Learn vocabulary, terms, and more with flashcards, games, and other study tools. Contactor to switch relatively large output and currents. Unlike generalpurpose relays, contactors are designed to be directly connected to highcurrent load devices. Contactor vs relay electrical engineering stack exchange.
As plc is designed to be operated by plant engineers and maintenance personnel with limited knowledge of computers, it is designed to be programmed using relay ladder logic. Relays are classified into several types based on their functionality and application they are implemented for. Contactors are rated by designed load current per contact pole, maximum fault withstand current, duty cycle, design life expectancy, voltage, and coil voltage. Difference between older d2 lc1d contactors and newer lc1d. They both are commonly used in industrial and commercial applications, and. Relays, contactors, solenoids and for more information pdus. As for the difference between compact ns and masterpact ntnw, please find below a quick glimpse on the differences between compact ns and masterpact nt. Selecting a solid state relay or a solid state contactor for startstop control of an ac motor. Contactors contactors are very similar to relays in that they are electromechanical devices. These classifications include electromagnetic, solid state, high voltage, thermal relays, and so on. Difference between contactor and relay difference between. Contactors typically have multiple contacts, and those contacts are usually but not always normallyopen, so that power to the load is shut off when the coil is deenergized. The relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. This p roduces a retarding effect on motion of the rotor in either di rection.
In particular, large electrical gear as generators, motors and. Hence contactors are used in the switching of heavy loads and power circuits whereas relays are used in the switching of. Ssrs, however, consist of electronic parts with no mechanical contacts. The main difference between contactors and relays is the loads that they are meant to handle. The only difference is that relays are usually used for low voltage applications while contactors are used for higher voltage application. Generally, relays are smaller than contactors, just as ponds are generally smaller than lakes. While power relays are called contactors, control relays are simply called relays. Dec 04, 2018 relays and contactors are electrically controlled switching devices.
The motor statrter is made up of a contactor with an overload relay attached physically and electrically to it. Load capacity contactors are used in control circuits with both low and high ampere capacity that is between 15a to 12500a. Contactors are used for devices that pass more than 15 amps or loads of more than 3kw. Air products and controls multivoltage relay module. Electrical contactors and relays hvac parts online. Relay a device by means of which contacts in one circuit are operated by a change in conditions in the same circuit or in one or more associated circuits contactor a device for repeatedly establishing and interrupting an electric circuit under normal conditions. Introduction to automation system sariati page 8 1. Mini series contactors and overload relays contactors 2 contactors reversing 2 accessories 3 technical data 4 lighting circuit switching 6 overload relay 7 technical data 7 dimensions 8 freedom series contactors and overload relays contactors 10. What is the difference between solidstate relays ssrs and contact relays. Browse our resource section and find the most useful tools and documents for all our products. Simplified guide to understanding shortcircuit current rating.
A device by which contacts in one circuit are operated by a change in conditions in the same circuit or in one or more associated circuits. Ssrs are not very different in operation from contact relays electromagnetic relays. The newer contactors have coils designed for 5060hz and are signified by the 7 at the end of the part. Contactors and starters with a broad portfolio that includes everything from phase, voltage and current monitoring relays to motor protection breakers, eaton offers the protection your system needs against equipment failure and danger caused by voltage faults, current conditions or excessive load requirements. Mar 25, 2015 this feature is not available right now. What is the difference between relay and contactor. Understanding relays page 2 autoshop, all rights reserved. Ssrs solid state relays use semiconductors for nocontact operation. A general purpose motor control contactor may be suitable for heavy starting duty on large motors. In addition to the nema contactor applications, it also can be used with other types of. Distant control of ac relays, contactors and starters bulletin no. Contactors and protection relays schneider electric. The only difference between them is their power rating.
Breaking capacities of masterpact in general are higher than those of compact ns as illustrated in the attached catalogue extracts refer to masterpact specs. Difference between contactor and relay since a contactor is required for a higher load, a relay is always cheaper than a contactor. Contactors electromechanical relays electronics textbook. Unlike relays, contactors are designed to make and break higher powered circuits without being damaged.
It can be directly coupled to the contactors or remotely mounted. To complement the contactors, thermal overloads are offered for each frame size, available in several setting ranges. Overload relays solid state esp200, class 48, 958 and 958l. Difference between ssr and contact relay faq india omron ia. Main difference between contactor and starter electrical. Contactors and relays contactors dil, overload relays z eaton wiring manual 0611 510 5 5 rated operating current ie a ac3 at 400 v max.
The newer contactors automatically come with 1 no and 1 nc auxiliary contact. Power rating of contactors are more than the relays. What is the main difference between a contactor and a magnetc motor started. Contactors can be obtained with coils designed for use on higher voltages than most relays. Differences between relays and contactors rsp supply. Relays tend to be of lower capacity and are usually designed for both normally closed and normally open applications. Relay operation all relays operate using the same basic principle. These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current. Difference between contactors and relays electrical classroom.
Our extensive product portfolio and services and support capabilities are designed to improve your processes through every stage of your manufacturing cycle from design and installation through operation and maintenance. It is difficult to differentiate between plcs, bios, operating system and application program. Relays are used in a wide variety of applications like electric power systems, home. It has at least a single pair of three phase input and output contacts. Therefore, this document is intended to describe about a few basic types of relays that are popularly used in typical loadcontrol. Tesys lr2k is a range of thermal overload relays from 0. Much like a relay, a contactor is an electrically controlled switch. Power contactors contactors power contactors 3 pole lmx power mini lmnx lmo lml 4 pole lmcx control relays auxiliary contactors lmx0 mini lmn0 definite purpose contactors lcapacitor duty mpx lsingle pole mr features l lentire mnx range is ul listed lspares available for entire range lmx mini contactors provide a unique blend of. In addition to their current ratings and rating for motor circuit control, contactors often have other construction. Bulletin 193 electronic overload relays, provides the most compact and flexible starter component system available. The main difference between the contactor and relay is that, contactor is a high power device while relay is a low power device. The operating system does not have to load an application program, as it is already in rom. Our control contactors come with high flexibility of number and combination of auxiliary contacts.
Electrically, we have transistors and integrated circuits. Freedom series contactors and overload relays contactors 10 accessories 11 thermal overload relays 14 type 2 coordination selection procedure 16 technical data 18 dimensions 33 modular series contactors and overload relays contactors 38 accessories 40 technical data 42 dimensions 47 thermal overload relays 49 technical data 50 dimensions 54. A relay is normally used in appliances below 5kw, while a contactor is preferred when the appliance is heavier. Contactors are used for loads that have high voltages, high currents, or both. Start studying unit 11 contactors, relays, and overloads. What is the difference between a contactor and a relay. Therefore, ssrs have a variety of features that contact relays do not incorporate. Dec 11, 2017 differences between relays and contactors rsp supply. Feb 07, 2010 relays and contactors are functionally same. Selecting a solid state relay or a solid state contactor for. Contactors and relays perform the same task of switching a circuit.
Advantages of solidstate relays over electromechanical. Here you will find our selection of top quality contactors and relays. Power contactors contactors power contactors 3 pole lmx power mini lmnx lmo lml 4 pole lmcx control relays auxiliary contactors lmx0 mini lmn0 definite purpose contactors lcapacitor duty mpx lsingle pole mr features l lentire mnx range is ul listed lspares available for entire range lmx mini contactors provide a unique blend of compactness and convenience lnewly introduced mo. Relays, contactors, solenoids and for more information. Some contactors come with additional auxiliary contacts that may be either no or nc.
They are environmentally friendly, versatile, and flexible. Contactors typically have multiple contacts, and those contacts are usually but not always normallyopen, so that power to the load is. The more expensive the electrical gear, the greater the number of relays that will generally be used. Difference between contactor and relay compare the. The older contactors usually had a dedicated 60hz coil. Several types of contractors qualify as electricians. Advantages of solidstate relays over electromechanical relays. In addition to the nema contactor applications, it also can be used with other types of controllers for applications requiring dp or iec contactors. Difference between ssr and contact relay faq india. A2 iec contactors relays a2 springer controls company 96074 chester road, yulee, fl 32097 904 2250575 fax. Electrical inspectors need to assure that the available shortcircuit current where equipment is being installed does not exceed the rating marked on the equipment. Here are a few of the basic differences that distinguish different types of relay and contactor switches. Dec 09, 2015 contactors contactors are very similar to relays in that they are electromechanical devices. What is the difference between relay and contactor answer francesco the word relay comes from very old times and was used to call a set of horses that pull a car, when a relay of horses got tired they switch it for a fresh one.
Allenbradley product directory rockwell automation. It has the same dimensions and footprint of the esp100 overload relays. Devices switching more than 15 amperes or in circuits rated more than a few kilowatts are usually called contactors. The product offering starts with minicontactors in a compact 12 amp frame size, followed by midicontactors in up to 100 amp frame sizes, and topped off with the powercontactors which offer up to 800 amp frame sizes. Breakdown voltages coil rating coil voltage rating all terminals 60 hz rms contact material electrical life mechanical life nominal open max. Cjx2 2510 lc1 d ac 25a motor magnetic contactor 3 phase 3p 3 pole 1no 220v 380v coil volt cjx2 contacts relay in contactors from pdf. Relays, contactors, solenoids and pdus for high performance applications relays, contactors, solenoids and pdus for high performance applications te connectivity a new powerful source hv relays dc relays and contactors spacequalified relays and contactors 28 vdc contactors 270 vdc contactors ac contactors kilovac high voltage relays. Our nema contactors are known for rugged construction, dependable performance, and. Perhaps the most common industrial use for contactors is the control of electric motors. What is the difference between relay and contactor answer pankaj relay. Iec contactors relays a2 springer controls company 96074 chester road, yulee, fl 32097 904 2250575 fax. The product offering starts with mini contactors in a compact 12 amp frame size, followed by midi contactors in up to 100 amp frame sizes, and topped off with the power contactors which offer up to 800 amp frame sizes.
To turn things on and off, we need devices that are switchable by the application of a current or voltage. Thermal overload relays mt type magnetic contactors the safety cover of magnetic contactor and thermal overload relay is optional. Introduction solid state relays ssrs and solid state contactors sscs are ideally suited for. The main difference between contactors and relays are the loads that they are intended to handle. Our nema contactors are known for rugged construction, dependable performance, and long electrical life. Standards compliance and certifications standards compliance iec 6094741. 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. Every time you turn on a light, fire up a computer or grab a drink from the fridge, you should thank an electrician for delivering the power you need. Relay locations relays are located throughout the entire vehicle. Both of them are electrically operated switches used for control and switching of loads. We offer a full line of versatile and robust contactors for both iec and nema applications.
Heating and cooling equipment require switching devices that are heavy duty and can operate for thousands of cycles. When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name. The difference between a contactor and a relay is the same difference as between a lake and a pond. Most relay coils are intended to operate on voltages that range from 5 to 120 volts ac or dc. Emt6 thermistor overload relay for machine protection. Relays and contactors are electromagnetic switches. The basic principle of operation of the contactor and the relay are the same. Discover schneider electric range of products in contactors and protection relays. This is designated by the 6 at the end of the part number. In this article, we provide all the information you need to select the.
Whether you need commercial offtheshelf products, components that must meet stringent military specifications or highly specialized, customdesigned products, look to te to. Relays and contactors use a variety of technologies to switch signals and power connections. Selecting a solid state relay or a solid state contactor for startstop control of an ac motor by alessandro bosio, motion control business development manager, and paul bachman, fellow engineer crydom, inc. Electrical contractors provide services that keep our lives running smoothly. Plc is not programmed in one of the high language used for programming a computer. Contactors and starters with a broad portfolio that includes everything from phase, voltage and current monitoring relays to motor protection breakers, eaton offers the protection your system needs against equipment failure and danger caused by voltage faults, current.
Relays are used to switch relatively small output and current. A contactor is used for switching of motors, capacitors, lights etc, that drains very high current. Relays and contactors are electrically controlled switching devices. Distant control of ac relays, contactors, and starters. In addition to series impedance, the control circuit wires also exhibit a distributed.
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