Products include hermetically sealed mil qualified, electromechanical relays such as t05. In particular, large electrical gear as generators, motors and. Dimensions stancor coil resistance inductive load inches part duty terminal pole bracket volt. A starter has overload protection devices, while a contactor doesnt. Electrical contractors provide services that keep our lives running smoothly. Contactors generally are spring loaded to prevent contact welding. Relays are used in a wide variety of applications like electric power systems, home. The relay is an automatic protective and switching device which is capable of sensing abnormal conditions in electrical circuits. Contactors are used for devices that pass more than 15 amps or loads of more than 3kw. Class 14 esp100 starters use the same contactors as class 14 nema starters equipped with bimetal overload relays for nema sizes 00 through 4, but are supplied with a class 10, 20, or 30 esp100 solidstate overload relay. Contactors are nothing more than a coil and a set of contacts. Click for 8 page shortform pc, c and mc series or click for full 76 page.
Differences between a relay and a contactor in addition to their current ratings and rating for motor circuit control, contactors often have other construction details not found in relays. The difference between contactors and relays is the loads they are meant to handle. Relay operation all relays operate using the same basic principle. Much like a relay, a contactor is an electrically controlled switch. Timing is the other fault detection method safety relays. The contactor applies voltage to a contactor coil to close the contacts and to supply and interrupt power to the circuit.
The res rating is the resistive load ampacity amperage capacity or rating. They both are commonly used in industrial and commercial applications, and function in almost the exact same way. The main difference between contactors and relays is the loads that they are meant to handle. If you see from the application point of view, you would have seen contactors placed in control panels of industrial motors or other heavy loads. The only difference between them is their power rating. Power rating of contactors are more than the relays. It has at least a single pair of three phase input and output contacts. We offer the best quality hvac contactors and relays you can find. Explain the difference between a manual contactor and a magnetic contactor. Model c contactor a threephase starter b singlephase starter type.
Bulletin 104k reversing contactors are factory assembled and include contactors, mechanical interlock cat. They are used in large quantities for the indirect control of motors, valves, clutches and heating equipment. Electrical contactors and relays hvac parts online. Contactors electromechanical relays electronics textbook. Basically, its just two different names for the same thing. Relay on the other hand, is used in control circuits with low ampere capacity, that is, between 10a and 15a. A contactor function is same as a circuit breaker or switch but the working principle is different. Secure uptime and optimize stocks with af latest technology up to 2850 a. Relays and contactors use a variety of technologies to switch signals and power connections. Relays tend to be of lower capacity and are usually designed for both normally closed and normally open applications. A device by which contacts in one circuit are operated by a change in conditions in the same circuit or in one or. Electrically, we have transistors and integrated circuits. Contactors and relays perform the same task of switching a circuit. Compensated relays with manual or automatic reset, with relay trip indicator for ac or dc.
Contactors are rated by designed load current per contact pole, maximum fault withstand current, duty cycle, design life expectancy, voltage, and coil voltage. At es electronics, we pride ourselves on being among the industrys leading contactor and relay distributors. Relays and contactors application areas and power ratings are the two main factors that differentiate relays from contactors though both styles of devices may use. What are the coil voltage codes used for contactors and. Contactors are used for loads that have high voltages, high currents, or both. This section explains the differences between a circuit breaker and a contactor, which both make and break a circuit. One reading you may overlook is the res ampacity of the contactor or relay. Difference between contactor and relay since a contactor is required for a higher load, a relay is always cheaper than a contactor.
Contactor relays are often used in control and regulating functions. Relays or relay switches control comparatively lowvoltage equipment such as a 120v or 240v well pump or furnace or heating boiler or air conditioners. The coil of the contactor can be 24, 115, or 230 v, and even higher depending on the application. Additionally, contactors are commonly rated for up to v, while relays are usually rated to only 250v. Dec 04, 2018 relays and contactors are electrically controlled switching devices. The different contactors accomplish the same thing, but they do it in different ways, starting with how they are constructed.
Here you will find our selection of top quality contactors and relays. As fully authorized, franchised distributor of relays and contactors, we have contracts with some of the worlds finest manufacturers, including cole hersee, general electric, furnassiemens, klocknermoeller, omron, and tycote connectivity. We offer a full line of versatile and robust contactors for both iec and nema applications. Tesys d class 10 and 20 overload relays standard tripping time. 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. Electrical standards for contactors ac1, ac2, ac3, ac4. Ive expanded the original question from what are the differences between relays, contactors and motor starters.
Additionally, contactors are commonly rated for up to v, while relays. By design and construction they ensure electrical isolation between the actuating circuit and the operating circuit, in the deenergized state, between the contact input and output. Af contactors 3pole contactors and overload relays for. Today were going to talk about selecting a contactor. Mar 25, 2015 this feature is not available right now. To complement the contactors, thermal overloads are offered for each frame size, available in several setting ranges. Time delay, latching attachments, overlapping, and logic reed contacts can be combined into one relay. A relay is normally used in appliances below 5kw, while a contactor is preferred when the appliance is heavier. The main difference between a circuit breaker and a contactor. Pg03407001u june 2006 contactors and overload relays 19 contactors and overload relays 4 contactors and overload relays this chapter provides product selection guidance for eatons xt range of contactors, overload relays and accessories which includes nonreversing and reversing contactors, frame sizes b through r, 20a. Unit 19 motor controls big book flashcards quizlet. A reader submitted a question through the ask chris form. Definite purpose contactors and starters 040a compact contactor 2560a starter.
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. Heating and cooling equipment require switching devices that are heavy duty and can operate for thousands of cycles. Mar 12, 2017 mechanically, we have relays and contactors. 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. Understanding relays page 4 autoshop, all rights reserved. This guide offers an overview of our relays and contactors product range. The motor statrter is made up of a contactor with an overload relay attached physically and electrically to it. Contactors are used in control circuits with both low and high ampere capacity that is between 15a to 12500a. Contactors are used for loads that have high voltages and. Feb 07, 2010 relays and contactors are functionally same.
What is the difference between a contactor and a relay. What is the main difference between a contactor and a magnetc motor started. Contactors are mainly designed for three phase applications whereas. Nov 23, 2015 a contactor is an electrically controlled switch used for switching an electrical power circuit, similar to a relay except with higher current ratings. Etsnz what is the difference between bd and bl 24vdc control in the tesys contactor lc1d0938 range. A motor starter is simply a contactor plus an overload relay and is rated by motor hp or amperage. Difference between ac1 and ac3 contactors is ac1 contactor are used for less inductive loads such as resistive loads the power factor of the load is near about 1 but ac3 duty contactors.
Main difference between contactor and starter electrical. Some contactors come with additional auxiliary contacts. The phase difference between these two fluxes produces necessary torque to rotate the disc. The arcs produce additional heat, which, if continued, can damage the contact surfaces. What are the coil voltage codes used for contactors and relays. To turn things on and off, we need devices that are switchable by the application of a current or voltage. V5t438 product overview eaton offers the most complete line of definite purpose dp contactors in. What is the difference between relay and contactor answer pankaj relay. Etsnz what is the difference between bd and bl 24vdc.
Alternating current ac and direct current dc contactors are found in many industrial motors, including many automobiles. If there is no overload relay it is not a starter any longer. Contactors and relays contactor relays moeller wiring manual 0208 53 5 the system and the standard european standard en 50011 terminal markings, reference numbers and reference letters for certain contactor relays has a direct bearing on the use and application of the modular system. Operating temperature 11 to 140f 24 to 60c mounting plug in weight b185k 0. Difference between contactor and relay compare the. Contactors and overload relays 4 allied electronics. What are the differences between a relay and solenoid. 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. Hence contactors are used in the switching of heavy loads and power circuits whereas relays are used in the switching of. Difference between ac1 and ac3 contactors is ac1 contactor are used for less inductive loads such as resistive loads the power factor of the load is near about 1 but ac3 duty contactors are used for high inductive, squirrel cage motors which will be off during the motor is running condition. Electrical controls for heating and air conditioning, contactors, relays, transformers, sequencers, time delays. For instance, if a switch or circuit breaker is at on position and a control system sends an open operation signal, it will not open the circuit until someone open the switch manually or it will melt or burn.
Things like terminal ambient temperature ratings and torque specs. Difference between contactor and relay difference between. The more expensive the electrical gear, the greater the number of relays that will generally be used. Contactors, and relays for hvac are available at wholesale and quantity pricing. The functional or usage difference between a contactor and a relay is that.
Shop our parts hvac online store for transformers, contactors, and relays hvac supplies and accessories. When a relay is used to switch a large amount of electrical power through its contacts, it is designated by a special name. Relays, just like contactors, are devices that are used to open or close circuits electromechanically or electronically. Some contactors come with additional auxiliary contacts that may be either no or nc.
How to size a contactor for any application springer. A general purpose motor control contactor may be suitable for heavy starting duty on large motors. 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. Iec contactors and overload relays technical solutions mini series contactors and overload relays freedom series contactors and overload relays modular series contactors and overload relays mini series contactors and overload relays contactors 2 contactors reversing 2 accessories 3 technical data 4 lighting circuit switching 6 overload relay 7. Start studying unit 11 contactors, relays, and overloads. Perhaps the most common industrial use for contactors is the control of electric motors. Look closely at a contactor on your truck and you may find some interesting ratings you never noticed. Color of indicator changes from green to red after the contactor is closed. A contactor is an electrical device which is used for switching an electrical circuit on or off. The difference between a contactor and a relay is the same difference as between a lake and a pond. Several types of contractors qualify as electricians. The watthour structure type relay works as an electromagnetic induction type of watthour a.
Breakdown voltages coil rating coil voltage rating all terminals 60 hz rms contact material electrical life mechanical life nominal open max. Thermal overload relays mt type magnetic contactors the safety cover of magnetic contactor and thermal overload relay is optional. Contactors are used in applications ranging from the light switch to the most. 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. The basic principle of operation of the contactor and the relay are the same. Why is it not a good idea to file or sand the contactor.
In my perspective, a relay is an electromagnetic operated switch an electromagnetic coil with a combination of mechanically linked contact points that are. Dec 11, 2017 much like a relay, a contactor is an electrically controlled switch. The still use a coil, that when energized, will close the contacts. 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 circ. Beta machinedesign com sites machinedesign com files ssr diagram 2. In previous blog posts, we talked about the differences between iec vs. However, the basic difference between the relay and contactor is that the contactor is used in applications with higher current carrying capacity, whereas the relay. 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. A contactor is used for switching of motors, capacitors, lights etc, that drains very high current. Pdf download characiformes books for free written by source wikipedia and has been published by books llc, wiki series this book supported file pdf, txt, epub, kindle and other format this book has been release onwith categories. They both are commonly used in industrial and commercial applications, and. Mid range relays 5a to 50a and time delay relays, as well as a high current and high voltage range of relays and contactors, up to.
Contactor vs relay difference between relay and contactor. A safety relay detects wire breaks and faulty contactorsactuators by sending out electrical pulses through the wiring. 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. Generally, relays are smaller than contactors, just as ponds are generally smaller than lakes. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Bulletin 700p, 700ph and 700pk heavy duty relays have four types of contact cartridges to meet your specific switching requirements. Contactors and relays page contactor relays 52 contactors dil, overload relays z 58 contactors dil 514 overload relays z 520 zeb electronic overload relay 523 zev electronic motorprotective system 526 thermistor overload relay for machine protection emt6 533 cmd contactor. What is the difference between a contactor and a starter. Also find hard to find transformers, contactors, and relay replacement parts.
A relay is normally used in appliances below 5kw, while a contactor. Unlike relays, contactors are designed to make and break higher powered circuits without being damaged. Relays, contactors, solenoids and for more information pdus. By measuring flow of current the safety relay checks for welded contact sets and wire breaks. A magnetic starter is essentially a contactor with built in overload protection.
Emt6 thermistor overload relay for machine protection. Contactor vs relay electrical engineering stack exchange. Difference between circuit breaker and isolator disconnector. 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. These are operated to open or close the load contacts in response to one or more electrical quantities like voltage and current. Relays are mainly designed for single phase application.
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