Thomas Stevic is controls engineer at Zed Industries, a thermoforming and plastic packaging machine builder in Vandalia, Ohio. An equivalent terminology chart is used as an aid in the comparison of EMRs and SSRs. It uses a flag system for the indication purpose whether the relay has been activated or not. Electromechanical and static relays have fixed wiring and the setting is manual. You can change your ad preferences anytime. Unlike Electromechanical relays the following tasks can be performed by Numerical relays. Electro Mechanical (Start of Century). An electromechanical relay consists of three terminals namely common (COM), normally closed (NC) and normally opened (NO) contacts. A relay uses an electromagnet to pull a contact against the force of a retaining spring. Contacts What Is Numerical Relay. Here we explain WHY & HOW Numerical Relays are better than ElectroMechanical Relays. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Digital input/Communication module Input Module The Power system operates with analog parameters. Michael P. Collins is president of MPC Management, a consulting company in Portland, Oregon. Basic hardware is shared between multiple functions, the cost of individual protection functions can be reduced significantly. Types of Relays The relay may be defined as an electrical device interposed between the main circuit and the circuit breaker in such a manner that any abnormality in the circuit acts on the relay, which in turn if the fault is dangerous then it causes the circuit breaker to isolate and so to … The microprocessor based relay furnishes easy interface with digital communication equipment. Traditional electromechanical and static protection relays offers single-function and single characteristics. Loss of voltage feature helps block the relay in case of momentary/permanent loss of voltage. Electromagnetic Relay. To understand this concept easily, it is better to know about settings of the Electromechanical Relays. Instead, it consists of semiconductors and optocouplers within. Numeric relays, on the other hand, are programmable relays where the characteristics and behavior can be programmed. (for EM relay 100 mile ohm,other relay are 10 ohm) Motor Protection Features Available: Thermal protection; Unbalance protection; Undercurrent protection The relays control the electric circuit by opening or closing the contacts of that circuit. Numerical Relay Evolution Cont.. Spring A Relay is an electromechanical device that can be used to make or break an electrical connection. One relay can be used in many ways. They are more user friendly and offer multi-functional protection schemes. Looks like you’ve clipped this slide to already. In utility and industrial electric power transmission and distribution systems, a numerical relay is a computer-based system with software-based protection algorithms for the detection of electrical faults. In 1990, the acceptance of numerical technology by the customer and the experiences of the user helped in developing the second generation numerical relays. Digital protection can be physically smaller, and almost always requires less panel wiring than equivalent functions implemented using analog technology. One of the major advantages of numerical relays is that it can store pre-fault as well as post-fault dataso that it can be us… Delay in operation: Easily provided I have noticed that still in many plants, people don't know how to download settings, Fault Record and configurations from Numerical Relay. Now customize the name of a clipboard to store your clips. It will take much longer time to replace all electromagnetic relays by micro processor based static relays. The microprocessor based relays have minimum burden on the instrument transformers. Email your Inquiry at BDM@systemprotection.in. If you continue browsing the site, you agree to the use of cookies on this website. The second main purpose for installing relays is to amplify and isolate the smaller voltage control circuits from the large voltages and currents driving larg… (1 relay can be used as over current relay, under voltage relay etc.) Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. Numerical Relay Is Also A Digital System, Which Is Concisely Communicating With Substation Automation. Helps analysis of faults by recording details of: Electromechanical relay do not have the ability to detect whether the normal condition has been attained once it is activated thus auto resetting is not possible and it has to be done by the operating personnel, while in numerical relay auto resetting is possible. A significant improvement in the relay reliability is obtained because the use of fewer components results in less interconnections and reduced component failures. Relays are electrical parts that are used when a low-power signal is needed in order to control a circuit, or when a number of circuits need to be controlled by one signal. Being based on entirely different switching principles, t he direct comparison between semiconductor relays and electromechanical relays turns out to be delicate. Sensing Coil Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. One relay can be used in many ways. the numerical relay having compact size compared to electro mechanical relays, the electro mechanical relays having lot of components, including flag systems. See our Privacy Policy and User Agreement for details. (many literature say both are same-Digital/Numerical Relays – T.S.M. The size of the numerical relays is much less as compared to that of electromechanical and static relays due to the multi-functionality approach of the former. Modern electrical protection relays are mainly micro processor based, but still electromagnetic relay holds its place. The electromechanical and static relays are hard wired Memory 4. Time Adjustment: Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Nevertheless, we attempt to elaborate the advantages of the respective relay types in the following:. Greater sensitivity and high pickup ratio. Numerical relay consists of many functions in one relay thus replace many traditional relays with one. Fibre optical communication with substation LAN. Both terms are used to refer to the same thing. What is Relay? Rao) 2.why In comparison table relay resistance are different unit? Tension controlled The first function of the relay is to provide logical sequences of circuitry which allows various combinations of input devices to drive output machinery following very specific logical steps. A relay is an electromechanical device having electrical, magnetic and mechanical components. Select Accept cookies to consent to this use or Manage preferences to make your cookie choices. An electrical relay is an electromagnetically operated electrical switch - an electromechanical switch. Availability of fault data and disturbance record. For example, we have the following protections in numerical relays in-built into one relay. and mechanical relay required more electrical wiring but numerical relay required very less wiring. Clipping is a handy way to collect important slides you want to go back to later. This relay has to be installed straight only and away from magnetic field. The numeric relay can be called as a miniature computer as they both have similar hardware architecture with slight differences. Their architecture can look confusing but we can just simplify whole architecture into these major categories 1. With static relays, tripping time of ½ cycle or even less can be obtained. Figure 6. but numerical relay is having LCD to indicate the alarm and relay activation. It is possible to provide better matching of protection characteristics since these characteristics are stored in the memory of the microprocessor. It is a fact that the numerical relays investment cost is more than the Electromechanical one if we limit the application to protection. The high powered analog signals are stepped down with current tran… The relay hardware consists of standard modules resulting in ease of service. While numerical relay is in compact size and use indication on LCD for relay activation. It consists of a flexible moving mechanical part which can be controlled electronically through an electromagnet, basically, a relay is just like a mechanical switch but you can control it with an electronic signal instead of manually turning it on or off. Due to these factors, numerical relays are referred to as present generation relays. An Electromechanical relay provides switching using electromagnetic devices. whenever the rely is activate the flag also activated. A variety of protection functions can be accomplished with suitable modifications in the software only either with the same hardware or with slight modifications in the hardware. It uses a flag system … Few of the differences between conventional (electromechanical) and solid state (digital / numerical) relays can be highlighted as below: An electromagnetic relay is a switch that is turned on and off by a magnetic field. Danny Weiss is senior product manager at Newark element 14. Many of you have Numerical Relays in your plant for protecting different Electrical equipment's like Generator, Transformers, Transmission lines and Motors.But, many times we don’t use Numerical Relay to its full or atleast 80% of its capability. This force pulls the armature and closes the relay contacts: SSRs do not have electromagnet or any moving contacts in it. Some applications are best served by … a power switching solution that can be used to allocate power without manually opening and closing the switch Unlike electromagnetic relays, these do not contain any moving parts and thereby serving all the benefits of static relays as well. Advantages of Numerical Relays: Numerical relay consists of many functions in one relay thus replace many traditional relays with one. For more information, see our Cookie Policy. 1. An electrically operated switch to be exact. Relay manufacturers use a common code (form letter) to simplify the identification of relays. NUMERICAL RELAY In 1985, the first protection devices based on microprocessors were employed. Electro Mechanical Relay • Electro-Mechanical Relays are non-communicable • These relays cannot be used for Sub Station Automation & SCADA system Numerical Relay • Numerical Relays are Communicable with all Standard Protocols • Numerical Relays can be used for Sub Station Automation & SCADA system effectively Why do we recommend Numerical Relay? A machine control relay is an electromechanical relay that includes several sets (usually two to eight) of NO and NC replaceable contacts (typically rated at 10 A to 20 A) that are activated by a coil. Electromechanical Relays. It is very easy to provide electrical isolation between the coil that creates the magnetic field and the switch contacts. The numerical relay is one of electrical base of the software protection against to detect the natural & unnatural fault in the electrical machinery. PSM and TMS settings that is Plug Setting Multiplier and Time Multiplier Setting are the settings of a relay used to specify its tripping limits. With advancement in technology, ElectroMechanical Relays are replaced by Numerical relays. Test datas of electromechanical relay III. Input Module 2. Output module 6. These relays are usually microprocessor based and are programmable according to the needs of the user. A relatively small current is used to create a magnetic field in a coil within a magnetic core and this is used to operate a switch that can control a much larger current. The first numerical relays were released in 1985. If we clear the concept for these relays first then understanding the Numerical Relay settings becomes easy. (1 relay can be used as over current only for under voltage we use another relay). Consists of no mechanical moving parts hence accurate operation. Disc Numerical Relay These facilities are satisfied only by numerical technology. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. The first forms of ladder schematics were built from these circuits of sequential relay logic, and later these ladder schematics were adopted for digital logic controllers. Global digital protective relay market size, Modeling of a digital protective relay in a RT Digital Simulator, No public clipboards found for this slide. 9. There are other relay technologies available to users, with different characteristics to reed relays; for example, electromechanical relays (EMRs), solid state relays and MEMS (microelectromechanical systems) switches. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. If you continue browsing the site, you agree to the use of cookies on this website. A solid state relay depends on SCRs and triacs to switch without contacts. Range of operation of electromechanical relays is narrow as compared to numerical relay. Kurt Wadowick is I/O and safety produ… Users can configure relay according to their system requirement. We and third parties such as our customers, partners, and service providers use cookies and similar technologies ("cookies") to provide and secure our Services, to understand and improve their performance, and to serve relevant ads (including job ads) on and off LinkedIn. A big difference between conventional electromechanical and static relays is how the relays are wired. Such relays are also termed as microprocessor type protective relays. Electromechanical relays Solid-state relays; In these relays, electromechanical force is generated by the relay coil on the application of voltage. No maintenance is needed like electromechanical relays. You can change your cookie choices and withdraw your consent in your settings at any time. Functions: 1 relay can perform various functions. CPU 3. An electromechanical relay, put simply, is a switch. Case Study - How we saved a Process Plant…, Case Study - How we solved an Earth-fault…, Case Study - Importance of Relay Selection…, By combining several functions in one case, numerical relays also save capital cost and maintenance cost over electromechanical relays, Separate connection is not required, zero sequence voltages and currents can be derived inside the processor. Machine Control Relays. Stephen Kirk is project manager at Industrial Automation Group, a system integrator in Modesto, California. Multiplexer and Analog to digital converter 5. 1.what is difference between numerical relay & digital relay? See our User Agreement and Privacy Policy. Core Numerical Relays are the advanced version of relays by using microprocessor and programming software these relays work. 1 relay can perform only 1 function. Electromagnetic relays are those relays which are operated by electromagnetic action. 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