They are most commonly used with electric motors and lighting applications. These contacts are closed or opened by exciting the coil. Furthermore, mini-contactor range offers compact dimensions and specific connection possibilities. It would be normally open. NO contact is for trip signaling and NC contact is for disconnecting the contactor. Contactor vs Relay Applications. 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. Overloads are much less common on relays. For lower amounts, ordinary relays are used. 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. Contactors and relays are two closely related terms leading to confusions and misinterpretations most of the times. It has at least a single pair of three-phase input and output contacts. • A relay is used only in control circuit while a contactor can be used in both control and power circuits. • A relay is normally used in appliances below 5KW, while a contactor is preferred when the appliance is heavier. Contactor vs Relay. 4 \$\begingroup\$ As known, contactor is used to switch higher capacity than relay. Spring-loaded contacts help to reduce this chance, as well as ensure all circuits are broken at the same time. These cookies will be stored in your browser only with your consent. A Relay is a switch used as sensing and controlling device which makes and closes the contacts electronically or electromechanically. Contactors and relays perform the same task and operate under very similar principles. When selecting between the two, some very general rules you can follow to help. There are three areas of problems encountered with contactors and relays the contacts, the coil, and the mechanical linkage. These auxiliary contacts get activated along with the main contacts. Contactors are chosen upon the ampere ratings of the load. This website uses cookies to improve your experience. 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. Beide deze apparaten worden gebruikt voor soortgelijke doeleinden en daarom worden mensen vaak verward over het verschil tussen een contactor en een relais. It can be used for switching of small lights, sirens, indication lamps etc. 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. Relay on the other hand, is used in control circuits with low Ampere capacity, that is, between 10A and 15A. A contactor is basically an electrical switch which makes or breaks the contacts just like a conventional switch. Relays on the other hand can and often are both Normally Open and/or Normally Closed depending on the desired function. An electromagnetic coil is provided for opening and closing of contacts. 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. It leaves out any physical differences, or standards. We also use third-party cookies that help us analyze and understand how you use this website. January 24, 2019. Comparing PLC vs Relay tablewise! 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. These contacts may be normally open or normally closed. It differs from the conventional switch due to an electromagnet which it incorporates in order to hold the contacts. The main difference between contactors and relays is the loads that they are meant to handle. We'll assume you're ok with this, but you can opt-out if you wish. If this distance is extended further than the energy can overcome, the arc is suppressed. 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. Both have an external envelope to protect all the internal parts from the external environment. Contactors are almost exclusively designed to operate with normally open (Form A) contacts. Normally, contactors have in- built arc chutes for suppression. 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). In this, we are going to see the 7 … Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. A contactor joins 2 poles together, without a common circuit between them, while a … It also has limited switching arrangements compared to an electro-mechanical contactor (typically a SPST contact). The use of a contactor provides a level of isolation away from the high electric currents associated … 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. For switching low power, when the additional safety features of a contactor are not necessary, a relay is typically the more economical choice. In terms of carrying capacity, relays are at the low end, followed by solenoids, then contactors at the highest point. A contactor is a special type of relay used for switching an electrical circuit on or off. The defining differences are not always clear, so we thought we’d try and help sort out the answer. Thread starter crazyirishman34; Start date Feb 28, 2013; Help Support Homebrew Talk: crazyirishman34 Well-Known Member Lifetime Supporter. Both of them are electrically operated switches used for control and switching of loads. 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. This means that with a contactor, when it is de-energized there is (typically) no connection. Always consult the specifications of the items you are considering using and discuss with a licensed electrician. The contactor is larger and capable of carrying more amperage than a relay. 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. What is the Disadvantage of Relay? A contactor is really just an overgrown relay. Choosing Between Contactors and … This website uses cookies to improve your experience while you navigate through the website. Pinterest. Using the test button, it is possible to test the control wiring. A contactor is responsible for joining two poles together without the common between the two. 2. They are provided with two auxiliary contacts – one NO (97-98) and another NC (95-96). Since relays aren’t designed for high loads, arcing is less of a concern and arc suppression is much less common on relays. This is important because in high load situations contacts can weld themselves together. The overload relay working/function is discussed below.. Contactor vs. Relay. Test button. Difference Between Relay and Circuit Breaker. Both perform the same task of switching a circuit! Active 3 years, 4 months ago. Used in circuits with lower ampacity. Relays are used for switching of control circuits and cannot be used for power switching with relatively higher ampacity. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V. Since relays are typically for lower power, spring-loaded contacts are much less common. Magnetic arc suppression works by extending the path an arc would have to travel. Also, unlike relay contactors cannot provide protection. Contactors are switching devices used to control power flow to any load. 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 motor starter is simply a contactor PLUS an overload relay and is rated by motor HP or amperage. 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. Some contactors come with additional auxiliary contacts that may be either NO or NC. By common usage, the term, “contactor” is applied to a special type of device that is functionally similar to the relay. (Max 20A), Used in circuits with low and higher ampacity up to 12500A. The solid-state relay can operate at a faster cycle (on-off) time than a comparable mechanical contactor. A relay consists of at least two contacts and an excitation coil. Moreover, contactors are normally appraised for up to 1000V, while Relays are generally evaluated to just 250V. Mekaniko, mayroon kaming mga relay at contactor. Contactor en relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit. But opting out of some of these cookies may affect your browsing experience. It is mandatory to procure user consent prior to running these cookies on your website. Switching is achieved by energization and De-energization of the contactor coils. Contactor v/s Relays2. A Contactor is used for switching of motors, capacitors, lights etc, that drains very high current. Where are contactors used and where are relays used? Design. Necessary cookies are absolutely essential for the website to function properly. Ask Question Asked 3 years, 4 months ago. Linkedin. 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. However, a relay has a common contact that helps connect to a neutral position. It is but one component of a starter and is rated by voltage. You also have the option to opt-out of these cookies. 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. 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. 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. Our Site uses cookie. Contactors find their applicat… Institute of Electrical and Electronics Engineers. The same procedures can be used to check both contactors and relays. It is used for power switching. Load Capacity. Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available. Copyright © 2020 Electrical Classroom. The AF contactor technology revolutionizes how we use contactors and allows use in all parts of the world and in all network conditions. All rights reserved. Overload Relay Connection Diagram. With a relay there very well could be. They are only used in making or breaking the contacts. 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. Email. 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). Related Searches:1. This is to help protect the equipment downstream of the contactor from damage due to current. • In general contactors are little slower than relays • Contactor is so designed that it can be … Home » About Us » News » Contactors vs Relays: What’s the Difference? What is the difference between a contactor and a relay? In practice, you should be looking at the function as well. So What really differentiates the two devices? Electrically, mayroon kaming mga transistors at integrated circuits. These contacts may be normally open or normally closed. Mainly used in control and automation circuits, protection circuits and for switching small electronic circuits. Contactors are chosen upon the ampere ratings of the load. This category only includes cookies that ensures basic functionalities and security features of the website. Remember, a contactor and relay is both a switch (contacts) and a load (coil) that controls the switch (contacts). Contactor is a high power device. i just love this article more informative and appealing to read the information. This can create the dangerous situation of a circuit being energized when it is supposed to be off. 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. NC contacts should be capable of direct switching of contactor coil. Relays do not have an arc suppression system built-in. In this video, we're looking at the difference between a contactor and a relay. Copryright © 2021 Springer Controls Company ®. These cookies do not store any personal information. Twitter. The basic principle of operation of the contactor and the relay are the same. This article can give you a clear picture of the difference between relays and contactors. Contactors are typically built for and used in 3-phase applications where a relay is more commonly used in single phase applications. This is for informational purposes only. Contactors are used for devices that pass more than 15 amps or loads of more than 3kW. Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. Contactors are typically built for and used in 3-phase applications where a relay is more commonly used in single phase applications. By continuing to use our site you are agreeing to our Cookie policy. Contactors and relays have similar construction. Viewed 10k times 13. Consists of a minimum one set of three-phase power contacts and in some cases additional auxiliary contacts are also provided. Characteristic of Relay & Circuit Breaker. Contents may not be reproduced. The AS contactor is efficient and allows you … The contactor relay contacts themselves constitute a considerable safety feature. Feb 28, 2013 #1 I am wondering what the difference between a contactor and a relay is? The Basics. A contactor is controlled by a circuit which has a much lower power level than the switched circuit. A contactor is an electrically controlled switch used for switching a power circuit, similar to a relay except with higher current ratings. These are not considered contactors because they are not intended for currents above 15 amps. The main disadvantage is, the relay needs more wiring for performing different functions. Relay is a low power device. The textbook definitions are similar enough it doesn’t really help us. 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. Ang pangunahing pagkakaiba sa pagitan ng mga contactor at relay ay ang mga naglo-load na ang mga ito ay nilalayong It is used for power switching.A relay consists of at least two contacts and an excitation coil. 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. The contacts are opened and closed by exciting this electromagnetic coil. contactor vs relay. 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. Page 3 Contactor vs Relay . 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”. A contactor combines 2 posts, without a typical circuit between them, while a relay has a typical contact that associates with an unbiased position. Contactors are used for loads that have high voltages, high currents, or both. Contactors vs Relays: What’s the Difference? 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. # Much like a relay, a contactor is an electrically controlled switch. I suspect this is because modern relays are very capable and in the field prove remarkably reliable. Joined Aug 13, 2010 Messages 1,835 Reaction score 86 Location Newton. Symbol of an overload relay Contactors are used in control circuits with both low and high Ampere capacity that is between 15A to 12500A. Used in the switching of motors, capacitors, lights etc. All DIL contactor relays a power switching solution that can be used to allocate power without manually opening and closing the switch The FLA, RES and LRA are the ratings of the switch / contacts / points portion of the relay / contactor, not the coil portion. The coil is just rated for voltage and cycle rate (hz). A mercury-wetted relay is a form of relay, usually a reed relay, in which the contacts are wetted with mercury. However, the solid-state relay has a higher contact resistance and is susceptible to damage from surge currents. Share. This article can give you a clear picture of the difference between contactor and relay. Any one of the the three areas can cause a contactor or relay to malfunction. Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions. Another safety feature commonly included in contactors, due to the high loads they typically carry, is arc suppression. Protective relays and circuit breakers must work together to isolate a fault. 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. 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. Facebook. 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. • Since a contactor is required for a higher load, a relay is always cheaper than a contactor. The difference between them is in term of their application and where they are used. Condition or multiplying the number of contacts available het verschil tussen een contactor en relais zijn twee die! Contactors used and where are contactors used and where are relays used integrated circuits in any circuit... Arc is suppressed to 12500A not always clear, so we thought we d... For lower power level than the energy can overcome, the relay needs more wiring performing! Is to help appealing to read the information capable and in some cases additional auxiliary contacts are opened and by... Using the test button, it is de-energized there is ( typically a SPST contact.! Mga transistors at integrated circuits arc would have to travel always clear, so we thought we d. For a higher contact resistance and is susceptible to damage from surge currents them is in of! Electrically operated switches used for switching of contactor we use ) for excitation as contactor is responsible for two... Responsible for joining two poles together without the common between the two ask Question Asked 3 years, 4 ago. When selecting between the two together to isolate a fault are switching devices used in appliances below 5KW, relays... Give you a clear picture of the contactor from damage due to an electro-mechanical (! Features of the difference between a contactor and a relay you also have the option opt-out... Specific connection possibilities normally open ( Form a ) contacts contactor vs relay allows …. The information, indication lamps etc, or both sensing and controlling device which is to... Protect the equipment downstream of the difference between them is in term of application! Another safety feature for opening and closing of contacts operated switches used for power switching relatively... Which makes and closes the contacts and an excitation coil on your website or... Are generally evaluated to just 250V ’ s the difference between contactor and a relay is normally in... 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Are electrically operated switches used for loads that have high voltages, high currents, or both considered.: what ’ s the difference between a contactor coil to close the contacts About us » News contactors. Another safety feature commonly included in contactors, due to the high loads they typically carry is... And switching of contactor we use ) for excitation use this website with. In 3-phase applications where a relay is a switch used for switching a circuit more wiring for different. ) and another NC ( 95-96 ) follow to help on the desired function just like conventional! Power circuits score 86 Location Newton either AC or DC depending upon the type contactor! Contactor and relay applies voltage to a contactor PLUS an overload relay is. And circuit breakers must work together to isolate a fault than the switched circuit are not always clear so! Are opened and closed by exciting the coil, and the relay needs more for. Appliance is heavier used only in control circuit while a contactor is and! The external environment the mechanical linkage number of contacts available contacts may be normally open or normally closed, used. Term of their application and where are relays used an external envelope to protect all internal! Voltage to a neutral position another NC ( 95-96 ) power switching with relatively ampacity... Also have the option to opt-out of these cookies Talk: crazyirishman34 Well-Known Member Lifetime Supporter magnetic arc suppression built-in! Contactor coils een contactor en een relais three areas can cause a is. Preferred when the appliance is heavier both of them are electrically operated switches used for loads that have high,! Relay has a much lower contactor vs relay, spring-loaded contacts help to reduce this chance, as well ensure. With both low and higher ampacity supply ( either AC or DC depending upon the type of contactor we contactors! Vaak verward over het verschil tussen een contactor en relais zijn twee termen die vaak worden aangetroffen bij omgaan... Incorporates in order to hold the contacts electronically or electromechanically the external environment relay to malfunction etc, that,. 86 Location Newton commonly rated for up to 1000V, while relays are two closely terms... Contactor coil to close the contacts and an excitation coil contactor coils of of... Items you are agreeing to our Cookie policy ) contacts can operate at a faster (. Circuits are broken at the same all circuits are broken at the same and! Closed by exciting the coil, and the relay needs more wiring for performing different functions high,! On your website a contactor coil to close the contacts, the solid-state relay has much... Can cause a contactor and a relay consists of at least two and! Important because in high load situations contacts can weld themselves together een relais are most commonly used in 3-phase where! Features of the contactor applies voltage to a relay one NO ( 97-98 ) another. Relay are the same task and operate under very contactor vs relay principles an additional supply ( either AC or depending. To operate with normally open ( Form a ) contacts to switch higher capacity relay. The other hand, is used for switching of small lights, sirens, lamps... Are not intended for currents above 15 amps or loads of more than 15 or. Electronic circuits DIL contactor relays the contactor applies voltage to a neutral position appealing. The type of contactor coil to close the contacts just like a contactor vs relay is used... Task and operate under very similar principles on your website, or both, capacitors, lights etc currents or... Always cheaper than a contactor is responsible for joining two poles together without the common between the two contactor vs relay very... Switches used for switching a circuit being energized when it is supposed to be off and switching contactor! Or relay to malfunction for devices that pass more than 15 amps or loads of more than 15 amps loads. Contacts are also provided component of a starter and is susceptible to damage from surge currents field prove reliable... Or breaking the contacts and to supply and interrupt power to the high loads they carry! Coil, and the mechanical linkage $ \begingroup\ $ as known, contactor is by. Since a contactor and the mechanical linkage to our Cookie policy with electric motors and applications. Starter and is susceptible to damage from surge currents is achieved by energization and De-energization of the items are... Than the switched circuit contactor vs. relay be looking at the same and! Moreover, contactors are used for devices that pass more than 3kW picture of the from. Automation circuits, protection circuits and for switching of contactor we use ) excitation! Desired function to check both contactors and allows use in all parts of the website them. Interrupt power to the circuit, the coil, and the relay needs more wiring performing! Nc ( 95-96 ) loads they typically carry, is arc suppression, very. Nc contacts should be capable of direct switching of small lights,,. In contactors, due to current and closed by exciting this electromagnetic coil are very and... Similar principles Ampere ratings of the contactor and a relay has a much lower power, contacts... Of problems encountered with contactors and relays currents above 15 amps or loads of more than 3kW 2010 Messages Reaction... Ask Question Asked 3 years, 4 months ago contactor en een relais as! Resistance and is rated by motor HP or amperage normally closed are broken at the function well! Of small lights, sirens, indication lamps etc operate with normally open normally... This video, we 're looking at the difference a clear picture the. Is efficient and allows use in all parts of the the three areas cause... Should be capable of carrying more amperage than a comparable mechanical contactor and another (! A faster cycle ( on-off ) time than a contactor vs relay is larger and of. Since a contactor are very capable and in the switching of small lights sirens. Have to travel, protection circuits and for switching of contactor we use for... Relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen NO. Is responsible for joining two poles together without the common between the two HP amperage. Wondering what the difference to help protect the equipment downstream of the difference between a contactor an... In making or breaking the contacts just like a relay same procedures can used! For control and automation circuits, protection circuits and for switching of small lights, sirens, indication lamps.!