What is a Contactor? | Working Principles

[@anonymous2554]

It's been more helpful this channel than my career in more than one aspect.

[@realpars]

What an amazing compliment! Many thanks

[@diwasshah7545]

Totally Agree 🙏

[@leandroalmeida9689]

I'm going through the greatest challenge of my life: becoming an automation engineer in a industrial plant. I've got a degree in electrical engineering, which was more related to power supply systems, but not so much to automation... however, I accept the challenge anyway! And I have to thank You for sharing this knowledge in a so wonderful way! It's been very helpful for beginners like me!

[@realpars]

We truly appreciate your support, Leandro! We're happy to hear that our video courses are helping you. If you have any questions along the way, please feel free to reach out.

[@kenmichaels6595]

Probably one of the most lucid presentations on contactors I've run across. Great job!

[@realpars]

Thank you very much, Ken! Much appreciated

[@davidalvarado7944]

This was so helpful and helped me embarrass my lead for trying to troubleshoot a broken contactor incorrectly when it was working just fine!!! thanks a bunch RealPars

[@realpars]

You're very welcome, David! Glad to hear that our video course has been helpful!

[@mahuk.]

So glad I found this channel when I was starting my career. Your videos are always so easy to understand with the good narrative and the images. Than you so much. One day I'll come back to buy your courses even if I don't need them at that point.

[@realpars]

Amazing compliment, many thanks!

[@bmtamer77]

In the past year I have seen many Hvac videos. This is by far one of the best channels I subscribed to. I promise to share with some of my school mates. Thank you sir! Respect and keep the knowledge flowing on a high pressure gauge!

[@realpars]

Thanks for sharing!

[@iliapopovich]

Very well explained in American-English, recently I did a L3 PLC programming in UK and it was horrible. Anyway, I took the certification...And by the way regarding the contactors and relays, you can always put three relays instead of a contactor for some small motors temporarily, just check the ampers. I have an Arduino controller with 230v 10A ,very small relays working even on 3.3v DC, so with them, I can easily switch On/Off a 1000W , 450V motor.

[@aryanrathi4876]

What if only one phase trips? Wouldn't that cause phase imbalance?

[@clenlima]

Thank you! I'm from Brazil.

[@realpars]

Our pleasure!

[@Sanjay.M.Pillay]

I am in industrial automation domain from last 2 years and have referred many videos. But the quality and vibrancy of Realpars videos us exceptional ❤

[@realpars]

Thank you so much!

[@od1351]

These videos are great,although you can be in maintenance field for many years it’s always some details and concepts you may miss but going back and studying and just doing a little research clears up a lot of the fog that can be in you’re head about certain things

[@realpars]

Thank you very much! We're very happy to hear that.

[@daruscole1586]

I Praise God and thank those who have designed and worked on (and may continue to do so) such things as this to make things safer and to help prevent damage to other things. I imagine that some or all of the specifics to the design of such things may have required much work and testing. God Bless them.

[@astrono_mee]

Amazingly simple and interactive way of explaining.

[@realpars]

Glad it was helpful!

[@linetyo8769]

I'm very appreciated that you did this video. It's very helpful. I got the power & courage again. Thank you. I'll keep studying.

[@realpars]

Glad to hear that! You're very welcome.

[@spacexnix]

this video explained the essence to me more than anything existing on KZbin

[@realpars]

That's amazing to read! Thank you so much for your kind support

[@ashutoshsawant7013]

I have been waiting for contactor vs relay video since long. Thank you for this.

[@realpars]

Glad to hear that! You're very welcome.

[@sajadgul]

Great explanation. Hat's off..

[@realpars]

Glad you liked it!

[@ekhlaskhan1356]

I am from Bangladesh and EEE engineer.ur video helps me a lot

[@realpars]

Glad to hear that! Happy learning

[@dmj777]

What an excellent explanation of how a contact operates!🤩

[@realpars]

Thank you very much!

[@katuraysalad]

Thank you very much for this video

[@realpars]

Glad it was helpful! You're very welcome

[@gilbertocastrosustaita6307]

Amazing explanation!!!!very nice channel

[@realpars]

Thank you so much, Gilberto!

[@ricardogarcia3900]

Great video. Remember one thing. You must connect a thermal relay in series between the outputs of the contactor and the inputs of the motor, plus the output that indicates a overload as a signal to PLC.

[@miguelzavaleta1911]

At that point why not just use a VFD instead?

[@Cleofizoid]

...and now you have a motor starter and not a "contactor".

[@rico2207]

Perfect animation

[@realpars]

Thank you!

[@PeterKiiru-x8z]

Well thought out clear and concise presentation thanks very much

[@realpars]

Glad it was helpful! You're very welcome.

[@Xaerorazor0]

If I remember correctly, contactors use a bar across two contacts per line where it can split the voltage to prevent arcing, whereas a relay uses only one point where it will experience the full voltage drop across the contacts, when opening the circuit, so a relay will take damage when opening a higher voltage/higher current source when the contactor is designed to split the voltage across the 2 contacts and reduce possible damage from arcing.

[@sjholmesbrown]

This is correct. The contacts in a contactor are also larger than a small relay and have contact surfaces designed for higher currents. Often the contacts in a contactor will also 'wipe' or rub across each other slightly as they close, this serves to clean off slight oxidation traces and keep the contacts fresh.

[@danielfranchette5547]

the double breaking does not cancel the electric arc but helps to extinguish it, which will define the breaking capacity of the contactor. Much of the complexity of contactor design lies in implementing different arc breaking techniques in a minimal amount of space. it is this electric arc which determines the electrical life of the contactor (because of the progressive degradation of the contacts) which is much less than its mechanical life which is often around ten million operations. The electrical life depends on the type of load supplied by the contactor. An inductive load will generate larger arcs than a resistive load and decrease the longevity of the poles. The contactor manufacturer gives life curves as a function of use to provide for the replacement of devices.

[@tiagogamas7990]

Excellent video by RealPars!

[@realpars]

Thank you very much!

[@thomas8230]

Why did I only come across your channel now? Very well explained. Thanks

[@realpars]

Glad it was helpful! Thank you very much

[@АнтонКвасов-б1л]

RealPars you best! Real learn videos! Thanks!

[@realpars]

Glad you like them!

[@jelynmahinay]

very well explain. thank you sir.

[@realpars]

Glad you liked it!

[@QuestionableAdviser_]

When a YT video explains much more clearer than my Engineer Teacher.

[@shreyashsb5389]

I'm very confused about those,now I'm cleared. thank you

[@realpars]

Glad to hear that this video course helped you clear out the confusion. Happy learning and keep up the learning curve :)

[@amadorcastro8497]

Thank you soo much you help me a lot

[@realpars]

We're so glad!

[@travelthesoul]

Best video ever

[@realpars]

Thank you so much!

[@natesansrinivasan2590]

This channel is really damn helpful for technician and engineers working in industries..

[@realpars]

We're very happy to hear that, Natesan! Always feel free to leave us your questions if anything is unclear. Thanks a million for your support!

[@oficinadoeletricista]

Exceptional full scope of the content on the blog about the information about the contactors. Congratulations on your exquisite work.

[@realpars]

Many thanks!

[@xxcrazymanxx1001]

Thank you so much for making this video I'm just starting my career in this feild and this video was very simple and helpful

[@realpars]

Glad it was helpful!

[@nadjibbenalouache738]

Thank you

[@realpars]

You're very welcome!

[@RiaziMohandesi]

Very simple and understandable explanation thank you realpArs

[@realpars]

Glad to hear that, Ahmad! Happy learning

[@eugenepohjola258]

Howdy. Nice basic knowledge. However. I would be reluctant to connect a contactor coil directly to a PLC output. I would use a relay in between. Also a backfire or free-wheeling diode over the contactor coil is mandatory with DC. There is a lot of induction in the contactor coil when engaged. This energy will rapidly burn the relay or PLC card contacts if not managed. With AC the backfiring problem is not as big but some backfire managing is still necessary by a suitable RC filter over the coil. Typical values are R = 100 ohm and C = 100 nF 500 V in series. Regards.

[@realpars]

Thanks for sharing your knowledge and experience with us! We always appreciate such comments.

[@eugenepohjola258]

@Mindaugas Vaitiekūnas Yes. The backfire diode is a good solution in most cases. It is sometimes experienced that the contactor disegages too slowly as the back current takes too long to dissipate in the coil and the diode. A solution to this may be to use, say, 7 diodes in series. This will force the back induction to rise to about 5 V and provide a faster dissipation. The output transistor will see a voltage of 24 V + 5 V, or some 30 V but it will most likely tolerate that. One could consider using a regular diode and a 5 V zenerdiode in anti series but it is not recommended. Zener diodes are slow and will allow the build-up of a high spike before going into conduction. For the same reason Schottky diodes cannot be used. Regards.

[@kasondensofwa4184]

Very lucid and audible, your videos are the best. How I wish you could have established a training center in Africa for hands on training 🤷🤷🤦 Kindly also do a video on electronic modules 🙏🙏

[@realpars]

Thanks for your kind comment, Kasonde! I will happily pass your topic suggestion on to our course developers.

[@Bonejone213]

Love this channel

[@realpars]

Thank you!

[@billmichae]

The very best video on this topic!

[@realpars]

Thanks a lot, Bill!

[@cep5618]

Excelent clear information. Congrat!

[@realpars]

Glad you enjoyed it!

[@joefanningartist]

Brilliant, very clearly explained, and very good visuals, thank you sir

[@realpars]

Glad it was helpful!

[@Logicmart5754]

Hats off to you RealPars. What a nice way of explanation!

[@realpars]

Thanks a ton!

[@surendhar....]

Best experience

[@electricaltalent7385]

Very well explained I saw it many times easily understood thank you so much for this information..

[@realpars]

Glad to hear that! Thanks for your support

[@sbmtech8920]

Now am clearly understand about contractor and relay thank u realparas

[@realpars]

Glad it helped!

[@ernestoterrazas1132]

Hi! I really like your videos, congratulations for the excellent manner in which they are presented. They are an excellent training resource! One question: I keep seeing in your videos that you mention a -24V DC connection when in reality it should be 0V (M in schematics). When you say +24V in the positive connection, and then -24V in what should be the 0V (M), it gives the wrong impression of a net 48V potential across the supply of the contactor coil. I've seen other of your videos that also have this mistake (not exactly of contactors by the way). Am I missing something?

[@realpars]

No, you are not missing anything. Having designed and installed hundreds of panels over my career, I have seen a few different ways to identify the negative, or common, connection for 24VDC circuits. Technically, the return leg, or more negative connection, in a 24VDC circuit is identified as 0V, earth potential, or COMMON. However, some like to identify the common terminal as the (-) terminal or the negative terminal of the 24VDC circuit (-24VDC). This designation is designed to separate it from other grounds or earth potentials.

[@Cleofizoid]

I always say "DC Common" or "DCC".

[@cheoksc2231]

Really good video explaining things clearly and easy to understand. Many thanks.

[@realpars]

Glad it was helpful!

[@themuddyrug55]

Very informative video, and you explained everything with no way to misinterpret the information. Very nice!

[@realpars]

Glad you enjoyed it!

[@user-ob7eb5sh5w]

Thanks you a lot

[@realpars]

You are welcome!

[@sjholmesbrown]

A small correction for you. You stated a couple of times that most contactors use 24VDC for their coil. While these are used, the great majority I have seen in industry use 120-400VAC for their coil, with an interposing relay to convert the PLC's 24V output to a high voltage AC output for the contactor coil. I also would not directly connect a PLC output to a contactor unless they were specifically rated for it, as they are an inductive load and can generate large voltage spikes when turned off.

[@realpars]

Thanks for sharing that, Stephen!

[@annahabanna]

Fantastic intro to the topic! Thank you.

[@realpars]

Glad you liked it!

[@ibimpepple]

Finally my question has been answered This is the best ❤

[@realpars]

Glad to hear that, Ibim! Happy learning

[@gyanamahendrasatapathy530]

Great explanation about contactor

[@realpars]

Glad you liked it!

[@logeshjeeva1231]

Your videos are very useful to learn and I would say that I like the way of teaching through the awe animated videos..Thanks.

[@realpars]

Happy to hear that!

[@yousefalshorafa154]

thx!

[@simozy4475]

Thank you for the great and simple explanation

[@realpars]

You're very welcome! Happy learning

[@hamidaittaleb825]

Wonderful explanation. Thank you so much 👍

[@realpars]

Glad it was helpful!

[@murzanovv]

Perfect explanation

[@realpars]

Glad you liked it

[@sunilthorat.youtube]

My fav KZbin channel. ❤️

[@perrmyint3098]

Clear and great video thank you for sharing your experience.

[@speedbird7587]

Neatly explained, thanks!

[@realpars]

Glad you enjoyed it!

[@255205titel]

Nice introduction with the connection content of PLC, like it!

[@realpars]

Glad you liked it!

[@garokejelian565]

You have a very good way to describe

[@realpars]

Thank you, Garo!

[@SanaataniArvindam]

Clearly understood sir thank you

[@realpars]

Glad to hear that!

[@uzzaluzzal250]

Useful video thanks realpars

[@realpars]

Glad to hear that!

[@ashkanmahouti858]

I’m convinced I just need to be told how things work the caveman style. I have papers on papers explaining how a contractor works. Learned nothing about how it works but the part names. Watched this video for 10 seconds and I already figured it out

[@realpars]

That's an amazing compliment, Ashkan! Thanks a lot for sharing, we are happy to hear that!

[@siddhant14999]

❤ beautiful explanation

[@realpars]

Thank you!

[@kuppilikiran654]

Simply superb sir 🙏🙏

[@realpars]

Thank you, Kuppili!

[@zubairyamin6044]

this is an amazing and awesome video. keep it up sir. thanks for teaching us💖💓

[@realpars]

Thanks for your kind support, Zubair!

[@abdullahmustafawi3165]

It was so helpful, thanks a lot!

[@realpars]

Glad to hear that! Thank you for sharing

[@thewarlordscalling6537]

PLC stands for Programmable Logic Controller. They are industrial computers used to control different electro-mechanical processes for use in manufacturing, plants, or other automation environments.

[@antipolicia1]

Thanks for the great video, I love your channel just wish you did more on AB.

[@realpars]

Thanks for your kind comment and feedback, Lukas! I will happily pass this on to our course developers.

[@dirasalsabila02]

OMG thank you so much, this video is very helpful!!!

[@realpars]

You're so welcome!

[@alayshah6394]

Great Explanation 👍

[@realpars]

Glad it was helpful!

[@prakash4826]

Impeccable teaching, thank you ❤️

[@realpars]

Glad it was helpful!

[@mixme8655]

Wow that's why i like all your videos

[@udithabandara6382]

thank you, well explained

[@realpars]

Glad you liked it! Thank you for sharing

[@sivaramank5016]

@8.10 normally stop switches will be NC..but in this video it is represented As NO

[@realpars]

True, Stop pushbuttons are normally NC contacts. However, for some installations, the START and STOP pushbuttons are both NO contacts brought into a PLC DI card, as in the video. In other installations, a single NO pushbutton is used to both START and STOP a motor. For single machine installations or shop-type installations, NO contacts are sometimes used when the E-STOP is in close proximity in case of failure.

[@SrOsvaldo1]

Thank You Real Pars

[@realpars]

You're very welcome!

[@sanelekabinde625]

Best video ever. Keep up the good work

[@realpars]

Thank you, Sanele!

[@gifarihasyim7776]

This video saved my careers. By the way, I have a question. Does A2 also connect to PLC? If yes, is the voltage connected to A2 have value of -24 V?

[@realpars]

A1 and A2 are the to connections in the contactor that actuate the coil, which in turn pulls in the contactor and allows current to flow from L1/L2/L3 to T1/T2/T3. As the video explained, the PLC I/O cards are not powerful enough to actuate the motor directly, so we use a contactor with a low-voltage coil, in this case a 24VDC coil. A1 is connected to +24VDC at the I/O card (the digital output terminal) and A2 is connected to 24 Common. Sometimes we refer to the common terminal as -24VDC, but it is truly a ground, or 0V potential point that is shared with the power supply. So when the digital output is energized, 24VDC flows to A1, and the coil is energized, pulling in the contactor. A connection to A2 is required to insure a steady 24VDC is applied to the coil (e.g., form a complete circuit).

[@emmanuelflores1781]

Awesome video, great explained!

[@realpars]

Glad you liked it!

[@ac4cars656]

Yes, video has been very helpful!

[@realpars]

Glad it was helpful!

[@maruthiprasad8184]

Thank you very much for valuable information. Kindly make a video on Different PLC programming languages available and their applications and their best uses. Thank you very much for taking the feedback and making the same.

[@realpars]

Hi Maruthi! Thanks for your comment and your suggestion. I will pass this on to our course developers! Thanks for sharing and happy learning!

[@anilkumar-yf9gb]

very nice explanation. can you explain in detail about operation(working) of vacuum circuit breakers

[@realpars]

Thanks for your comment! I will happily go ahead and pass this on to our course developers as a topic suggestion. Happy learning!

[@xuanminhtran8547]

I realy love your videos, they are very helpful.

[@realpars]

Thanks a lot, Xuan!

[@deepensharma7977]

Such a helpful video.

[@realpars]

Glad to hear that!

[@marcorodriguez6811]

beatiful and helpful... you have a new suscriber

[@realpars]

Awesome, thank you!

[@nsjx]

really Appreciate the Basics 👋

[@realpars]

Glad you like them!

[@Framwerks]

Thanks very helpful 😊

[@realpars]

Glad it was helpful! You're very welcome

[@cletusasiwoko2368]

Hello Real Pars, I enjoy watching your videos. Undoubtedly, I have learnt a lot through them. I have a request. Can you please make a video on phase monitoring relay? I'm having a challenge understanding it. Thank you

[@realpars]

Great suggestion, Cletus! I will happily pass this on to our course developers. Thanks for sharing and happy learning!

[@azharvoice440]

Awesome... Excellent work❤

[@realpars]

Thank you so much!

[@surendrakverma555]

Very good. Thanks 🙏

[@realpars]

You're very welcome!

[@lovesophia19]

I love this channel.

[@realpars]

Glad to hear that, Lola!

[@shabsck9609]

Good explanation..keep going..thanks alot❤️❤️

[@realpars]

Thanks a lot!

[@SOKHA847]

Thank for your video❤

[@realpars]

You're very welcome!

[@royfamily865]

Thank you very much, i like this video

[@MiRac_Oje]

Very helpful 💯💯

[@realpars]

Glad to hear that, happy learning!