Methods of testing these elements, settings criterion, diagnosing misoperations will all be in your bag of tools to perform your job with confidence. Contactors and contactor relays for railway contactors and. This comparison summarize characteristics of all protection relay types described in previously published technical articles. Most utilities have a wide variety of test plans and practices. Oo courses hosted by relay manufacturers specific to their relays. Sealin unit target target target z 1 z 2 z 3 t 2 t 3 sealin unit tc breaker aux. Jun 18, 2017 relay protection testingfor ge, sel, nari, sifang, siemens, abb etc. These are sometimes called relays or solenoid, motor contactor, battery relay, ev relay, heavy equipment relay, pv relay and special purpose contactor.
The main difference between the contactor and relay is that, contactor is a high power device while relay is a low power device. Contactor vs relay difference between relay and contactor duration. Understanding and testing the abb red670 distanceline. This page contains technical data sheet, documents library and links to offering related to this product. By design and construction they ensure potential isolation between the actuating. Abb advanced feeder protection system ref 550 instruction booklet 7. Pdf the relay protection coordination for photovoltaic. Relay elements in step distance schemes use positivesequence impedance in step distance schemes three relay elements are needed for detecting multiphase or singlephasetoground faults k z. Oo testset manufacturer, or automated test software, training focused on how to get their solution to test. Transformer relay protection program life of a transformer. The relay will now use 30% of this itotto derive its actual restraint current, i. Protective relaying philosophy and design guidelines pjm.
Directional overcurrent and directional power relays. A relay is normally used in appliances below 5kw, while a contactor is preferred when the appliance is heavier. Pdf this paper presents a procedure and computation of relay protection coordination for a pv power plant connected to the distribution network. Relays, programmers, electronics boards and components. Industrial relay modules and solidstate relays overview easy handling and safe connections weidmullers relay bases are remarkable for their secure connection systems and their ease of use during wiring and installation. There are various types of control relays including machine tool relay, industrial relay and general purpose relay. The safety cover of magnetic contactor and thermal overload relay is optional. Abstractperforming tests on individual relays is a common practice for relay engineers and technicians. The control relay is one of the oldest type of relay and perhaps the best known.
They can be used as standalone manual starters or to protect each branch circuit of a group motor installation. Contactors and relays are two closely related terms leading to confusions and misinterpretations most of the times. Implementation of a distance relay to protect transmission line l1 3. Epic sealing technology is used f or gigavac part series mx16, automatic disconnect. Contactors and relays is a course designed to familiarize participants with the operation and use of magnetic contactors and relays. Abstractwhen two or more lines are running parallel to each other, mutual impedances between the lines modify the voltage and current profile measured in the protective relays. Request document 252oct9501r697 enclosed iec starters dline starters and integral selfprotected starters are available. In general dc contacts have larger contact areas so that they can survive more damage. The contactor relay contacts themselves constitute a considerable safety feature. Also, tools for the system programming and supervision are.
Take away a sound understanding of all related protective elements such as differential, voltshertz, through fault, etc. Features, benefits and functions freedom nema adjustable bimetallic. Backup relay x y load l2 load l1 t1 s bus over current backup relay differential relay. The electronic circuit provides the power to turn the relay on, which in turn switches a larger voltage source needed to turn on a contactor.
V5t248 product overview freedom series starters and contactors feature a compact, spacesaving design, using stateoftheart technology and the latest in high strength, impact and temperature resistant insulating materials. Dc protections ac protections apparatus protective relays common features of the protection philosophy, the protective functions and the fault clearing actions are given. Contact of a relay can be used to connect or disconnect the coils of a contactor. Current splits inside the relay, supplying power to both the control and load circuits. Sometimes a special screw unitized screw and spring washer is used in the coupling section of the electromagnetic contactor and thermal overload relay in an. After completing this course, participants should be able to describe the operating principles of magnetic contactors and relays, and explain how both types of devices are used in electrical systems. Both of them are electrically operated switches used for control and switching of loads.
Difference between contactor and relay compare the. Disclaimer the data, examples and diagrams in this manual are included solely for the concept or product description and are not to be deemed as a statement of guaranteed properties. Contactors are typically built for and used in 3phase applications where a relay is more commonly used in single phase applications. In addition, you can configure the relays as dry contact relays or as 24 vdc output relays. The main difference between contactors and relays is the loads that they are meant to handle. Note minimum conduct current of auxiliary contactor is dc 17v 5ma. The transformer can then be disconnected from the system. All dil contactor relays have doublebreak contacts. Volume 5power control products ca033001enjanuary 2017.
As we can see, the fault occurred on 80% of the line ab as seen by relay a. Pluggable crossconnection and the extraquick push in connection help you to further reduce wiring times. This document gives an overview of the hvdc protection system. Fsrrm24 remote relay module installation sheet description the fsrrm24 provides five form c relays that you can configure as common relays, zone relays, or as programmable relays to use with fseries fire alarm control panels. Relays and contactors use a variety of technologies to switch signals and power connections. The three distance measuring elements z 1,z 2 and z. Relay trip signal from the distance relay 21 to the circuit breaker to protect the transmission line l1 in case of fault rest of the power system figure 4.
A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Ieee guide for protective relay applications to transmission. Because of this, relays are often used as a middleman between the electronic circuit and the contactor. Mutual impedance in parallel lines protective relaying and fault location considerations fernando calero, schweitzer engineering laboratories, inc. Overload relay motor damage 12 awg wire damage thermal withstand limit contactor breaking current contactor withstand 30i e 2 crossover point i c 5. Electrically, we have transistors and integrated circuits. Generator protection reg650 ansi application manual.
White paper on different types of relays the relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. Alternating current ac and direct current dc contactors are found in many industrial motors, including many automobiles. Episode 28 the difference between contactors and relays electromagnetic switches duration. To turn things on and off, we need devices that are switchable by the application of a current or voltage. Difference between contactor and relay since a contactor is required for a higher load, a relay is always cheaper than a contactor. These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current. Telemecanique integral selfprotected starters combine. The different contactors accomplish the same thing, but they do it in different ways, starting with how they are constructed. Control relays are available in numerous configurations. Current carry vs time contactors, high voltage relays. They are used in large numbers for the indirect control of motors, valves, clutches and heating equipment. Understanding and testing the abb red670 distanceline differential relay figure.
Topics include the selection of communication systems, redundancy, autoreclosing, ground overcurrent protection, line length and source impedance ratio. In addition to the simplicity which they offer in project engineering, panel building. Contactors and relays 5 contactor relays contactor relays contactor relays are often used in control and regulating functions. Pdf easy method for testing transformer differential relays. Pdf files add kmtronic web lan internet relays to your. This guide focuses on the general approach and specific procedures for testing protective relaying systems that include multiple interacting relay components, auxiliary devices, and power apparatus. By design and construction they ensure potential isolation between the actuating circuit and the operating circuit, in the deenergized state, between the contact input and output. Protective relaying principles and applications 4th edition. Get access to premium hvmvlv technical articles, electrical engineering guides, research.
Other relay variations include three and five pin relays. Substation automation and protection 7036 snowdrift road. Difference between contactor and relay difference between. Faults instrument transformers correlation to drawings other.
Protective relaying philosophy and design guidelines. Mutual impedance in parallel lines protective relaying and. Choosing between a relay and a contactor isnt really difficult. Transformer relay protection program monday, february 11 thursday, february 14, 2019. If the contactor coil is deenergized and the contactor does not drop out, the. Commissioning of protective relay systems karl zimmerman, schweitzer engineering laboratories, inc. Current carry vs time with 85 c terminal temperature rise 500 mcm 400 mcm. In dc circuits the arc can be maintained for longer.
In ac circuits the arc drawn as contacts open is intrinsically selfextinguishing at the zero crossing. Nfz contactor relays withstand short voltage dips and voltage sags semi f470706 compliance between 24. Contactors and contactor relays for railway applications advanced but simple the afb contactors and nfb contactor relays can be installed in any environment including passenger or driver cabins, for main or urban line trains, underground trains or trams circulating frequently in tunnels or underground passages. The basic principle of operation of the contactor and the relay are the same. Generally, a relay has several opening and closing contacts. Oo engineering books written for design engineers, not relay testers. Some of the more common variations are mentioned below. L starters with fuse protection nf c or din fuses, type am, contactor and thermal overload relay. The cmd also monitors the functioning of the internal relay using an additional. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. A directional power relay can be used to limit power flow in a circuit.
Distancerelay protection testingfor transmission line. The relay is usually used in the electrical control circuit, its used to extend the contact capacity of a micro or small relay, so as to drive larger load. Since some relays are frequencysensitive, each of the relays operating characteristics vs. Feeder protection, or more exactly protection for overhead lines and cables, is the most commonly used type of protection.