Reliability. The low energy levels required in the measuring circuits make the relays smaller and compact in size. The reset time of the relay is very less. ��r�5���s����.. h�bbd``b`q�'��,�`��� �k�� b���\7���u $ "Aܽ �� n!�`0�)���0B@H�ȀX�@�U�c�r�-H�2��qp��#�3�} ` DYg A wide range of control application #8. speed of operatio.scan time in mili second 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. Advantages of Static Relays The various advantages of static relays are: 1. 2. 0 Like other electromagnetic relays, it can … Types of Relay. 11. 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 disadvantages of Electro-mechanical relays are. When this operating current increases, coil energizes the electromagnet. 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 moving parts are present only in the actual tripping circuit and not in the control circuit. 7. 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. These relays are robust and highly reliable. ADVANTAGES OF STATIC RELAY The following are the benefits of static relays. Compare the static relays to electromagentic relays. 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. An SSR depends on electronic devices such as SCRs and triacs to switch without contacts. What is Relay: Generally we all are knows relay is used to protect the electrical equipment from abnormal condition. Advantages of Numerical relays 1. In Electromagnetic relays operating current flows through the coil. Magnetic latching relay. %PDF-1.6 %���� Hence, the Potential and the Current Transformers should have a higher capacity. 03. 11. Since that time, it has gradually evolved from very large, relatively crude parts to the small, ultra-reliable parts we have today. It is a type of a magnetic switch which uses the magnet for creating a magnetic field. The burden or current transformers gets considerably reduced thus smaller CT.s can be used. 162 0 obj <> endobj Following are the benefits or advantages of Solid State Relay: It offers very fast response usually about 1µs ON and 0.5 µs OFF. endstream endobj startxref Electromagnetic relays are those relays which are operated by electromagnetic action. 10. An EMR provides switching through the use of electromagnetic devices and sets of contacts. Delay in operation: Easily provided The transistor circuits can perform functions like summation, integration, comparison etc. 8. ��[d�����K'���,�'��?i㓛p��Ep4004�Ҍ�ǁ�)ӧ �Yl8��4���-����� ȳ�5 (1 relay can be used as over current relay, under voltage relay etc.) 1. Electromagnetic relays can fail over time as the contacts are damaged from making and breaking the circuit. SSR are faster, quieter, smaller, more reliable, and last longer than electromagnetic relays. Solid State Relays (SSR). o No moving contacts; hence associated problems of arcing, contact bounce, erosion, replacement of contacts. endstream endobj 163 0 obj <> endobj 164 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text/ImageC/ImageI]/Properties<>/XObject<>>>/Rotate 0/Type/Page>> endobj 165 0 obj <>stream The coupling, between the input circuit and the output circuit, is optical. Fault current level detectors are termed overcurrent relays. Solid state relays don't have this mechanism, but can fail more easily in over current or over voltage conditions. Modern electrical protection relays are mainly micro processor based, but still electromagnetic relay holds its place. Some of the advantages, disadvantages and … Hence can be used in vessels ie, ships, aircrafts etc. Hence can be used in vessels ie, ships, aircrafts etc. What is the need for protective gear in power system? Learn about some of the advantages that PLC systems have over a relay system. The testing and servicing is simplified. The moving parts are absent. The power consumption is very low as most of the circuits are electronic. The resetting time can be reduced and overshoots can be reduced due to absence of mechanical inertia and thermal storage. Compact Size. Numerical relays are natural developments of digital relays due to advances in technology. Comparison of Static and Electromagnetic Relays. When this operating current increases, coil energizes the electromagnet. 9. These relays suffer from the effects of age. The first static relays developed were the high speed differential relays and the distance relays. The term ‘static’ implies that the relay has no moving mechanical parts in it. o No gravity effect on operation of static relays. o Low power consumption as low as 1mW. Advantage of plc over relay : #6. What are the advantages of static relay over electromagnetic relay? 3. Electromagnetic Relay Definition: Electromagnetic relays are those relay which operates on the principle of electromagnetic attraction. ... State the advantages of over current relays over electromagnetic relays. %%EOF 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. As moving parts are absent, the minimum maintenance is required. Electromechanical relays (EMRs) and Solid state relays (SSRs) are designed to provide a common switching function. Low power consumption as low as 1mW. In some Industry, there is a redundant system for example if one pump fails the second pump will automatically start. 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 Hence can be used in vessels ie, ships, aircrafts etc. 1 relay can perform only 1 function. The static relays are commonly using the transistor circuits and called transistor relays. Today, we will dive into some of the advantages of PLCs. 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. 260 0 obj <>stream The various advantages of static relays are: 1. 10. They are more complicated in static form as compared to their electromagnetic counterparts. In Electromagnetic relays operating current flows through the coil. 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 reed relay was invented in 1936 by Bell Telephone Laboratories. No bearing friction or contact troubles exist. some of the relay like over voltage, over current protection , under voltage protection, earth fault protection. 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. A protective system is formed by static relays and electro-mechanical auxiliary relays. 3. Give any two application of electromagnetic relays. The distinction between digital and numerical relays is particular to Protection. 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 VA burden of these relays is higher than static and numerical relays. there are different types of relay used in electrical field. Industrial relays. a power switching solution that can be used to allocate power without manually opening and closing the switch These relays use thyristors and triacs for their operation. However, static overcurrent relays offer several advantages over the electromagnetic form:. Benefits or advantages of Solid State Relay. Functions: 1 relay can perform various functions. This is because transistor can be used as an amplifying device as well as a switching device. 6. What are the advantages of static relay over electromagnetic relay? 5. Give the block diagram of static relay indicating its basic elements. Q: What are the advantages of static relay over electromagnetic relay? The moving parts are absent. The static relay consumes very less power because of which the burden on the measuring instruments decreases and their accuracy increases. ,�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�� �A]Z�r)�"W"p�/m�C:"�q���� )=.�B:`a��,S!t`� What are the advantages of static relay over electromagnetic relay? The following are the benefits of static relays. Solid state relays have been around for decades. 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. The sensitivity is high as signal amplification can be achieved very easily. The performance of static relay is better than electromagnetic relays as they are fast acting and accuracy of measurement is better than electromagnetic relay. Hence there is no mechanical noise. The continuing reduction in the cost and size of microprocessors, memory and I/O circuitry leads to a single item … 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. It is smaller in size. They use one or more digital signal processors (DSP) optimised for real time signal processing, running the mathematical algorithms for the protection functions. No moving contacts; hence associated problems of arcing, contact bounce, erosion, replacement of contacts. A protective system is formed by static relays and electromechanical auxiliary relays. Hence any functional characteristics as per the requirement can be obtained by the static relays. In Electromagnetic relays operating current flows through the coil. 7�a]� �e����Bs����l�S��������8/J^y���ȆP�ؓ� �\�l["W�`�I9+.��������m��=���7~`��J This relay has to be installed straight only and away from magnetic field. There are many advantages that a PLC system holds over a relay system. The conventional electromagnetic relays use the moving parts such as an armature, disc etc. The constraint in static relay … 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 over or under current and voltage protection of various a.c.and d.c.equipments. It has very high life time. 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. Electromagnetic Relay . The use of printed circuits eliminates the wiring errors and mass production is possible. 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 It is also an automatic switch. In fact, both of them provide isolation between the input and output circuit. These relays require to be calibrated periodically and tested. ���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*)�. It will take much longer time to be replaced the all electromagnetic relays by micro processor based static relays. 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 These relays handle high currents and are long lasting. 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. There are no physical moving parts involved in the design of solid state relay. No gravity effect on operation of static relays. The magnetic field then uses for opening and closing the switch and for performing the mechanical operation. Production methods and quality systems have improved a great deal over … Thus there are lot of manufacturing difficulties and problems related to mechanical stability associated with electromagnetic relays. (1 relay can be used as over current only for under voltage we use another relay). The static relay consumes very less power because of which the burden on the measuring instruments decreases and their accuracy increases. The static relay gives the quick response, long life, high reliability and accuracy and it is shockproof. Magnetic latching relay is a new type of relay developed in recent years. Thus they are bulky in size. … The current and potential transformers are subjected to high burdens in case of electromagnetic relays. One of the first and simplest advantages is reliability. When this operating current increases, coil energizes the electromagnet. acknowledge failure means that you get warning that one has failed #7. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays… 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. 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. _���ޑ�n踌�x�K���4�R�? h޴X�r�8����]SN�j*U�-��؎Wrn夦h �8�H��o��{$%�R�3ƭh }��#,!CW��� G"�˵@H�}(��P�%�͹*�\ ��܆�p��+\#�a�}��@�2@