CIRCUIT BREAKER TYPES - How they work and inrush currents

[@learnelectrics4402]

SEE ALL VIDEOS - To view a list of all our LearnElectrics videos, click on the link below. There are many videos on many electrical topics including Installation, Part P, 18th Edition, Testing, Certification, Lighting, Sockets, Ring Circuits and much more. kzbin.info/door/YaJQnpO4XAp0yCgqzMkmfA

[@asadng2920]

The explanation is at the Highest level of standards and second to none. Thank you Sir.

[@learnelectrics4402]

Thank you Asad, brilliant feedback, really appreciated. Dave.

[@kevinconstantine5244]

Thanks again for the really useful information on circuit breakers. You've become my little "Go To" for electrical help, advice and clarity when im carrying out little projects now my dad has passed. Really appreciate your videos. Good work.

[@learnelectrics4402]

Thanks Kevin, really appreciate the feedback. Yes, my dad was always at the end of the phone when I needed him.

[@AngelaPeters-fy1tc]

WOW! such a well explained simple to understand video. I had trouble knowing exactly what inrush currents were and also examples. Its not that I didnt know as the name is self explanetary as in inrush ie higher than normal but you just hammer it home into my cerebellum with your drawings and explanations. Keep up the excellent work Dave, Im determined to learn this trade by hook or by crook.

[@learnelectrics4402]

Glad it was helpful and stick with it. Keep learning, a little every day, it is a good trade to be in and has taken me aroiund the world several times. There is always work for electricians. Dave.

[@alancooper7018]

Best video I have seen on the subject. Thank you.

[@learnelectrics4402]

Thanks Alan. Really appreciated, gives me encouragement to make more. Dave.

[@olly7673]

Your tutorials are excellent, both with the visuals and the explanation of theory, please keep them coming. I don't know if you have covered this in a previous tutorial and I missed it but the use of different types of protective device to accomplish selectivity from cascading along different distribution circuits would be welcomed. In domestic scenarios where the main DB feeds a garage DB, which then feeds a shed at the end of the garden for example.

[@learnelectrics4402]

Olly, great feedback. No, not covered that yet - it's called discrimination and will be covered in the next week or two. It will be on MCBs, RCBOs and RCDs etc. It's a good topic. Thanks. Dave.

[@user-qi8tv2sj4m]

Great video. Learning lots watching this. I will pas this in at college.

[@learnelectrics4402]

Please do spread the word, thankyou.

[@kint5ugee]

This is exactly the information i was looking for. I had been wondering if my LED lights had a high enough inrush current to trip the 5 amp MCB but it seems it allows for the inrush.

[@learnelectrics4402]

So glad we could help. Lots more videos to come. Thanks for watching. Dave.

[@patrikprekop8975]

Great videos. I do follow you and I gain my knowledge with every video. Thank you!

[@learnelectrics4402]

That's great to hear Patrik. Every little bit of learning adds up over time.

[@paulhayles6947]

Another super well explained video.

[@learnelectrics4402]

Thanks Paul, I really appreciate your comments. Dave.

[@matthewfewings6023]

Fair play although I know most of the content of your videos, every time I watch one, the visuals help reaffirm why the knowledge is so important. Would love if you did an on site guide video explaining as above. Top video once again.

[@learnelectrics4402]

Thank you Mathew. Very true words, we should all keep learning and refreshing our knowledge. Great feedback, appreciated. I have made a note of your request and it will be actioned in the near future. Dave.

[@matthewfewings6023]

@@learnelectrics4402 hi Dave, please don’t do it on my account. I just really enjoy some of your 18th edition wiring regs ones and whilst watching them thought to myself I wonder how many important things in the on-site guide I don’t realise how or why they are so important. You are spot on continued personal development by continuing to understand the basics. 👍

[@learnelectrics4402]

Yes Mathew, the On-Site guide will be covered too. Thanks for taking an interest in the channel. Dave.

[@gbelectricks]

Great explanation Dave, thanks👍

[@learnelectrics4402]

Thank you very much. Glad you found it useful. Dave.

[@esmeewen]

Thanks for the information, visual helps a lot

[@learnelectrics4402]

Thank you. Great feedback. Dave.

[@chrisgibson5803]

All videos have the best explanations possible. Even above the e5 group guys. Can you do one on design please.

[@learnelectrics4402]

Thanks Chris, yes, Circuit design videos are being considered. Dave.

[@learnelectrics4402]

I wondered and now I've put it onto the list. Thanks for watching. Dave.

[@learnelectrics4402]

Chris, this has only just popped up on my screen (Aug 2024)

[@azizullahkhan7888]

Thanks for uploading

[@learnelectrics4402]

My pleasure, glad you enjoyed it and thanks for watching. Dave.

[@rimasp4769]

Great video

[@learnelectrics4402]

Thanks for watching. Dave.

[@olavogazzola2650]

What a great video!

[@learnelectrics4402]

Thanks for the fantastic comment. So glad you enjoyed it. Dave.

[@cygnus108]

Great explanation..Thank you...

[@learnelectrics4402]

Thank you Alex. Glad you found it useful. Dave.

[@curentarul]

Great video! At B type, in that table, it is mentioned that it is for long cables. I guess because it has to do with a bigger Zs and a low PFC?

[@learnelectrics4402]

Longer cables mean higher resistance/impedance that C and D types might not meet. But if you can install a smaller size MCB say from 32A to 20A, you're permitted Zs increases. Thanks for watching. Dave.

[@curentarul]

@@learnelectrics4402 Thank you for your answer! Have a great day!

[@roystonpereira2887]

Great video, thank you👍

[@learnelectrics4402]

Thanks Royston, your comments are appreciated. Dave.

[@ibrahimabdullah4430]

🙏 thank you 😊

[@learnelectrics4402]

You’re welcome Ibrahim, Dave.

[@paborlouise319]

Thanks a lot for this.

[@learnelectrics4402]

Glad we could help. Thanks. Dave.

[@ja_adam_]

Hi.. would you be able to do a video on what io , ir etc mean on an MCCB and why you would want to adjust them. Instead of adjusting why would you not just get the correct one

[@learnelectrics4402]

Good idea Jake, it's on the list.

[@ahmedalazazi2895]

Great job Can you please clarify if there is an earth fault, which one will trip first the MCB or the RCD Best regards

[@learnelectrics4402]

If its a 30mA RCD, usually the RCD will trip first. Hope this helps.

[@ahmedalazazi2895]

Many thanks to you May I ask you a question I have some lg air conditioning units equipped with inverters Do I need to replace the type A RCD with type B

[@andrewforsyth4799]

Thanks again

[@learnelectrics4402]

Thank you too, Dave.

[@sammaimas155]

Sorry, I am a newbie to this subject but was drawn to it when researching what fuse size to use on an offgrid solar setup. If a 10 Amp fuse will not blow until it might reach 100 Amps, then what cable size should I be using, something that is rated for greater than 10 Amps or a cable rated higher closer to 100 Amps???

[@learnelectrics4402]

Its all to do with how long it takes to trip. Have a look at this video on the link below. It will help. thanks for watching and stick with it, its a good trade to be in. Dave. kzbin.info/www/bejne/jKW3hp6LpbZgiMU

[@lllCANDYMAANlll]

What does I2 (current causing effective operation of the overload) mean? is it when it arcs temporarily and raises more amps?

[@learnelectrics4402]

Its the current required to cause the device to operate within 0.4 seconds. In other words, the current required to satisfy the Zs tables. Have a look at this video, it shows how I2 is used to calculate ZS. kzbin.info/www/bejne/f5vTe35nmq9_sNk

[@lllCANDYMAANlll]

@@learnelectrics4402 Thanks again dude!

[@victortancheongwee]

It is normal for main circuit breaker to be a little hot at time? Mine once in a while trip, I dont think my appliance is shorted as it could be reset. I think maybe it is too old, mine house is 25 yrs old, Ty

[@learnelectrics4402]

At 25 years you may need a Periodic Inspection by a competent electrical inspector.

[@leestorey18]

Does the thermal overload still work in a TT system?

[@learnelectrics4402]

Unless you can get enough current flowing to exceed the breaker rating by enough amps and enough time, then no. That's the problem with TT. If the fault current flowing in say a 32A circuit is less than 32A then it will never trip. Good question. Thanks for watching. Dave.

[@Rossisearle]

MCB provide earth fault protection??

[@learnelectrics4402]

Correct. Thanks for watching.

[@amarnathsathiyamurthi6239]

Why this MCB takes 15 mins to trip for 52 amps in a 32 amps MCB type B ? Can you please explain

[@learnelectrics4402]

Have a look at the video again Amarnath. We explain in the video just why and also look at page 370 in the Regs book for Type B breakers. The table shows a trip time of 900 seconds for a 32A breaker if there is only 52A of fault current. 900 seconds is 15 minutes. Thanks for watching. Dave.

[@adammiddleton3362]

There is a difference between TPN and 3P+N.

[@learnelectrics4402]

Yes there is. Thanks for watching. Dave.

[@paborlouise319]

Thanks alot for this. I just had to refresh my mental toolbox 🧰 🔧

[@learnelectrics4402]

Great, thanks for watching Pabor.

[@ifyougetstucklookitup237]

Thank you for your efforts.

[@learnelectrics4402]

We try, we do try. Thanks for watching, it is appreciated. Dave.