It will take much longer time to replace all electromagnetic relays by micro processor based static relays. What is PLC? Serious over voltage is also caused by breaking of control circuit, relay contacts etc. Microprocessors, which are made of millions of semiconductors, are now more powerful than ever before. Several setting groups: Wider range of parameter adjustment: Communications built in (serial, Ethernet, teleprotection, etc.) Its economic advantage is its massive production of goods thereby lowering price. larger cable ducts). enumerated the advantages of PLC over the traditional relay logic. Moving contacts are present. The fast advance of electronic components, especially integrated circuits, over the past ten years did not lead – as was often prophesied – to a drop in the demand for relays. In Electromagnetic relays operating current flows through the coil. They have a lot of advantages over semiconductor switches, though those advantages have been eroded with the improvements of MOSFETs, IGBTs, SCRs and Triacs. Compact Size Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. 2. Induction Relay. So, No problem of Arcing No needs to replace contacts. Advantages of Numerical relays 1. Advantages of Solid-State Relays Over Electro-Mechanical Relays. One is generally called ‘‘Low Power Relays’’ or ‘‘Power Relays’’ (both terms mean the same, that is, a low-power electromagnetic relay with a swi tching current not exceeding 30 A). When this operating current increases, coil energizes the electromagnet. When this operating current increases, coil energizes the electromagnet. Static Relays Electromagnetic Relays; Power consumption: Very less 1 milliwatt: High 2 watt: Moving contacts: No moving contacts. 1: Graphical Representation Of PLC. The performance of CT under short-circuit condition is also improved. Programmable relays are best in simple applications that won’t need to be changed often. Modern electrical protection relays are mainly micro processor based, but still electromagnetic relay holds its place. Programmable Relay Advantages. Relays used for i. as interfaces between control circuits and load circuits, ii. In Electromagnetic relays operating current flows through the coil. In Electromagnetic Attraction Relays, there is a coil which energises an electromagnet.When the operating current becomes large, the magnetic field produced by an electromagnet is so high that it attracts the armature or plunger, making contact with the trip circuit contacts.These are the simplest type of relays. TABLE 2 – Advantages of numerical relays over static relays. An SSR depends on electronic devices such as SCRs and triacs to switch without contacts. Introduction Many electronic designs can take advantage of the improved performance of solid-state relays (SSRs) relative to that of electro-mechanical relays (EMRs) that perform the same circuit function. Fig. Relays are the essential component for protection & switching of a number of the control circuits & other electrical components. These are the different types of electromagnetic relays. However, static overcurrent relays offer several advantages over the electromagnetic form: ADVERTISEMENTS: 1. Internal Fault diagnosis: Power system measurements available: Distance to fault locator: Disturbance recorder: Auxiliary protection functions (broken conductor, negative sequence, etc.) 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. PLCs have a lot more functions that just use like relay contacts, though they were first made to replace relays. Installation . 9 Reasons Why PLC is used over Microcontrollers. Upvote (2) Views (38852) Followers (1) Write an Answer Register now or log in to answer. Space advantages. Such voltage spikes of small duration can damage the semiconductor components and also cause mal operation of relays. They also provide relay, timer, and counter functions in a single unit. PLC • In old days, electrical control was mostly based on relays (Contactors) (i.e. These are used as protective relays in AC systems alone and are usable with DC systems. The solid state device completes the contact function. A small PLC can be roughly the size of a house brick. Weibull distribution can also be used to determine the failure rate. Reduced design, installation and component costs. 3 Answers; Answer added by Deleted user 6 years ago . Relays contain several parts to make them work. However, the more complex SSR might just win you over when it comes to performance. To sort these issues, Programmable logic controller (PLC) was introduced. One of the advantages of electromechanical relays over solid-state switches is that relays have much lower contact resistance. A simple architecture of PLC is shown in figure below. Static relays are sensitive to voltage transients which are caused by operation of breaker and isolator in the primary circuit of CTs and PTs. While manufacturers have largely moved over to programmable logic for these tasks, relays offer a simple and cheap alternative. Electromechanical relays are a relatively old technology that use a simple mechanical design approach, whereas solid state relays are much newer and advanced—and yes, more complex. And also cause mal operation of breaker and isolator in the relay basics & different of... Triacs to switch without contacts many functions with the end goal that they open or close contacts! 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