TESTING ZE - TNCS - TNS - TT - WHAT ARE THE DIFFERENCES BETWEEN THE EARTHING SYSTEMS
In this video from Learn Electrics, we will look at the differences between the common earthing systems, the things that you need to know when testing ZE. Although the testing of ZE is similar in each case, as we have shown in previous videos, there are physical differences between these systems: and it does affect the earth path for fault currents.
Some of the more frequent questions that we have been asked have included …
What is Ze?
Which part of an electrical system is Ze and which part is Zs
Why is Ze so very different in TT systems and is Ze different between TN-C-S and TNS systems?
In fact, what is a TNCS system
So in this video we will address these questions
To view all of our videos type in LearnElectrics all one word into the KZhead search bar.
This is video No.166 on our KZhead channel where we have videos on a wide range of electrical topics.
Just want to say a huge thanks for this and all of the previous content you've made available. It's been no end of help to me whilst re-training into the electrical industry on the C&G 2357 and 2391. Brilliant reference material explained clearly, it is very much appreciated! Thank you.
That's good to know Gareth and so happy it helped. Never stop learning, its a great trade to be in. Good luck with your future career, go get it! Dave.
I’ve always had an idea of TNS and TNCS but not TT, thank you learn electrics!
That's great that you've found it useful. Thanks for watching Smoovy, appreciated.
Not even 6am on a monday and they uploaded a video. That's devotion ;)
Thanks Richie, thanks for the support. Dave.
Great videos, I'm working through them one by one and finding them a huge help. Thank you 👍
Glad you like them John, lots more to come. Dave.
Thank you for sharing. Your video's are always welcome. 👍🏼
That's good to know Phil. Thanks for supporting the channel. Dave.
Another first rate teaching video! Thanks
Very welcome Alan, thanks for the support. Dave.
You nailed on my doubts Dave, thanks again
Glad it was useful, thanks for watching the channel.
Always excellent explanations thank you.
Glad you like them and thanks for the feedback, appreciated.
Brilliantly explained.
Glad you liked it Denis and thanks for the feedback. Dave.
The Best lessons electrical, thanks.
Glad you think so, much appreciated. Thanks for watching.
Brilliant video nice and clear, great pace...
Thank you Christopher and thanks for watching. Great feedback. Dave.
Always great lesson
Glad you think so Michael, much appreciated.
Your video is very informative and better than paid courses
Nice of you to say that, thanks. Very much appreciated.
Fantastic video!!! Brilliant!
Many thanks, glad you enjoyed it. Dave.
Thank you for sharing the video.
My pleasure, thanks for watching.
Excellent 👍
Glad it was useful, thank you.
Excellent explanation
Glad it was helpful, thank you.
Great video
Thank you Mr D. Much appreciated support.
It's fun to watch these, since TT aren't allowed in Sweden where I live, and unless the building is from the early 50's or older, all houses regardless of there use are 3 phase here, a normal house hold have 3 x 16 Amp fuses, since we never use single phase anymore and haven't done so for some 60+ years here. Most have TN-C too the meter and then we make them TN-C-S inside the houses. Greetings from Sweden 😁
Thanks for the info and thanks for watching. Dave.
The solder blob picture at 10:36 to me looks like a tncs system as the supply cable is combinig the two and then it sepeartes at the earth bar. Im sure ive misunderstood somehow? I appreciate your videos, ive learned so much.
Trust me, its a TNS and the best clue to identifying TNS systems. But its good to question. Thanks for watching. Dave.
Nice one dave another brilliant video 👍👍 can I ask, maybe a silly question but what happens if the Ze is well over maximum value (does it ever happen) do you just notify the dno and leave it with them .cheers dave 👍
Its never happened to me but yes, we should notify them because our own work won't pass the tests. I know of one sparky who contacted them, told them the customer was in danger and they were there in an hour, Dave.
@@learnelectrics4402 cheers dave good to know 🙌🏻🙌🏻 not sure if you have done one yet but will you be able to do a video on multi function testers functions 2 lead high etc especially a merger as that’s one I’ll probably invest in when the time comes 👍👍
We had a TT system in our house in Cambs (overhead supply). The earth was bonded to the copper water pipes instead of an earth rod. Problem was, the incoming water (and gas) pipes were plastic. With a typical collection of appliances connected up, there was enough leakage current to earth to give a fine belt when touching the taps. It now has a proper 1m long ground rod.
Yes, some of the old methods left a lot to be desired. I stopped in a chalet on a remote Scottish island that was like that. Thanks for watching. Dave.
Thanks so much
You're welcome, thanks for watching.
Absolutely Love Learn Electrics explanations. But audio is often awful!
Thanks for the feedback Kevin, I do take it seriously. I've listened to this video on the laptop, on the ipad and on my Samsung phone and cannot find a problem with it. I know a couple of folk have said the audio is bad and over this year I've tried two new microphones (expensive ones) and a new laptop. I've also tried listening on two different sets of headphones but still can;t get bad audio. I've tried to resolve it Kevin, but can't find a problem. Thanks again for the feedback and for supporting the channel, appreciated. Dave.
@@learnelectrics4402 Thanks Dave for investigating audio quality, probably a Gremlin, I am listening on a n iPad with apple headphones & listen to various you tube videos after each other & this one was quite bad audio wise, won’t stop me listening to you as your explanations are superb. I should have retired last year but still love what I do. Never too old learn in my experience.
Love your vids. I’m currently studying.. please could you do a video explaining how neutral and earth are connected together yet no current flows back on the earth and down all your cpc’s? I don’t understand how earth and neutral are connected together and also I don’t get how current can flow through the ground in a TT to disconnect when soil is an insulator Thanks
Thanks Jake. Watch the video again, it tells you what happens to the fault current in a TT system.
Thanks 🙏
You’re welcome Taha. Dave.
This channel is so good! I learn a lot about electrics with every your video! But please - buy a better microphone or just adjust current one.
I've tried a new mic and now I'm on a new laptop so let's see. Thanks for watching. Dave.
What if we have TT like in the video but we also combine neutral and earth in the meter? I think that's what we have here, in fact the earth and neutral terminals in the meter are linked by design. I used a multimeter to confirm the continuity between both terminals of the new meter (uninstalled).
In the UK there are only Line and Neutral connections in the meter. Thanks for watching. Dave.
Most pple in my country use TNC. S but with earth rod on building . So in case of fault which path does the fault current use back to the transformer, neutral or earth rod then to soil upto transformer
The fault current will share itself along both routes according to the conductance, so most will flow along the metallic neutral/Earth. The earth rod could be there to balance any potential differences around the building. Thanks for watching. Appreciated.
Thank you
I NEED HELP, I need to understand why and how, in a fault the cpc becomes live and takes current to the transformer and due to the lower resistance there is an imbalance in the neutral/Live so the breakers trip, THATS WHAT IVE BEEN TOLD, doesn’t make sense because if the cpc cable is smaller in size there would be more resistance not less right? And how would that affect the breakers, does the mechanism in breakers trip become the neutral does not have a return path or something else
Have a look at these videos. the answer lies in the loop impedance. The LearnElectrics.com website also has a search box to find videos on specific topics. kzhead.info/sun/dJ2TqslsrICdha8/bejne.html and kzhead.info/sun/hLurXc2kqIlsank/bejne.html
Also what is an IT system ? Could you do a video please Thanks
IT is an insulated earth system and a specialised earthing system.
What do you call the earthing system in metro Manila where two hots/phases(L1&L2) and PE is going through to the CU?
These videos are aligned to the UK Wiring Regulations. Much of the information is also relevant to electrics elsewhere but not every situation can be covered by them. Thanks for watching though, appreciated.
Do you know sir European country doing this L1,L2 + PE? Thnx
Sir, you missed earth symbol at transformer neutral point I tns and tncs system.
Thanks for watching, appreciated.
👍
Thanks for watching Brian. Always appreciate good feedback. Dave.
There should be an isolator in that meter box
Thanks for the info Tony, appreciated.
In the UK, if a home has a whole house RCD, is it likely the home is on a TT system? Or, are whole house RCD's implemented so widely, one can't make any inference about the underlying earthing system?
Nowadays, it can be any earthing system as RCD devices have become so common and the prices have dropped. All new domestic installations now will have RCDs for all circuits. Once you learn how to recognise the different systems, you don't forget. Hope this helps.
@@learnelectrics4402 Thanks, your video helped to clarify my past understanding. I live across the pond in Canada, where TNCS dominates. When we visit our daughter north of London, I've often wondered what system they are using in the old British country home they live in now.
The narrator sounds very much like my old tech college teacher John West 🤔 brings back memories, he was a great teacher in simplifying electrical installation & theory
voice is overloading the mic resulting in very distorted audio This is very common when no broadcasting experts are employed
Only recently has this overload been apparent. Dave might have a new microphone?
I've not got a studio Les but thanks for the info. Dave.
Thanks Mike. I've just got a new lap top, the old one was starting to play up (it was 12 years old). That might have been part of the problem. Thanks for the support.
@@learnelectrics4402 It was about 6-8 weeks ago that I noticed some distortion on your narrative. Prior to that it was very clear. With digital stuff you don’t want to peak at 0dB like analogue, better to peak around -20dB if you have a means of monitoring your audio level.
Employ a broadcast expert? Are you having a laugh? Yes it’s a bit grainy but is fully comprehensible and is full of decent content!
Hi Dave ,is it common to convert an existing TNS to a TNCS TO upgrade the earthing and how is it done without removing the TNS Part of the system pls.Big Thank you.
This is something you need to discuss with your supplier as this will require changing the supplier's cables. Thanks for watching. Dave.