A contactor is really just an overgrown relay. The contacts are opened and closed by exciting this electromagnetic coil. • A relay is normally used in appliances below 5KW, while a contactor is preferred when the appliance is heavier. In this video, we're looking at the difference between a contactor and a relay. # A contactor combines 2 posts, without a typical circuit between them, while a relay has a typical contact that associates with an unbiased position. The AS contactor is efficient and allows you … These contacts are closed or opened by exciting the coil. 2. It has at least a single pair of three-phase input and output contacts. Where are contactors used and where are relays used? Spring-loaded contacts help to reduce this chance, as well as ensure all circuits are broken at the same time. It is but one component of a starter and is rated by voltage. • In general contactors are little slower than relays • Contactor is so designed that it can be … Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions. Contactors find their applicat… However, a relay has a common contact that helps connect to a neutral position. 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”. Contactors are used for loads that have high voltages, high currents, or both. Difference Between Relay and Circuit Breaker. Contactors and relays perform the same task and operate under very similar principles. The contactor is larger and capable of carrying more amperage than a relay. The same procedures can be used to check both contactors and relays. A contactor joins 2 poles together, without a common circuit between them, while a … Active 3 years, 4 months ago. The contactor relay contacts themselves constitute a considerable safety feature. A contactor is controlled by a circuit which has a much lower power level than the switched circuit. 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 contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. They are most commonly used with electric motors and lighting applications. Ask Question Asked 3 years, 4 months ago. Magnetic arc suppression works by extending the path an arc would have to travel. These contacts may be normally open or normally closed. • A relay is used only in control circuit while a contactor can be used in both control and power circuits. Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. This can create the dangerous situation of a circuit being energized when it is supposed to be off. Linkedin. Relays on the other hand can and often are both Normally Open and/or Normally Closed depending on the desired function. Contactor vs Relay. It is used for power switching.A relay consists of at least two contacts and an excitation coil. NO contact is for trip signaling and NC contact is for disconnecting the contactor. Relays do not have an arc suppression system built-in. 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. Feb 28, 2013 #1 I am wondering what the difference between a contactor and a relay is? Our Site uses cookie. Email. Contactors are chosen upon the ampere ratings of the load. A contactor is a special type of relay used for switching an electrical circuit on or off. 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. Contactors require an additional supply (either AC or DC depending upon the type of contactor we use) for excitation. Beide deze apparaten worden gebruikt voor soortgelijke doeleinden en daarom worden mensen vaak verward over het verschil tussen een contactor en een relais. These auxiliary contacts get activated along with the main contacts. 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. 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). Home » About Us » News » Contactors vs Relays: What’s the Difference? It is mandatory to procure user consent prior to running these cookies on your website. Ang pangunahing pagkakaiba sa pagitan ng mga contactor at relay ay ang mga naglo-load na ang mga ito ay nilalayong Overloads are much less common on relays. It can be used for switching of small lights, sirens, indication lamps etc. Contactors are almost exclusively designed to operate with normally open (Form A) contacts. However, the solid-state relay has a higher contact resistance and is susceptible to damage from surge currents. The textbook definitions are similar enough it doesn’t really help us. By common usage, the term, “contactor” is applied to a special type of device that is functionally similar to the relay. 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). This article can give you a clear picture of the difference between contactor and relay. Contactor en relais zijn twee termen die vaak worden aangetroffen bij het omgaan met elektrische schakelingen. Twitter. The FLA, RES and LRA are the ratings of the switch / contacts / points portion of the relay / contactor, not the coil portion. Always consult the specifications of the items you are considering using and discuss with a licensed electrician. i just love this article more informative and appealing to read the information. This category only includes cookies that ensures basic functionalities and security features of the website. The difference between them is in term of their application and where they are used. 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. Symbol of an overload relay The AF contactor technology revolutionizes how we use contactors and allows use in all parts of the world and in all network conditions. The main disadvantage is, the relay needs more wiring for performing different functions. 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. A Relay is a switch used as sensing and controlling device which makes and closes the contacts electronically or electromechanically. We'll assume you're ok with this, but you can opt-out if you wish. These cookies do not store any personal information. Relays are switching devices used in any control circuit for checking a condition or multiplying the number of contacts available. • Since a contactor is required for a higher load, a relay is always cheaper than a contactor. In terms of carrying capacity, relays are at the low end, followed by solenoids, then contactors at the highest point. Mainly used in control and automation circuits, protection circuits and for switching small electronic circuits. Contactors vs Relays: What’s the Difference? Remember, a contactor and relay is both a switch (contacts) and a load (coil) that controls the switch (contacts). The basic principle of operation of the contactor and the relay are the same. Moreover, contactors are normally appraised for up to 1000V, while Relays are generally evaluated to just 250V. 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. These cookies will be stored in your browser only with your consent. Viewed 10k times 13. 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. Relay is a low power device. Contactors and relays have similar construction. Contactors are used for devices that pass more than 15 amps or loads of more than 3kW. With a relay there very well could be. Contactor is a high power device. This website uses cookies to improve your experience while you navigate through the website. 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. It is used for power switching. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V. Protective relays and circuit breakers must work together to isolate a fault. Since relays aren’t designed for high loads, arcing is less of a concern and arc suppression is much less common on relays. Pinterest. The overload relay working/function is discussed below.. This website uses cookies to improve your experience. Used in circuits with lower ampacity. 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. Using the test button, it is possible to test the control wiring. This article can give you a clear picture of the difference between relays and contactors. Load Capacity. 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. Choosing Between Contactors and … Both have an external envelope to protect all the internal parts from the external environment. Joined Aug 13, 2010 Messages 1,835 Reaction score 86 Location Newton. Are opened and closed by exciting this electromagnetic coil is provided for opening and of. Solid-State relay can operate at a faster cycle ( on-off ) time than a contactor and a relay a... Control wiring user consent prior to running these cookies mini-contactor range offers compact dimensions and specific connection possibilities uses to... Where they are provided with two auxiliary contacts are also provided a single pair three-phase. 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