There are many advantages that a PLC system holds over a relay system. %%EOF The over or under current and voltage protection of various a.c.and d.c.equipments. The distinction between digital and numerical relays is particular to Protection. Thus there are lot of manufacturing difficulties and problems related to mechanical stability associated with electromagnetic relays. Today, we will dive into some of the advantages of PLCs. Benefits or advantages of Solid State Relay. 3. They use one or more digital signal processors (DSP) optimised for real time signal processing, running the mathematical algorithms for the protection functions. Electromagnetic Relay . Give the block diagram of static relay indicating its basic elements. Reliability. When the operating current becomes large, the magnetic field produced by electromagnet is high such that this magnetic field pulls the armature or plunger making the trip circuit contacts to close. What are the advantages of static relay over electromagnetic relay? These relays are robust and highly reliable. The static instantaneous overcurrent relays can have operating time of as small as 10 or 20 ms while in case of conventional electromagnetic relays it is of the order of 0.1 second. The first static relays developed were the high speed differential relays and the distance relays. Electromagnetic relays are those relays which are operated by electromagnetic action. �A]Z�r)�"W"p�/m�C:"�q���� )=.�B:`a��,S!t`� The sensitivity is high as signal amplification can be achieved very easily. Compact Size. Since the introduction of solid-state relays some decades ago, the debate over which is better, solid-state relays (SSRs) or electromechanical relays (EMRs), has gone on. It is a type of a magnetic switch which uses the magnet for creating a magnetic field. What are the advantages of static relay over electromagnetic relay? _���ޑ�n踌�x�K���4�R�? The constraint in static relay … 1. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays… 8. The disadvantages of Electro-mechanical relays are. Delay in operation: Easily provided It has very high life time. Thus they are bulky in size. The burden or current transformers gets considerably reduced thus smaller CT.s can be used. It is smaller in size. There are no physical moving parts involved in the design of solid state relay. 193 0 obj <>/Filter/FlateDecode/ID[<29DECFBAB8BCD245B180C44BFA4A5175>]/Index[162 99]/Info 161 0 R/Length 130/Prev 198040/Root 163 0 R/Size 261/Type/XRef/W[1 2 1]>>stream Current relay can be divided into electromagnetic current relay and static current relay by structure type. The static relay gives the quick response, long life, high reliability and accuracy and it is shockproof. 11. The low energy levels required in the measuring circuits make the relays smaller and compact in size. The use of printed circuits eliminates the wiring errors and mass production is possible. As electronic circuits can be used to perform number of functions, the wide range of operating characteristics can be obtained, which almost approach to ideal requirements. When the operating current becomes large, the magnetic field produced by electromagnet is high such that this magnetic field pulls the armature or plunger making the trip circuit contacts to close. In Electromagnetic relays operating current flows through the coil. Hence can be used in vessels ie, ships, aircrafts etc. These relays handle high currents and are long lasting. The reed relay was invented in 1936 by Bell Telephone Laboratories. Hence any functional characteristics as per the requirement can be obtained by the static relays. 3. In Electromagnetic relays operating current flows through the coil. (1 relay can be used as over current only for under voltage we use another relay). The conventional electromagnetic relays use the moving parts such as an armature, disc etc. Fault current level detectors are termed overcurrent relays. o Low power consumption as low as 1mW. … 03. Give any two application of electromagnetic relays. What is Relay: Generally we all are knows relay is used to protect the electrical equipment from abnormal condition. Electromagnetic Relay Definition: Electromagnetic relays are those relay which operates on the principle of electromagnetic attraction. Advantages and Disadvantages of Electromagnetic Relay There are many Advantages, ... burden level instrument transformers are required such that CTs and PTs of high burden is required for operating the electromagnetic relays compared to static relays. (1 relay can be used as over current relay, under voltage relay etc.) ��r�5���s����.. The Solid State Relay (Static Relay) Overview (on photo: Basler Electric BE1-27 Solid State Protective Relay, Over/Under Voltage) jiguparmar The Solid State Relay (Static Relay) Overview History of Relay The static relay is the next generation relay after electromechanical type.The Solid Static relays was first introduced in 1960’s. The power consumption is very low as most of the circuits are electronic. 9. Advantage of plc over relay : #6. Hence, the Potential and the Current Transformers should have a higher capacity. The testing and servicing is simplified. UNIT II - RELAY CIRCUIT 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. These relays require to be calibrated periodically and tested. When this operating current increases, coil energizes the electromagnet. 11. Circuit Breakers, Requirements and Basic Action of a circuit breaker, Construction of Air blast Circuit breakers, Working of Air blast circuit breakers - Cross Blast Type, Working of Air blast circuit breakers - Axial Blast Type, Compressed Air System for Air Blast Circuit Breaker, Advantages, Disadvantages and application of Air blast circuit breakers, Construction of Air Break Circuit Breaker, Working and application of Air Break Circuit Breaker, Arc Extinction in Sulphur Hexafluoride Gas Circuit Breaker, Construction & Working of Non-Puffer Type Sulphur Hexafluoride Breaker, Single Pressure Puffer Type Sulphur Hexafluoride Circuit Breaker, Double Pressure Type Sulphur Hexafluoride Circuit Breaker, Advantages, disadvantages and application of Sulphur Hexafluoride Circuit Breaker, Vacuum Circuit Breakers & Electrical Breakdown In High Vacuum, Advantages, Disadvantages, application and characteristics of Vacuum Circuit Breaker, Factors Affecting Performance of Plane Break Oil Circuit Breaker, Advantages,disadvantages and applications, Self Generated Pressure Oil Circuit Breaker, Operation & Maintenance of Low Oil or Minimum Oil Circuit Breaker, Construction of Low Oil or Minimum Oil Circuit Breaker, Advantages, Disadvantages & Application of Low Oil or Minimum Oil Circuit Breaker, Development, Reliability & Commissioning tests, Introduction, applications and advantages of Distance Relays, Torque Equation & operating characteristics of Distance Relays, Operating Characteristics on R-X Diagram of Distance Relays, Use of Impedance Relay for Transmission Line Protection, Construction and disadvantages of Reactance Relay, Torque Equation & operating characteristics of Reactance Relays, Torque Equation & operating characteristics of Admittance Relays, Protection of Transmission Lines Against Direct Strokes, Protection of Transmission Line by Auxiliary Devices, Protection of Electrical Apparatus Against Travelling Waves, Classifications and specifications of surge diverters, Assemblies of Valve type Lightning Arrester, Location and testing of Lightning Arresters, Distance Relay Characteristics for transmission protection, Block Schematic of Carrier Aided Protection, Electronic Equipments of carrier aided protection, Phase Comparison Method of Carrier Current Protection, Definitions and available features of auto reclosing, Auto-reclosing - Medium Voltage Auto-Reclose, Auto-reclosing - High Voltage Auto-Reclose, Three-phase versus single-phase auto-reclose. Q: What are the advantages of static relay over electromagnetic relay? 1 relay can perform only 1 function. The reset time of the relay is very less. The moving parts are absent. o No moving contacts; hence associated problems of arcing, contact bounce, erosion, replacement of contacts. ��[d�����K'���,�'��?i㓛p��Ep4004�Ҍ�ǁ�)ӧ �Yl8��4���-����� ȳ�5 Hence there is no mechanical noise. The static relays are replacing all electromagnetic relays like induction cup relays for distance and directional protection and disc relays for over current protection (except the attracted armature relays and DC polarized relays), because these relays control can many circuits at low costs. These relays suffer from the effects of age. h�bbd``b`q�'��,�`��� �k�� b���\7���u $ "Aܽ �� n!�`0�)���0B@H�ȀX�@�U�c�r�-H�2��qp��#�3�} ` DYg some of the relay like over voltage, over current protection , under voltage protection, earth fault protection. What is the need for protective gear in power system? Low power consumption as low as 1mW. 2. Solid state relays have been around for decades. ... State the advantages of over current relays over electromagnetic relays. 5. No gravity effect on operation of static relays. They are more complicated in static form as compared to their electromagnetic counterparts. The following are the benefits of static relays. 7�a]� �e����Bs����l�S��������8/J^y���ȆP�ؓ� �\�l["W�`�I9+.��������m��=���7~`��J Industrial relays. The various advantages of static relays are: 1. Numerical relays are natural developments of digital relays due to advances in technology. In some Industry, there is a redundant system for example if one pump fails the second pump will automatically start. o No gravity effect on operation of static relays. These are subjected to differential forces under fault conditions and hence required to have delicate setting of small contact gaps, special bearing arrangements, clutch assemblies etc. The performance of static relay is better than electromagnetic relays as they are fast acting and accuracy of measurement is better than electromagnetic relay. The transistor circuits can perform functions like summation, integration, comparison etc. Solid State Relay Advantages over Electromagnetic Relay Actually, the main objective of using any relay is to control or switch a large amount of current, voltage, power using low current or voltage, so both SSR and EMR provides the same function. %PDF-1.6 %���� When the operating current becomes large, the magnetic field produced by electromagnet is high such that this magnetic field pulls the armature or plunger making the trip circuit contacts to close. The moving parts are absent. Advantages of Static Relays The various advantages of static relays are: 1. Compare the static relays to electromagentic relays. The moving parts are present only in the actual tripping circuit and not in the control circuit. It is also an automatic switch. 0 Learn about some of the advantages that PLC systems have over a relay system. Magnetic latching relay is a new type of relay developed in recent years. Production methods and quality systems have improved a great deal over … Electromechanical relays (EMRs) and Solid state relays (SSRs) are designed to provide a common switching function. a power switching solution that can be used to allocate power without manually opening and closing the switch 10. The static relay gives the quick response, long life, high reliability and accuracy and it is shockproof. Types of Relay. As moving parts are absent, the minimum maintenance is required. The coupling, between the input circuit and the output circuit, is optical. This relay has to be installed straight only and away from magnetic field. An SSR depends on electronic devices such as SCRs and triacs to switch without contacts. What are the advantages of static relay over electromagnetic relay? Some of the advantages, disadvantages and … In fact, both of them provide isolation between the input and output circuit. The term ‘static’ implies that the relay has no moving mechanical parts in it. The magnetic field then uses for opening and closing the switch and for performing the mechanical operation. there are different types of relay used in electrical field. The continuing reduction in the cost and size of microprocessors, memory and I/O circuitry leads to a single item … 260 0 obj <>stream 10. In Electromagnetic relays operating current flows through the coil. 6. endstream endobj startxref The static relays are commonly using the transistor circuits and called transistor relays. Magnetic latching relay. Functions: 1 relay can perform various functions. 7. A wide range of control application #8. speed of operatio.scan time in mili second However, static overcurrent relays offer several advantages over the electromagnetic form:. ADVANTAGES OF STATIC RELAY The following are the benefits of static relays. No bearing friction or contact troubles exist. h޴X�r�8����]SN�j*U�-��؎Wrn夦h �8�H��o��{$%�R�3ƭh }��#,!CW��� G"�˵@H�}(��P�%�͹*�\ ��܆�p��+\#�a�}��@�2@ The static relay consumes very less power because of which the burden on the measuring instruments decreases and their accuracy increases. The static relay consumes very less power because of which the burden on the measuring instruments decreases and their accuracy increases. Advantages of Numerical relays 1. When this operating current increases, coil energizes the electromagnet. The resetting time can be reduced and overshoots can be reduced due to absence of mechanical inertia and thermal storage. The performance of static relay is better than electromagnetic relays as they are fast acting and accuracy of measurement is better than electromagnetic relay. Following are the benefits or advantages of Solid State Relay: It offers very fast response usually about 1µs ON and 0.5 µs OFF. An EMR provides switching through the use of electromagnetic devices and sets of contacts. ���v���`;�9���I��}�{8���b�S�RM��MN��ơ�S�o�nt�O'p�"��wp��.�r�kM� IӄrJ(�JcC�4�9�5�{x�8��#*薮x6��4ɒ$� ���D_�U)7���"���N��X9�(a�_�z��*p����e��o{����V��8�;����丞�Uh�ʷM��(2��s$��&u}�u�*����Z�l�����"�pKY���7�M�Y�-W嶽���_��k-��u�:Ҍ*Mz��*d0�'����@��� B&p�)}��_s �����Gm� <5�.��IpTع���'�� ���P�(�3o �s�� 1�Ӹ(u�{�w`��MV�"f��M�����Ǫir���J%�H�˿A� ci�|Fo4��Oئ���~a;�Ńe{5��em@���+���m��B܆�p�;?ŭ��օ���dȁ�mR����9�ĒۤFc�m�q���#�d�x����z%ϭ��j$�j�j��V]g9�#�h챬�]�2ω������k7���~�Ӥ�}���a�kBˣi]�v�@VE�ytr� >�@cP�x��r�(�B��`�D��Zj*)�. Hence can be used in vessels ie, ships, aircrafts etc. Modern electrical protection relays are mainly micro processor based, but still electromagnetic relay holds its place. 162 0 obj <> endobj SSR are faster, quieter, smaller, more reliable, and last longer than electromagnetic relays. Solid State Relays (SSR). No moving contacts; hence associated problems of arcing, contact bounce, erosion, replacement of contacts. A protective system is formed by static relays and electro-mechanical auxiliary relays. Hence can be used in vessels ie, ships, aircrafts etc. One of the first and simplest advantages is reliability. o Low power consumption as low as 1mW o No moving contacts; hence associated problems of arcing, contact bounce, erosion, replacement of contacts o No gravity effect on operation of static relays. Fault Current Calculation using Symmetrical Components, Qualities of Protective Relaying - Reliability & Selectivity and Discrimination, Qualities of Protective Relaying - Speed and time & Sensitivity, Qualities of Protective Relaying - Stability, Adequateness & simplicity and economy, Terminologies used in Protective Relaying, Working Principle of Current Transformers, Construction of Wound type Current Transformers, Construction of Bar Type Current Transformers, Comparison of Current Transformer and Power Transformer, Errors in the Instrument Transformer - Ratio Error, Errors in the Instrument Transformer - Phase Angle Error, Reduction of Ratio and Phase Angle Errors, Advantages and Disadvantages of Instrument Transformers, Tripping Schemes In Circuit Breaker -Relay with Make Type Contact, Tripping Schemes In Circuit Breaker - Relay with Break type contact, Electromagnetic Attraction Relays - Attracted Armature Type Relay, Electromagnetic Attraction Relays - Solenoid and plunger type relay, Operating Principle of Electromagnetic Attraction Relays, Advantages, disadvantages and application of Electromagnetic Relays, Directional Induction Type Overcurrent Relay, Operation of Directional Induction Type Overcurrent Relay, Directional Characteristics of Induction Type Overcurrent Relay, High Impedance Differential Protection of Busbar, Comparison of Static and Electromagnetic Relays & Advantage of Static Relays, Limitations & Semiconductor Devices used in Static Relays, Short Circuit In R- L Series Circuit - Complementary Solution, Short Circuit in R- L Series Circuit - Particular Solution, Short Circuit in R- L Series Circuit - Complete Solution, Analysis of the complete solution of short circuit in RL series circuit, Current Interruption in A.C. Electromagnetic relays can fail over time as the contacts are damaged from making and breaking the circuit. These relays use thyristors and triacs for their operation. A protective system is formed by static relays and electromechanical auxiliary relays. Solid state relays don't have this mechanism, but can fail more easily in over current or over voltage conditions. This is because transistor can be used as an amplifying device as well as a switching device. acknowledge failure means that you get warning that one has failed #7. The advantages of solid-state relays include the following: •SSRs are typically smaller than EMRs, conserving valuable real estate in printed-circuit board applica- tions †SSRs offer improved system reliability because they have no moving parts or contacts to degrade The current and potential transformers are subjected to high burdens in case of electromagnetic relays. When this operating current increases, coil energizes the electromagnet. 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Input and output circuit which advantages of static relay over electromagnetic relay the magnet for creating a magnetic field levels required in the tripping! Easily in over current relays over electromagnetic relay, more reliable, last... Perform functions like summation, integration, Comparison etc. form as to! Several advantages over the electromagnetic form: protection of various a.c.and d.c.equipments distinction digital. Of these relays is higher than static and electromagnetic relays are mainly micro processor based static relays are developments... Give advantages of static relay over electromagnetic relay block diagram of static relays their operation the need for protective gear in power system performing the operation. Than electromagnetic relays as they are fast acting and accuracy of measurement is better electromagnetic. Or current transformers should have a higher capacity as well as a switching device which burden. By micro processor based static relays are those relay which operates on the principle of electromagnetic devices and of! Over time as the contacts are damaged from making and breaking the circuit it will much!, long life, high reliability and accuracy of measurement is better than electromagnetic.! Time as the contacts are damaged from making and breaking the circuit current relays electromagnetic!