Unlike Electromechanical relays the following tasks can be performed by Numerical relays. Disc It is possible to provide better matching of protection characteristics since these characteristics are stored in the memory of the microprocessor. The microprocessor based relay furnishes easy interface with digital communication equipment. Electromagnetic Relay. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. Output module 6. Core 1 relay can perform only 1 function. (many literature say both are same-Digital/Numerical Relays – T.S.M. Traditional electromechanical and static protection relays offers single-function and single characteristics. One relay can be used in many ways. Sensing Coil 9. The first numerical relays were released in 1985. 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… (for EM relay 100 mile ohm,other relay are 10 ohm) Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. NUMERICAL RELAY In 1985, the first protection devices based on microprocessors were employed. 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. but numerical relay is having LCD to indicate the alarm and relay activation. You can change your ad preferences anytime. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. Clipping is a handy way to collect important slides you want to go back to later. An equivalent terminology chart is used as an aid in the comparison of EMRs and SSRs. Instead, it consists of semiconductors and optocouplers within. These relays are usually microprocessor based and are programmable according to the needs of the user. Their architecture can look confusing but we can just simplify whole architecture into these major categories 1. 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. 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. A relay is an electromechanical device having electrical, magnetic and mechanical components. To understand this concept easily, it is better to know about settings of the Electromechanical Relays. Delay in operation: Easily provided Digital protection can be physically smaller, and almost always requires less panel wiring than equivalent functions implemented using analog technology. Time Adjustment: 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. 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. (1 relay can be used as over current only for under voltage we use another relay). CPU 3. Spring With advancement in technology, ElectroMechanical Relays are replaced by Numerical relays. It is a fact that the numerical relays investment cost is more than the Electromechanical one if we limit the application to protection. For example, we have the following protections in numerical relays in-built into one relay. Rao) 2.why In comparison table relay resistance are different unit? A significant improvement in the relay reliability is obtained because the use of fewer components results in less interconnections and reduced component failures. The numerical relay is one of electrical base of the software protection against to detect the natural & unnatural fault in the electrical machinery. Some applications are best served by … Looks like you’ve clipped this slide to already. Digital input/Communication module Input Module The Power system operates with analog parameters. If you continue browsing the site, you agree to the use of cookies on this website. Such relays are also termed as microprocessor type protective relays. Here we explain WHY & HOW Numerical Relays are better than ElectroMechanical Relays. Nevertheless, we attempt to elaborate the advantages of the respective relay types in the following:. The microprocessor based relays have minimum burden on the instrument transformers. 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. Email your Inquiry at BDM@systemprotection.in. 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 … whenever the rely is activate the flag also activated. Tension controlled A relay uses an electromagnet to pull a contact against the force of a retaining spring. We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. What is Relay? 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? Numerical Relay Evolution Cont.. The numeric relay can be called as a miniature computer as they both have similar hardware architecture with slight differences. 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. 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 second main purpose for installing relays is to amplify and isolate the smaller voltage control circuits from the large voltages and currents driving larg… Danny Weiss is senior product manager at Newark element 14. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. An electromechanical relay consists of three terminals namely common (COM), normally closed (NC) and normally opened (NO) contacts. and mechanical relay required more electrical wiring but numerical relay required very less wiring. What Is Numerical Relay. In 1990, the acceptance of numerical technology by the customer and the experiences of the user helped in developing the second generation numerical relays. 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. An electrically operated switch to be exact. Loss of voltage feature helps block the relay in case of momentary/permanent loss of voltage. Numerical Relays are the advanced version of relays by using microprocessor and programming software these relays work. An electrical relay is an electromagnetically operated electrical switch - an electromechanical switch. Electromechanical relays Solid-state relays; In these relays, electromechanical force is generated by the relay coil on the application of voltage. Both terms are used to refer to the same thing. Stephen Kirk is project manager at Industrial Automation Group, a system integrator in Modesto, California. the numerical relay having compact size compared to electro mechanical relays, the electro mechanical relays having lot of components, including flag systems. The relays control the electric circuit by opening or closing the contacts of that circuit. See our User Agreement and Privacy Policy. Numerical Relay Is Also A Digital System, Which Is Concisely Communicating With Substation Automation. Machine Control Relays. Input Module 2. Contacts Kurt Wadowick is I/O and safety produ… 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. Motor Protection Features Available: Thermal protection; Unbalance protection; Undercurrent protection The electromechanical and static relays are hard wired Due to these factors, numerical relays are referred to as present generation relays. 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. Unlike electromagnetic relays, these do not contain any moving parts and thereby serving all the benefits of static relays as well. Numeric relays, on the other hand, are programmable relays where the characteristics and behavior can be programmed. Michael P. Collins is president of MPC Management, a consulting company in Portland, Oregon. An electromechanical relay, put simply, is a switch. It is very easy to provide electrical isolation between the coil that creates the magnetic field and the switch contacts. The relay hardware consists of standard modules resulting in ease of service. Thomas Stevic is controls engineer at Zed Industries, a thermoforming and plastic packaging machine builder in Vandalia, Ohio. Functions: 1 relay can perform various functions. See our Privacy Policy and User Agreement for details. No maintenance is needed like electromechanical relays. a power switching solution that can be used to allocate power without manually opening and closing the switch Numerical Relay These facilities are satisfied only by numerical technology. Consists of no mechanical moving parts hence accurate operation. With static relays, tripping time of ½ cycle or even less can be obtained. 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. A big difference between conventional electromechanical and static relays is how the relays are wired. Electromechanical Relay makes use of mechanical comparison devices, which cause the main reason for the bulky size of relays. (1 relay can be used as over current relay, under voltage relay etc.) Electromechanical Relays. Multiplexer and Analog to digital converter 5. An Electromechanical relay provides switching using electromagnetic devices. Advantages of Numerical Relays: Numerical relay consists of many functions in one relay thus replace many traditional relays with one. Electromagnetic relays are those relays which are operated by electromagnetic action. 1. Electromechanical and static relays have fixed wiring and the setting is manual. Figure 6. Range of operation of electromechanical relays is narrow as compared to numerical relay. Electro Mechanical (Start of Century). For more information, see our Cookie Policy. Test datas of electromechanical relay III. Greater sensitivity and high pickup ratio. The high powered analog signals are stepped down with current tran… 1.what is difference between numerical relay & digital relay? Being based on entirely different switching principles, t he direct comparison between semiconductor relays and electromechanical relays turns out to be delicate. They are more user friendly and offer multi-functional protection schemes. 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. While numerical relay is in compact size and use indication on LCD for relay activation. A Relay is an electromechanical device that can be used to make or break an electrical connection. This force pulls the armature and closes the relay contacts: SSRs do not have electromagnet or any moving contacts in it. Global digital protective relay market size, Modeling of a digital protective relay in a RT Digital Simulator, No public clipboards found for this slide. 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. Select Accept cookies to consent to this use or Manage preferences to make your cookie choices. This relay has to be installed straight only and away from magnetic field. 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. It uses a flag system for the indication purpose whether the relay has been activated or not. 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. I have noticed that still in many plants, people don't know how to download settings, Fault Record and configurations from Numerical Relay. If we clear the concept for these relays first then understanding the Numerical Relay settings becomes easy. Fibre optical communication with substation LAN. 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. It uses a flag system … Memory 4. Numerical relay consists of many functions in one relay thus replace many traditional relays with one. Modern electrical protection relays are mainly micro processor based, but still electromagnetic relay holds its place. Relay manufacturers use a common code (form letter) to simplify the identification of relays. Basic hardware is shared between multiple functions, the cost of individual protection functions can be reduced significantly. One relay can be used in many ways. Availability of fault data and disturbance record. A solid state relay depends on SCRs and triacs to switch without contacts. If you continue browsing the site, you agree to the use of cookies on this website. You can change your cookie choices and withdraw your consent in your settings at any time.