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