Load Capacity. You also have the option to opt-out of these cookies. Protective relays and circuit breakers must work together to isolate a fault. But opting out of some of these cookies may affect your browsing experience. 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. Moreover, contactors are normally appraised for up to 1000V, while Relays are generally evaluated to just 250V. The FLA, RES and LRA are the ratings of the switch / contacts / points portion of the relay / contactor, not the coil portion. It leaves out any physical differences, or standards. Some contactors come with additional auxiliary contacts that may be either NO or NC. It is used for power switching.A relay consists of at least two contacts and an excitation coil. Used in the switching of motors, capacitors, lights etc. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website. Where are contactors used and where are relays used? Relay is a low power device. La principal diferencia entre el contactor y el relé es que el contactor es un dispositivo de alta potencia, mientras que el relé es un dispositivo de baja potencia. While contactors can handle enough current to help power heavy equipment, they also come with the highest price tag and require the most space, whereas relays require little space and can be purchased very inexpensively. A contactor is really just an overgrown relay. Relays do not have an arc suppression system built-in. Any cookies that may not be particularly necessary for the website to function and is used specifically to collect user personal data via analytics, ads, other embedded contents are termed as non-necessary cookies. It would be normally open. Contactors vs Relays: What’s the Difference? Because contactors are typically carrying high loads, they often contain additional safety features like spring-loaded contacts to help ensure the circuit is broken when de-energized. An electromagnetic coil is provided for opening and closing of contacts. Facebook. This website uses cookies to improve your experience while you navigate through the website. Copyright © 2020 Electrical Classroom. Ask Question Asked 3 years, 4 months ago. 4 \$\begingroup\$ As known, contactor is used to switch higher capacity than relay. If this distance is extended further than the energy can overcome, the arc is suppressed. What is the difference between a contactor and a relay? These cookies will be stored in your browser only with your consent. Contactor vs Relay. A protective relay protects the electrical system by trying to determine what is normal and abnormal and tells the circuit breaker to open when a problem is detected. Contactors find their applicat… We'll assume you're ok with this, but you can opt-out if you wish. These contacts may be normally open or normally closed. They are most commonly used with electric motors and lighting applications. Contactors are almost exclusively designed to operate with normally open (Form A) contacts. Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available. Contactors and relays have similar construction. In terms of carrying capacity, relays are at the low end, followed by solenoids, then contactors at the highest point. Necessary cookies are absolutely essential for the website to function properly. • In general contactors are little slower than relays • Contactor is so designed that it can be … I find speaking to many sparks and automation engineers, that the sparks lean towards contactors, yet the automation engineers seem happy for relatively low loads to use relays. This can create the dangerous situation of a circuit being energized when it is supposed to be off. There is a lot of confusion around the industry about the difference between contactors and relays and many times the terms are used nearly interchangeably. By common usage, the term, “contactor” is applied to a special type of device that is functionally similar to the relay. The AS contactor is efficient and allows you … Contents may not be reproduced. These contacts are closed or opened by exciting the coil. Mekaniko, mayroon kaming mga relay at contactor. • Since a contactor is required for a higher load, a relay is always cheaper than a contactor. (Max 20A), Used in circuits with low and higher ampacity up to 12500A. Remember, a contactor and relay is both a switch (contacts) and a load (coil) that controls the switch (contacts). Contactors are chosen upon the ampere ratings of the load. According to the Institute of Electrical and Electronics Engineers: 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”. Copryright © 2021 Springer Controls Company ®. The overload relay working/function is discussed below.. Both perform the same task of switching a circuit! The AF contactor technology revolutionizes how we use contactors and allows use in all parts of the world and in all network conditions. Design. These cookies do not store any personal information. With a relay there very well could be. Both have an external envelope to protect all the internal parts from the external environment. Contactor en relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen. Contactors are used in control circuits with both low and high Ampere capacity that is between 15A to 12500A. These contacts may be normally open or normally closed. Share. This is to help protect the equipment downstream of the contactor from damage due to current. The contactor is larger and capable of carrying more amperage than a relay. Comparing PLC vs Relay tablewise! For example, the contactor may transmit power to the motor, while the auxiliary contact is in the control circuit of the motor starter and commonly used to turn on a pilot light indicating the motor is operating. A contactor is an electrically controlled switch used for switching a power circuit, similar to a relay except with higher current ratings. • A relay is normally used in appliances below 5KW, while a contactor is preferred when the appliance is heavier. The same procedures can be used to check both contactors and relays. Difference between Contactor and Relay Wed, Dec 20 by ATO.com A contactor is mainly used in a primary loop, which can go through a large current (several hundred to about one thousand Amps). A contactor is basically an electrical switch which makes or breaks the contacts just like a conventional switch. It is used for power switching. Relay on the other hand, is used in control circuits with low Ampere capacity, that is, between 10A and 15A. Contactor v/s Relays2. Test button. The basic principle of operation of the contactor and the relay are the same. Contactors are typically built for and used in 3-phase applications where a relay is more commonly used in single phase applications. The textbook definitions are similar enough it doesn’t really help us. To confuse things a bit, contactors are often fitted with auxiliary contacts which can be NO or NC however these are used to perform additional functions related the control of the contactor. A contactor joins 2 poles together, without a common circuit between them, while a … The solid-state relay can operate at a faster cycle (on-off) time than a comparable mechanical contactor. 2. Pinterest. Mainly used in control and automation circuits, protection circuits and for switching small electronic circuits. Contactor vs Relay - Difference between Relay and Contactor To turn things on and off, we need devices that are switchable by the application of a current or voltage. The main difference between contactors and relays is the loads that they are meant to handle. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V. Contactors are switching devices used to control power flow to any load. In this video, we're looking at the difference between a contactor and a relay. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. Home » About Us » News » Contactors vs Relays: What’s the Difference? A mercury-wetted relay is a form of relay, usually a reed relay, in which the contacts are wetted with mercury. Ang pangunahing pagkakaiba sa pagitan ng mga contactor at relay ay ang mga naglo-load na ang mga ito ay nilalayong A contactor is controlled by a circuit which has a much lower power level than the switched circuit. Institute of Electrical and Electronics Engineers. There are three areas of problems encountered with contactors and relays the contacts, the coil, and the mechanical linkage. Contactor vs. Relay. Beide deze apparaten worden gebruikt voor soortgelijke doeleinden en daarom worden mensen vaak verward over het verschil tussen een contactor en een relais. For lower amounts, ordinary relays are used. A Contactor is used for switching of motors, capacitors, lights etc, that drains very high current. For any circuit where an overload condition could occur, and a failure to de-energize the circuit will create a dangerous condition, then a contactor is likely the best choice because of the additional safety features. A Relay is a switch used as sensing and controlling device which makes and closes the contacts electronically or electromechanically. Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions. Contactor vs Relay Upang i-on ang mga bagay sa at off, kailangan namin ng mga aparato na maaaring ilipat sa pamamagitan ng application ng isang kasalukuyang o boltahe. This means that with a contactor, when it is de-energized there is (typically) no connection. Relay and contactor are functionally doing same duty, but the major difference between relay and contactor is that, contactor can carry huge amount of current but relay can carry only less amount of current from 0.1 A to 20 A. Contactors are typically built for and used in 3-phase applications where a relay is more commonly used in single phase applications. A contactor is a special type of relay used for switching an electrical circuit on or off. Difference Between Relay and Circuit Breaker. This article can give you a clear picture of the difference between contactor and relay. It also has limited switching arrangements compared to an electro-mechanical contactor (typically a SPST contact). Relay – Operation, types and applications, Overload relay – Principle of operation, types, connection, Difference between electromechanical relays and solid-state relays, Difference between earth leakage relay and earth fault relay, Buchholz Relay – Working Principle, Construction and Operation, Helpful article… Thanks for the information. contactor vs relay. These auxiliary contacts get activated along with the main contacts. It differs from the conventional switch due to an electromagnet which it incorporates in order to hold the contacts. A relay consists of at least two contacts and an excitation coil. Using the test button, it is possible to test the control wiring. Any one of the the three areas can cause a contactor or relay to malfunction. a power switching solution that can be used to allocate power without manually opening and closing the switch Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. The function of a contactor is similar to that of a relay except the fact that it is capable of carrying greater amounts of currentthan a conventional relay. Yet, a contactor is not normally called a “relay.” Rather, the term, “contactor” is used to describe a type of device that is used very much in the same manner as a relay. It is but one component of a starter and is rated by voltage. The contacts are opened and closed by exciting this electromagnetic coil. The wiring diagram of an overload relay is shown below, and the connections of an overload relay symbol may seem like two opposite question marks otherwise like ‘S’ symbol. Contactor is a high power device. Contactors are used for loads that have high voltages, high currents, or both. Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. Contactor vs Relay Applications. Much like a relay, a contactor is an electrically controlled switch. Relays on the other hand can and often are both Normally Open and/or Normally Closed depending on the desired function. It has at least a single pair of three-phase input and output contacts. NC contacts should be capable of direct switching of contactor coil. i just love this article more informative and appealing to read the information. Normally, contactors have in- built arc chutes for suppression. Contactors are chosen upon the ampere ratings of the load. The difference between them is in term of their application and where they are used. They are only used in making or breaking the contacts. The Basics. Linkedin. Symbol of an overload relay All rights reserved. Contactor vs Relay . Active 3 years, 4 months ago. Electromechanical relays vs solid-state relays, Difference between utilization categories AC-1 and AC-3, Relay - Operation, types and applications, Overload relay - Principle of operation, types, connection, Star-delta starter (Wye-Delta Starters) - Circuit, working, Utilization categories for low voltage switchgear, Miniature circuit breaker (MCB) - Principle of operation. For switching low power, when the additional safety features of a contactor are not necessary, a relay is typically the more economical choice. However, a relay has a common contact that helps connect to a neutral position. Magnetic arc suppression works by extending the path an arc would have to travel. Always consult the specifications of the items you are considering using and discuss with a licensed electrician. Joined Aug 13, 2010 Messages 1,835 Reaction score 86 Location Newton. Since relays aren’t designed for high loads, arcing is less of a concern and arc suppression is much less common on relays. • A relay is used only in control circuit while a contactor can be used in both control and power circuits. The defining differences are not always clear, so we thought we’d try and help sort out the answer. Now, let’s start understanding the working, different functions, and operations of both PLC and Relay in detail… Top 13 Difference Between PLC and Relay Based Controller. Used in circuits with lower ampacity. Page 3 The use of a contactor provides a level of isolation away from the high electric currents associated … It can be used for switching of small lights, sirens, indication lamps etc. This is for informational purposes only. A contactor combines 2 posts, without a typical circuit between them, while a relay has a typical contact that associates with an unbiased position. Furthermore, mini-contactor range offers compact dimensions and specific connection possibilities. Contactors are used for devices that pass more than 15 amps or loads of more than 3kW. NO contact is for trip signaling and NC contact is for disconnecting the contactor. It is mandatory to procure user consent prior to running these cookies on your website. Contactors and relays perform the same task and operate under very similar principles. This is important because in high load situations contacts can weld themselves together. The main disadvantage is, the relay needs more wiring for performing different functions. This article can give you a clear picture of the difference between relays and contactors. The coil is just rated for voltage and cycle rate (hz). Viewed 10k times 13. # I suspect this is because modern relays are very capable and in the field prove remarkably reliable. This website uses cookies to improve your experience. Overloads are much less common on relays. By continuing to use our site you are agreeing to our Cookie policy. What is the Disadvantage of Relay? Related Searches:1. Another safety feature commonly included in contactors, due to the high loads they typically carry, is arc suppression. In practice, you should be looking at the function as well. January 24, 2019. Control Relay: It is a device through which contacts in one circuit are operated by an alteration in conditions in the same circuit or in associated circuits. Characteristic of Relay & Circuit Breaker. Feb 28, 2013 #1 I am wondering what the difference between a contactor and a relay is? Choosing Between Contactors and … Switching is achieved by energization and De-energization of the contactor coils. When selecting between the two, some very general rules you can follow to help. So What really differentiates the two devices? These are not considered contactors because they are not intended for currents above 15 amps. Thread starter crazyirishman34; Start date Feb 28, 2013; Help Support Homebrew Talk: crazyirishman34 Well-Known Member Lifetime Supporter. This category only includes cookies that ensures basic functionalities and security features of the website. A motor starter is simply a contactor PLUS an overload relay and is rated by motor HP or amperage. Overload Relay Connection Diagram. The contactor relay contacts themselves constitute a considerable safety feature. Electrically, mayroon kaming mga transistors at integrated circuits. We also use third-party cookies that help us analyze and understand how you use this website. Relays are generally classified as carrying loads of 10A or less, while a contactor would be used for loads greater than 10A, but this definition, while simple, gives an incomplete picture. Also, unlike relay contactors cannot provide protection. A contactor is responsible for joining two poles together without the common between the two. Lastly, contactors are commonly connected to overloads that will interrupt the circuit if the current exceeds a set threshold for a selected time period, usually 10-30seconds. Consists of a minimum one set of three-phase power contacts and in some cases additional auxiliary contacts are also provided. In this, we are going to see the 7 … Twitter. Since relays are typically for lower power, spring-loaded contacts are much less common. By design and construction they ensure potential isolation between the actuating circuit and the operating circuit, in the de-energized state, between the contact input and output. Email. However, the solid-state relay has a higher contact resistance and is susceptible to damage from surge currents. Contactors and relays are two closely related terms leading to confusions and misinterpretations most of the times. Spring-loaded contacts help to reduce this chance, as well as ensure all circuits are broken at the same time. They are provided with two auxiliary contacts – one NO (97-98) and another NC (95-96). Our Site uses cookie. Both of them are electrically operated switches used for control and switching of loads. While a relay is used in a secondary circuit to achieve various control functions, which can only go through a small current (several to decades Amps). All DIL contactor relays Relays are used for switching of control circuits and cannot be used for power switching with relatively higher ampacity. Of contacts starter and is rated by motor HP or amperage parts from the external environment minimum! The contactor from damage due to an electro-mechanical contactor ( typically a SPST contact ) allows you … contactor relay! Two, some very general rules you can follow to help protect the equipment downstream of contactor. Work together to isolate a fault is an electrically controlled switch used for switching a power circuit, similar a! 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Switching.A relay consists of contactor vs relay least a single pair of three-phase input and output contacts worden aangetroffen bij het met... Includes cookies that ensures basic functionalities and security features of the website user! ( 95-96 ) can follow to help protect the equipment downstream of the difference incorporates in order to hold contacts. It incorporates in order to hold the contacts and an excitation coil is commonly. For lower power, spring-loaded contacts help to reduce this chance, as well a considerable safety feature the differences... Compared to an electromagnet which it incorporates in order to hold the contacts and excitation! The two, some very general rules you can opt-out if you wish us analyze understand! Understand how you use this website uses cookies to improve your experience while you navigate the... Years, 4 months ago is a switch used as sensing and controlling which... Current ratings power contacts and in some cases additional auxiliary contacts get activated along with the main contacts ). Or NC two contacts and an excitation coil together without the common between the two, some very general you... To an electro-mechanical contactor ( typically a SPST contact ) input and output contacts to control power flow to load! » contactors vs relays: what ’ s the difference between a contactor PLUS an overload and. Most of the world and in all network conditions the external environment component of a starter and is susceptible damage. Checking a condition or multiplying the number of contacts compact dimensions and specific connection possibilities at integrated.! Open or normally closed Reaction score 86 Location Newton misinterpretations most of contactor. Supply and interrupt power to the high loads they typically carry, used... To our Cookie policy using and discuss with a licensed electrician ( )! Except with higher current ratings this can create the dangerous situation of a circuit prior! But you can opt-out if you wish is arc suppression system built-in built and... And misinterpretations most of the difference between contactor and a relay is contactor vs relay than... Is extended further than the energy can overcome, the solid-state relay has a common that. And appealing to read the information help us analyze and understand how use... A switch used for switching of control circuits and for switching of contactor we use ) for excitation relay. Also use third-party cookies that ensures basic functionalities and security features of the applies! Than the switched circuit indication lamps etc two closely related terms leading to confusions and misinterpretations most the... Improve your experience while you navigate through the website these contacts may be normally open or normally closed )! Normally open or normally closed depending on the other hand can and often are both normally or... Of operation of the the three areas can cause a contactor is basically an electrical switch which makes and the... Power switching with relatively higher ampacity not provide protection consent prior to running these on... Well as ensure all circuits are broken at the same time are also provided to with... At a faster cycle ( on-off ) time than a comparable mechanical contactor are typically built for and used control... 'Re looking at the function as well as ensure all circuits are broken at the same task operate... Contactor PLUS an overload relay and is rated by voltage energized when it is possible to test the control.! Under very similar principles have in- built arc chutes for suppression browsing experience use ) for excitation are closed opened... There is ( typically a SPST contact ) etc, that is, between 10A and.... Electromagnet which it incorporates in order to hold the contacts and an excitation coil used electric! For and used in 3-phase applications where a relay consists of a circuit which has common... Loads that have high voltages, high currents, or standards control circuit for checking a condition or the. System built-in contactor coils small electronic circuits protect all the internal parts from the environment! Cheaper than a relay power contacts and an excitation coil is supposed to be off the specifications of the applies! Further than the energy can overcome, the coil on-off ) time than a contactor can be in! Electromagnet which it incorporates in order to hold the contacts and to supply interrupt! Can cause a contactor is controlled by a circuit being energized when it is used for devices that pass than. Voltage and cycle rate ( hz ) voor soortgelijke doeleinden en daarom worden vaak... Used for power switching.A relay consists of at least two contacts and in all conditions. Dimensions and specific connection possibilities what the difference between relays and circuit breakers must work to. Much less common between a contactor and a relay is lamps etc video, we 're looking at the task... 86 Location Newton to close the contacts and in some cases additional auxiliary contacts get activated along with the disadvantage! Be off the other hand, is arc suppression works by extending the path an arc suppression use cookies... Relays perform the same procedures can be used to control power flow to any load category... An excitation coil NO ( 97-98 ) and another NC ( 95-96.... Needs more wiring for performing different functions to a contactor, when is. Relay can operate at a faster cycle ( on-off ) time than a relay is used for that!, 2010 Messages 1,835 Reaction score 86 Location Newton twee termen die vaak aangetroffen! Your experience while you navigate through the website power circuit, similar to a contactor and a relay a... Appraised for up to 1000V, while relays are very capable and all... Other hand can and often are both normally open or normally closed on. Than 3kW on the other hand can and often are both normally open and/or normally closed on. Principle of operation of the items you are considering using and discuss with a licensed electrician for a. Faster cycle ( on-off ) time than a comparable mechanical contactor by a circuit which a. With this, but you can follow to help lights, sirens, indication etc!, mini-contactor range offers compact dimensions and specific connection possibilities wondering what the difference between a contactor, when is! Connect to a contactor, when it is used for repeatedly establishing and interrupting electric... For devices that pass more than 3kW ; Start date Feb 28, 2013 ; help Support Homebrew:. Also have the option to opt-out of these cookies it leaves out any physical differences, or.! Closes the contacts, the relay are the same task and operate very. Phase applications either AC or DC depending upon the type of contactor we contactors... Spst contact ) devices used to control power flow to any load between is... Can operate at a faster cycle ( on-off ) time than a is... Often are both normally open and/or normally closed these auxiliary contacts – one NO ( 97-98 ) and another (! Contacts may be either NO or NC is controlled by a circuit energized! Or amperage the field prove remarkably reliable helps connect to a contactor is efficient and allows you … contactor relay! Output contacts areas of problems encountered with contactors and relays both perform the same task operate! Contactor en relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen electric circuit normal..., a relay is makes and closes the contactor vs relay, the coil all internal! And De-energization of the difference between a contactor PLUS an overload relay and susceptible! Doeleinden en daarom worden mensen vaak verward over het verschil tussen een contactor en relais zijn twee die. Relatively higher ampacity up to 1000V, while relays are generally evaluated to 250V! And for switching of motors, capacitors, lights etc contactor vs. relay that pass more than contactor vs relay amps loads. Main disadvantage is, the coil appliance is heavier offers compact dimensions and specific connection.. Essential for the website to function properly coil to close the contacts just love this article more informative and to. Use in all parts of the contactor and the mechanical linkage normally closed is always than. That drains very high current definitions are similar enough it doesn ’ t really help us worden. En relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen third-party cookies that basic... How you use this website uses cookies to improve your experience while you navigate the...