Zs - TABULATED or MEASURED. An easy method to calculate the Zs values without the books.

[@learnelectrics4402]

To go directly to our LearnElectrics Channel on KZbin Click on the link below … kzbin.info/door/YaJQnpO4XAp0yCgqzMkmfA

[@no_short_circuit]

Thanks for the video. As I've said before, I'm not qualified but still learning. I watched your other video on "35" and was helping a mate of mine who is an electrician and he couldn't believe that "it actually works!" and he's been a sparky for 30 years.

[@learnelectrics4402]

There we go. You are now a Wizard in his eyes. It's the little memory joggers that make the job so much easier, especially for folks that are learning 18th Edition. Stick with it, it is a great trade to be in at any age, it's taken me all around the world over the last 40 years. The most important thing is your attitude towards learning. If you want to learn, you will. Keep going, good luck, Dave.

[@abdirizakhassan1073]

Dave is brilliant teacher/mentor. He explains topics extremely well and breaks down things in order for you to understand easily.

[@learnelectrics4402]

Thank you Abdirizak. I really appreciate your comments. Dave.

[@saxocoustic]

Thanks very much, listened to your videos to help with my 2391 online exam resit, passed this morning after anxious revision at 5am headphones on studying your KZbin posts- appreciate you sharing this information, regards Paul

[@learnelectrics4402]

Fantastic news. So glad you passed. If the channel helped you, then please spread the word and help others to pass. Keep learning. Dave.

[@StreamFeeds]

Love these videos so much… really working wonders with my training. I’ve subscribed. Keep up the good work mate! Whoever you are! You’re a great teacher!

[@learnelectrics4402]

Brilliant feedback, thank you so much. Dave.

[@ImWreck]

i was really struggling with zs measured and tabulated until i saw these videos. thanks for all your help, i have my 2391-52 next week so will update!

[@learnelectrics4402]

Glad it is useful and good luck. Dave.

[@persian_warrior1]

Thank you for very easy and simple way to explain electrical. Many many thanks 😊 🙏

[@learnelectrics4402]

You are very welcome Amir. Thanks for watching. Dave.

[@justinHTE84]

Probably the most useful KZbin video any electrician could watch! Any chance of some more 2391 related videos please 🙏🏻

[@learnelectrics4402]

Certainly Justin. I try an make the Thursday videos relevant to exams, calculations etc. keep watching, lots to come. Dave.

[@angelofranklin1]

Super and very well explained thank you, to date i think i have watched all your vids. All very good.

[@learnelectrics4402]

Thanks Angelo, your support is really appreciated. Dave.

[@davidpatterson1574]

Thanks Dave. Excellent presentation.

[@learnelectrics4402]

Thank you David, much appreciated comments and glad that they are useful. Dave.

[@malachygallagher4936]

Brillent as usual! Regards mg.

[@learnelectrics4402]

Thanks for the ongoing support Malachy, really appreciated. Dave.

[@Dibbo1979]

Great video once again mate👍🏻

[@learnelectrics4402]

Thanks Dibbo, appreciated. Dave.

[@dineshmakwana1890]

Super very well explained. Thanks you so much.

[@learnelectrics4402]

Thank you Dinesh, trying our best. Thanks for watching. Dave.

[@azizurrahman6663]

Hi Dave thank you very much very nice , please do more video it very helpful

[@learnelectrics4402]

Absolutely will Azizur. Next weeks video is about fault finding on a socket ring circuit. Thanks for watching, thanks for your support. Dave.

[@kevinpearson4505]

This is fantastic! Thank you very much.

[@learnelectrics4402]

If it helps, great. Thanks for the positive comments. Dave.

[@paulhayles6947]

Dave-work of genius.. super well explained-as usual. Do you have any quick methods for working out the maximum demand?

[@learnelectrics4402]

Paul, no magic numbers but have a look at the video shown below. Max demand is very easy to work out and the video takes you through several different scenarios. Dave See Diversity and Maximum Demand on this link ... kzbin.info/www/bejne/ioeVeo2qot6Xo5Y

[@razomar-cs7wv]

Thanks very much.

[@learnelectrics4402]

You are very welcome. Appreciated.

[@michaelwaheeb4998]

Very helpful 👍👍👍

[@learnelectrics4402]

Thanks Michael. I appreciate your helpful comments. Thanks for watching. Dave.

[@Ibrahim-vt2tz]

Thank you ❤

[@learnelectrics4402]

Appreciated. Thanks for watching.

[@ahmedalazazi2895]

Wonderful

[@learnelectrics4402]

Thanks for the comment and thanks for watching. Dave.

[@jonanders76]

Hey agree, this is a way of calculating Zs but in my opinion it doesn’t give you an understanding of the whole thing and how its actually. Calculated in BS7671. Which isn’t that much more complicated. All thats needed is 3 to 5 x In for B types, 5 to 10 for C types and 10 to 20 for D types. This allows you to understand that a breaker has a range it must trip within. As we’re looking for a worst case for maximum Zs you use the higher value. Eg 32A MCB B type would be 32 x 5 = 160A. Using Ohms law 230V / 160A =1.4375ohms. Using 0.95 correction for voltage fluctuation Cm 1.4375 x 0.95 = 1.37 ohms. Simple

[@learnelectrics4402]

Thanks Jon, yes, we already have a video on how it is calculated from the time and current tables and this is another interesting method. Thanks for watching, thanks for your input. Dave.

[@2194jamie]

Why bother when shorter and easier method .

[@brianhewitt8618]

brilliant, thankyou

[@learnelectrics4402]

Thanks Brian, thank you for watching. Dave.

[@rickys9357]

Hi dave I've been watching your videos for some time now they're very useful but one thing I'm struggling with the difference of the Max Zs tables of 0.4s and 5s disconnection time, if you could explain that'd be great help and much appreciated thank you.

[@learnelectrics4402]

Ricky have a look at this video about final (0.4s) and distribution (5s) circuits kzbin.info/www/bejne/gKTUqWqYbruXr68 Note that this has the old website address on it (dot co dot uk) which is now a dot com address. Another video on final/distribution circuits is planned for the near future too. Watch this space. Dave.

[@razomar-cs7wv]

Hi I am doing 2392 on line goal exam, any things special I should know about it?

[@learnelectrics4402]

Just practice lots of questions, a few every day. Actually write the question and write the answer. make sure you are good on calculations. Have a look at thie video below. also go to LearnElectrics.com and put 2391 or Amendment 2 into the search box. Loads of videos with questions and answers in the exam style. Good luck. kzbin.info/www/bejne/fHq8gamHoJpohKM

[@persian_warrior1]

Hi Guys Have you got any book or would you publish a mini book yo carry in pocket, simple as you explain on KZbin? It would be fantastic idea for many learners or even professionals

[@learnelectrics4402]

Amir, great idea. one or two others have asked, perhaps I should consider it, if it would sell.

[@THECARKUS]

Thanks for another excellent video.

[@learnelectrics4402]

Thank you Mark, appreciated comments. Dave.

[@learnelectrics4402]

My pleasure Mark.

[@JACKSPARK291]

Boss

[@learnelectrics4402]

Thank you Jack, thanks for watching.