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. ruclips.net/channel/UCYaJQnpO4XAp0yCgqzMkmfA
This was the most clear & easy to follow video on this subject I have come across. Most channels only show how to test but don't explain clearly or give examples of why we're conducting the test in the first place. As a visual learner I really appreciate the pictures as well. Looking forward to more videos please keep them coming. Thank you.
Well thankyou Riaz, great feedback. So glad we have got something right. Our intention is one topic, one video and properly explained. Really appreciate your comments. Keep watching, lots more to come. Dave.
Great video guys and a must to do just after the plastering. I recently checked a ring final circuit and found the continuity was fine but the Insulation resistance failed. Eventually narrowed it down to a plastered board screw through a cable in a stud wall. Other trades can be your worst enemy, so always check and where possible protect the cabling from potential damage. Test, test, test...
I would like to thank you for the helpful videos that you are making them. Watching them , really helped me to understand more then College. Once again thanks
Thank you Abdul, glad you find the channel helpful. Spread the word, the more that watch, the more videos we can make. lots of good topics on the way. Cheers. Dave.
Hi Dave, can you make a video on how to read electrical installation drawings on building site preferably UK standard. I want to know how to read the measurements on drawings, symbols and how to apply it on site. Thanks
Thank you. Very grateful to you for your excellent explanation. I started the job in corrosion control equipment, and some electrical operations were hard for me. But now I get the point.
I am very exciting of best video presentation . I clear about all testing that you displaying in video presentation . Thanks for sharing your knowledge .
Hallo Sir.Thanks for your video.I would like to ask you if there are measuring devices on the market so can someone identify where exactly on the cable a damaged insulation lies.Thanks a lot and a Happy New Year!
Once again no one explains things better. Thank you! Very easy to follow and retain the knowledge at the end. I recently tested an installation after changing some face plates and light fittings as well as extending some sockets outlets. One of circuits passed the continuity test but failed the insulation resistance test however the RCD has was not tripping although it is mechanically sound. It doesn’t make sense so I am going back to re-test the circuit as I think I must have made a mistake like leaving something plugged in or a bulb or maybe some other mistake I made as I was tired. It would be great if you can do a video on insulation resistance testing at DB, single circuit and whole installation.
Yes, if the IR test fails, always check for things left in circuit. Usually Le and NE pass but LN fail. If its lighting remember to flick a switch and test again. Dave.
Hello, many thanks for your great videos,, in my country most of the old buildings which are more than 10 years old don't have Earth ,, so what is the best way to perform the test while there is no earth conductor in the building?
You can test continuity between the line and neutral conductors and insulation resistance will only be the same, between line and neutral. Thanks for the information, good to know what happens in other countries. Thanks for watching. Dave.
Thanks Tony, you're very welcome. I've also got 18th Edition videos on Thursdays each week. Next weeks is about Zs tables. Spread the word mate. Hope you are well. Dave.
I did an extensive insulation test between a wire and the ground, actually the wall. So I watered the whole wall with water, also above the cables. In case of damage in the wire insulation, there will small cracking sounds coming from the wall, and the resistance will be low. I put water also to easy the conductivity and find possible deffect. Also, I am testing with 1000 volts.
In a CNE system: ? Before insulation testing between neutral and earth of multiple circuits, is it necessary to remove the main incoming earthing cable from the earth bar in the consumer unit ?
Excellent very well explained video in a way that people can understand instead of blinding people by science like some books do also top quality diagrams
Perfect, let's hope all goes well for you. As an assessor, the really important thing with practical assessments is that I want to see you set your meter up correctly before you start testing, otherwise how do you know what is a good reading and what is a bad one. Good luck. Dave.
Your videos are really helping me to understand electricity. Can you please make a video on HOW TO READ ELECTRICAL INSTALLATION DRAWINGS, eg on Building site. Many thanks.
Some of the stages of the PAT inspection’s I used to perform were also similar to this, If someone or Spark rewired their radio/microwave and all was well i.e. correct fuse, polarity and earth pass, visually OK and correct size wire etc it would get a pass. However this seems not to be the case for electricians in domestic installation situations. They don’t seem to happy signing off someone else's work, I would like to ask the reason why? Is this because the test instruments of today are not adequate enough to prove the wiring And therefore do not give them the confidence? Great channel by the way, one of the best out there in my opinion.
Thanks Paul. The point I was making was that if the cooker is only 3 metres from the CU then expect a very low reading - maybe 0.03 ohms - big csa and short run. But if it is a lighting point at the far side of a large house expect a higher reading, maybe 3 or 4 ohms - thin cable long run. It only comes with doing the testing many times. Example, when you get to know your car you can look at the petrol gauge and just know if you have enough petrol to get to work and back or whether to fill up on the way. Hope this helps. Dave. Take a look at our video - Cable length calculations and R1+R2 on this link ruclips.net/video/Qq_9MNH8XxU/видео.html
Great video again thanks very clear. I was wondering if you have any advice on changing career to becoming an electrician? I am currently 45 and was considering doing a course at trade skills 4 you. I realise that the key to making it work is getting some work experience so I am currently trying to find some work experience to go along with the course as I believe this would be vital. I am a musician and have build things like guitar effects and a valve hifi amp and I enjoy learning this stuff. Do you think it can work as I don’t want to waste my money and time ? Thanks Glenn
Chris. Shop very carefully for the right training centre to attend. I always advise people to actually visit at least three centres and have a good look around, look what training material they will use to teach you, the training boards, their facilities and what books and training notes do they supply. For you, you will need a training course with a good mix of practical and theory. Please, check the different centres before parting with what will be thousands of pounds in the long run. You need to be at a centre where you feel comfortable. We don't do classroom teaching any more and we have a policy of not recommending anybody but you would be as well to check out the training from the Part P scheme providers even if it is extra travelling, you will see their logos on most electricians vans. It might cost a little more but going through a scheme provider they will guide you towards registration and they have the highest standards to maintain. Good luck. It is a good trade and 45 is still a baby. Dave.
17:18 continuity test can also detect this fault if the other end of the conductors are open. If there is continuity then the conductors are shorting somewhere behind the wall.
Can I ask a question please. When testing a ring main and they have used the trunking as cpc what do you do for your R1 value and also what do you do for r1+r2 and you can't cross connect? Thank you
Good question Alan. Using the blue 18th Edition Regs book. Regulations 543.2.2 and 543.2.5 apply. Conduit/trunking can be used as a cpc if continuity can be guaranteed. R1 is the Line conductor and R2 will be the trunking. You cannot do a crossover test as such, just connect one end of the trunking to one line and the other end to the other line. Steel is about 12% as conductive as copper but I would imagine your trunking has a csa of much more than 8 times the copper cpc that would normally be used.
@@learnelectrics4402 I never ever thought to do those 2 tests together, I always did one or the other. I was never shown or heard that before, and it makes absolute common sense. I have been baffled sometimes why I couldn't find a fault on an IR test yet the rcd wouldn't turn on. I am truly a lot wiser after watching this video. Great stuff
Some meters are auto starting when they find a connection. Turn it on and put the probes together and see if it responds. Meggers do this amongst others. Every manufacturer does something different. Thanks for watching. Dave.
Another very good lecture Dave. By the way, I like the way you test continuity and I can wait to see the fault finding but it seems like you are doing R1 + R2 and R2 + Rn, if not I can start by doing that. Thank you once more for the well and rich lecture.
Absolutely right Omar. It says at the start of the video that we are treating this as first fix, in other words we have just installed the cables and not yet attached any accessories etc. When the cable is newly installed we should test to confirm that all three cables are good L + N + E. It is no good waiting until all the walls are plastered and the sockets fitted to find that the neutral has a break in it. We are doing another video on testing with accessories installed. Good question and thanks for watching. Dave.
@@learnelectrics4402 I have seen electrician checking their cable before all the boarding is done but still a screw goes in the cable after the plasterboard. So, to be on the safer side, what you meant is , you check before the plaster and after.
Correct Omar. Check at first fix and if all is ok any damage that you find on second fix checks might be caused by the plasterer or carpenter. Who is going to pay for these repairs, the new cable, re-plastering the wall etc. If you don't check all your cables at first fix, how can you prove it is not you fault. For the time it takes to check at each stage it is worth it. Good luck. Dave.
Excellent video again again mate very helpful just one question, when you did the continuity of CPC and phase conductor with the link would that also be the r1+r2 assuming this is a radial circuit or am I getting ahead of my self 🤯 keep the videos coming all very helpful and thank you
Absolutely right Mark. I'm being picky now, but we should call it R1+R2 if we are going to put it on a certificate. But having said that, little r1+r2 is actually the same as big R1+R2 for radial circuits but not for Ring circuits so we try to distinguish between them. Next weeks video will include the differences between them and also cable length calculations from R1+R2 for ring and radial.
Excellent video Dave. Hopefully in the future videos you will explain heow to perform these tests on lighting circuits with loads connected as in real life scenario, loads brings false readings and there are situations when its not possible to disconnect loads.
Absolutely we will be doing videos on that. The concept for the channel is one topic, one video. So start with the first fix tests and then a video on testing with attached loads. That way the new starters can learn and keep up with you quick boys. Thanks for the positive encouragement, it is truly appreciated. Dave.
@@learnelectrics4402 Sir I am from India. My English is not good but i saw your all videos I can understand easy. You are my electric teacher( guru) I learn 85% from your video. Love you sir 🙏🌞
Thank you for the great comments Akash. Your English is better than my Indian even though I worked in India for some time in Hyderabad. Lots more videos to come, keep learning and please do tell your friends about the LearnElectrics channel. Dave.
Hi I have a question about insulation resistance test on ring cirvuits When carrying out the insulation resistance test on a ring circuut, shall one test on only one end of the L and N cables? Or can one link the LL and NN and test across them? Thanks again
you do not need to link LL, you have already (or should have) proved the conductor is continuous from one end to the other. Have another look at the video, it is explained.
@@learnelectrics4402 thanks for your reply. So one end will be kept loose in s terminal block/connector whilst the other end is tested. Or can it be left in the mcb?
Hi sir...can we do a phase & neutral to earth insulation test on a lighting circuit which has a dimmer switch...considering that it is in series with the line conductor..
Yes, that will be coming up in a video very soon, testing cables at second fix and with appliances attached. You can just take the dimmer switch off and replace it with an ordinary switch for the tests as that is easy to do.
I use a Unitest and a Megger, but I prefer the Unitest for Multi Function tester. The Kwetechs are damn good meters and reasonably priced. I also have a couple of Fluke Multi-meters, but those are for when I work on instrumentation panels. You can always tell a good meter, they will come with a good set of leads. Hope this helps, Dave.
sir, one of my hot cable is drawing 1A of current when i first switch on the circuit breaker with nothing connected to the cable from the other end. After a while the current will settle at around 0.3A and the wall at the kitchen feel warm to the touch. This circuit was isolated by me, so i can still switch it on and use the kicthen sockets as normal. But when i connect this hot cable with the rest of the hot cables the RCCB will trip. So i had to isolate it from the RCCB and only control it with a circuit breaker. What should i do now?
You will need to trace the cables. Draw out the circuit, where they go, what is attached etc. and then work through the possible problems. have you tried disconnecting everything from the circuit first and then reconnecting the cables and see if the RCD trips with an empty circuit, then add appliances back onto the circuit one at a time to see if something makes it trip. These problems can take a while to sort, take your time and keep notes of what you have tested. Good luck.
That's why you turn off the mains switch (between your metre and consumer unit) before carrying out these tests. In my country, neutral and earth terminals inside the meter are connected by design, you can use continuity test to confirm that the two terminals are linked.
Find a pair of wires that are continuous when joined together, then you know that both are ok. Mow you can use either as your wander lead. Also, check your wander lead from end to end on its own. If its low ohms, the wander lead is ok.
@@learnelectrics4402 What i mean is say you're testing twin and earth. None of the combinations have continuity. How do you know whether one of them is actually intact or not?
Have a look at this video on the differences between the two tests, it will help with your question. Thanks for watching, Dave. ruclips.net/video/Ax4-bZ7WDwg/видео.html
Ok here ( Canada) we don't check any installations unless there is a problem after energization. I have done an insulation tests on 600 volt industrial motor starter units that tripped the breaker to find copper traces that shorted out the breaker. ( 600 amp ) Used the 1000 volt settings on our meter. Yes I have found screws or nails in wiring after energization with a tripped breaker. I don't know why we don't take a lesson from our UK brothers. Thanks for an eye opening video.
Excellent comments Lyle, real eye openers. I know of several UK sparkies that must have gone to the same Canadian college as you. Turn it on first, look for smoke, fix the problem. Thanks for your great contributions, keep them coming. Dave.
During the Insulation Resistance test,I thought you leave all the switches connected one end,whilst removing any components that could be damaged at such a voltage, and then doing the test at the dB end,taking the line out of the mcb,and neutral,and cpc out of there own bars ??
John. at the beginning of the video we say that this is testing cables at first fix, before any components are attached and that we are making another video for testing second fix circuits, lighting, power etc.. Hope this helps. Dave.
@@learnelectrics4402 no problem Dave your videos are great, I have done my level 3, which scheme would you recommend to join? Would appreciate your feedback, regards Lee
Lee, we have a policy of not recommending scheme providers, meter suppliers etc. They are all pretty much the same price, all ask the same questions and have the same standards to work to laid down by the government. Personal choice.
Lee, check what your package includes. they should all be about the same price between 400 and 500 pounds including first assessment fee. you can do staged payments. If you are domestic only you will only need A1.1 and if industrial A1.2 as well. Check you are not paying for add-ons like gas and plumbing etc.
That's why you turn off the mains switch (between your metre and consumer unit) before carrying out these tests. In my country, neutral and earth terminals inside the meter are connected by design, you can use continuity test to confirm that the two terminals are linked.
Try to explain how your megohmmeter works when you tested Hot to Neutral and there was damage to only (1) conductor. Explain HOW the meter can detect the return current if only one conductor is damaged and you are connecting between the two insulated conductors. Go ahead, I'll wait.
Hello, many thanks for the great videos you have, i wish you will do videos while performing these tests, I'm ready to subscribe and pay for these videos in-order to learn better,, if you have such videos please let me know how i can buy,, many thanks I'm following you from the Middle East,, Jordan
Lots of videos on testing. Go to LearnElectrics.com and put the testing you want to know about into the search box. You will get a list of direct links to the relevant videos. Without an earth in the buildings you are going to be restricted on what testing you can do. Dave.
Nobody ever shows you why you do these test in such easy to follow diagrams. They tell you electrics isn't wizardry yet they expect you to just understand what they talk about without kniwing the full picture
Thank you for the request. We don't teach from a training centre anymore. Mr Covid put paid to that. But everything we taught in class will appear on video. Watch out for our series on 18th Edition Wiring Regs and the exam, starting this week. The videos will show you how we taught it and we had a very high pass rate. Thanks for watching. Dave.
The integrity of the insulation. The ability of the insulation to resist the urge to allow current to flow through it to another conductor. z and s etc. We need to go back to the grandfathers of electrics and ask them, perhaps I should do a video on the derivation of all these symbols. Dave.
@@learnelectrics4402 Hello again. Quick question please: 6:52 you say that a voltage of about 4 V is passed down the conductors. - This gives/shows a resistance 0.72 Ohms? - Would the current (if measured) be 5 Amps? and am I correct in thinking 100mA and over is dangerous for humans? 14:20 you mention that the test current is very small (as above - what size would it be?). Would it be in the range of micro or nano Ohms? And finally, why do you say "phase" for the "Line" - is there a reason for this? Again I thank you for the videos - they are bring my theory and practical work together really well!
That's a lot of questions. Have a look at page 109 in Guidance Note 3. Test voltage should be between 4 and 24 volts but most meters only have 9 volts battery. Test current is very low from a multimeter or MFT because of the battery internal resistance, in the order of mA. Don't worry too much about how the meter works. 50mA and above at low voltage is potentially fatal. But the test meter is operating at extra low voltage. Years ago we called the brown wire (red in those days) the LIVE Then the boffins decided that we should call neutral LIVE too as it carried the return current back to the transformer. Then we called the brown wire phase, but in a 3 phase system we call the three phases Line 1, Line 2, Line 3. And ... why does certain equipment, plugs etc. still refer to the LIVE when they mean phase. It's a confusing mess but we just learn to live with it. Don't even start on why we call the earth a cpc. If we were wiring a lighting circuit together and you said the live wire, I would know you meant the phase. If you said connect the earth, I would know you meant the cpc. We just do it automatically. Its a whole secret language. Good luck, keep learning, keep asking, spread the word about the channel, that helps. Dave.
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.
ruclips.net/channel/UCYaJQnpO4XAp0yCgqzMkmfA
Do you work in Shropshire often ?
How do I test individual conductors if both end of the cable in very far away locations far greater than any multimeter probes would reach?
This was the most clear & easy to follow video on this subject I have come across. Most channels only show how to test but don't explain clearly or give examples of why we're conducting the test in the first place. As a visual learner I really appreciate the pictures as well. Looking forward to more videos please keep them coming. Thank you.
Well thankyou Riaz, great feedback. So glad we have got something right. Our intention is one topic, one video and properly explained. Really appreciate your comments. Keep watching, lots more to come. Dave.
Simply the best video tutorials. better than any class room!
Thanks a bunch!
Those are truly nice comments and very much appreciated.
Thank you so much, it makes the effort worthwhile.
Dave.
Agreed.
Great video guys and a must to do just after the plastering. I recently checked a ring final circuit and found the continuity was fine but the Insulation resistance failed. Eventually narrowed it down to a plastered board screw through a cable in a stud wall. Other trades can be your worst enemy, so always check and where possible protect the cabling from potential damage. Test, test, test...
Thanks Andy, spot on comments.
Excellent instructional video - one the best I have ever seen, and I've watched 100's, many even 1000's.
What can I say. That is fantastic feedback, it really makes the effort worthwhile.
Thank you so much, truly appreciated. Dave.
One of the best and clearest explanations of these tests, definately subbed. 👍
Thanks Zed Zed, fantastic feedback. Really appreciated. Dave.
This was the most clear & easy to follow video on this subject I have come across,good job, thx a lot
Thank you Koen, much appreciated and thanks for watching. Dave.
Mr. Dave, you make learning about electricity easy.
Well done.
I hope to watch and hear more from you.
❤
Thank you for the great support, much appreciated. Lots more to come and thanks for watching. Dave.
I would like to thank you for the helpful videos that you are making them. Watching them , really helped me to understand more then College. Once again thanks
Thank you Abdul, glad you find the channel helpful. Spread the word, the more that watch, the more videos we can make. lots of good topics on the way. Cheers. Dave.
Your teaching is the best, I have learnt a lot form your videos. Many thanks.
Super feedback, thank you so much. Dave
Hi Dave, can you make a video on how to read electrical installation drawings on building site preferably UK standard. I want to know how to read the measurements on drawings, symbols and how to apply it on site. Thanks
On the list, great suggestion.
I found this video very helpful from learn electrics.
I am now more confident as Dave is great teacher.
Glad to help, appreciated.
Dave I happily jump on the bandwagon and give you a big THANK YOU.Very clear and Thorough.God Bless.
Thank you Vachik, appreciated. And thanks for watching.
Well I have watched it recently and I am very impressed by the quality and deeply explanation on continuity and IR Testing . Fabulous 🎉video
Thanks for watching. Lots more to come. Dave.
Thank you for your clarity and understatement. I wish to learn, not to be entertained. What a breath of, as you say, fresh air.
Great feedback Don. Thanks for watching and lots more to come. Dave.
Thank you. Very grateful to you for your excellent explanation. I started the job in corrosion control equipment, and some electrical operations were hard for me. But now I get the point.
Excellent, if it helped, great. Lots more to come. Dave.
@learnelectrics4402 appreciate it. Thanks. I hope to see some subjects about cathodic protection 🙏
Another great video from this fantastic channel, invaluable for people trying to retain knowledge and for young people in the industry starting out
Much appreciated, thank you. Dave.
The best video of IRT...God bles master...thankz...
So nice of you to say that, really appreciated. Dave.
Crystal clear and concise, many thanks Christopher...
Glad you found it useful. Great feedback and thanks for watching. Dave.
I am very exciting of best video presentation . I clear about all testing that you displaying in video presentation . Thanks for sharing your knowledge .
So nice of you to say so. Really appreciated. Thank you. Dave.
A precise and on point video. Simple to understand and complete
Thank you so much, appreciated comments. Thanks for watching. Dave.
Hallo Sir.Thanks for your video.I would like to ask you if there are measuring devices on the market so can someone identify where exactly on the cable a damaged insulation lies.Thanks a lot and a Happy New Year!
Another top notch explanation Dave. You're nailing it mate, pardon the pun.👍😅
Nailing it, love it. Good old Walsall humour.
Hope you are keeping well.
Once again no one explains things better. Thank you! Very easy to follow and retain the knowledge at the end.
I recently tested an installation after changing some face plates and light fittings as well as extending some sockets outlets. One of circuits passed the continuity test but failed the insulation resistance test however the RCD has was not tripping although it is mechanically sound. It doesn’t make sense so I am going back to re-test the circuit as I think I must have made a mistake like leaving something plugged in or a bulb or maybe some other mistake I made as I was tired. It would be great if you can do a video on insulation resistance testing at DB, single circuit and whole installation.
Yes, if the IR test fails, always check for things left in circuit. Usually Le and NE pass but LN fail. If its lighting remember to flick a switch and test again. Dave.
Bardzo dobrze pokazane,wytłumaczone,dziękuję ,pozdrawiam
Thank you for watching, brilliant.
Hello, many thanks for your great videos,, in my country most of the old buildings which are more than 10 years old don't have Earth ,, so what is the best way to perform the test while there is no earth conductor in the building?
You can test continuity between the line and neutral conductors and insulation resistance will only be the same, between line and neutral. Thanks for the information, good to know what happens in other countries. Thanks for watching. Dave.
@learnelectrics4402 thank you very much 🙏🙏🙏🙏
Excellent explanation Dave brilliant video
Thanks Tony, you're very welcome. I've also got 18th Edition videos on Thursdays each week. Next weeks is about Zs tables. Spread the word mate. Hope you are well. Dave.
Best video on RUclips thank you
Glad you think so, thanks for watching and spread the word. Dave.
I did an extensive insulation test between a wire and the ground, actually the wall. So I watered the whole wall with water, also above the cables. In case of damage in the wire insulation, there will small cracking sounds coming from the wall, and the resistance will be low. I put water also to easy the conductivity and find possible deffect. Also, I am testing with 1000 volts.
Thanks for the input, appreciated.
Wow you are wonderful in teaching simply.
Thank you, appreciated. Dave.
In a CNE system: ? Before insulation testing between neutral and earth of multiple circuits, is it necessary to remove the main incoming earthing cable from the earth bar in the consumer unit ?
Not the main earth, no. Leave that where it is.
Great great great effort dave.. Keep it up mate.. Thanks again
Thanks, we really are keeping it up, lots more videos to follow.
Excellent video clear to follow and is very understanding few more actual testing with my meter should help.
Thanks Tee. Really glad that you find the videos useful. Great feedback, appreciated. Dave.
This just help me clarify a fault I have in the kitchen. ❤
Perfect! The video has done its job. keep watching, lots more to come.
Great video! Keep making videos like this focusing on basics please! Subscribed
Absolutely will. Thanks for watching and spread the word. Dave.
Excellent very well explained video in a way that people can understand instead of blinding people by science like some books do also top quality diagrams
That's really nice feedback. Thank you very much Andrew and I'm really happy that you find the style of the videos helpful. Dave.
Smashing video ! just in time for my level 3 test and inspection practical test tomorrow..
Perfect, let's hope all goes well for you. As an assessor, the really important thing with practical assessments is that I want to see you set your meter up correctly before you start testing, otherwise how do you know what is a good reading and what is a bad one. Good luck. Dave.
Nice one Dave..really do appreciate the content mate
Thank you Dan and we do appreciate the feedback. Dave.
Another great video. I always look forward to your videos. Thank you.
Great feedback, thank you so much. Lots more to come. Dave.
Thanks a lot you have a very simplified but effective way to teaching 👍 😀
Thanks Luca, appreciated. Dave.
Your videos are really helping me to understand electricity. Can you please make a video on HOW TO READ ELECTRICAL INSTALLATION DRAWINGS, eg on Building site. Many thanks.
Good idea, it's on the list now. Thanks for watching.
Some of the stages of the PAT inspection’s I used to perform were also similar to this,
If someone or Spark rewired their radio/microwave and all was well i.e. correct fuse, polarity and earth pass, visually OK and correct size wire etc it would get a pass.
However this seems not to be the case for electricians in domestic installation situations.
They don’t seem to happy signing off someone else's work, I would like to ask the reason why?
Is this because the test instruments of today are not adequate enough to prove the wiring
And therefore do not give them the confidence?
Great channel by the way, one of the best out there in my opinion.
We sign for the work that we have done when wiring installations. Hope this helps. Dave.
Excellent as always, thank you
Thanks, really appreciated. Dave.
Great video. How do when know what continuity readings to expect if most of the time we don’t no the length of existing cables installed?
Thanks Paul. The point I was making was that if the cooker is only 3 metres from the CU then expect a very low reading - maybe 0.03 ohms - big csa and short run. But if it is a lighting point at the far side of a large house expect a higher reading, maybe 3 or 4 ohms - thin cable long run. It only comes with doing the testing many times. Example, when you get to know your car you can look at the petrol gauge and just know if you have enough petrol to get to work and back or whether to fill up on the way. Hope this helps. Dave.
Take a look at our video - Cable length calculations and R1+R2 on this link
ruclips.net/video/Qq_9MNH8XxU/видео.html
So good thxu easy to understand I do appreciate your videos
You are very welcome Bisoborwa, lots more to come.
Great video again thanks very clear. I was wondering if you have any advice on changing career to becoming an electrician? I am currently 45 and was considering doing a course at trade skills 4 you. I realise that the key to making it work is getting some work experience so I am currently trying to find some work experience to go along with the course as I believe this would be vital. I am a musician and have build things like guitar effects and a valve hifi amp and I enjoy learning this stuff. Do you think it can work as I don’t want to waste my money and time ? Thanks Glenn
Chris. Shop very carefully for the right training centre to attend. I always advise people to actually visit at least three centres and have a good look around, look what training material they will use to teach you, the training boards, their facilities and what books and training notes do they supply. For you, you will need a training course with a good mix of practical and theory. Please, check the different centres before parting with what will be thousands of pounds in the long run. You need to be at a centre where you feel comfortable. We don't do classroom teaching any more and we have a policy of not recommending anybody but you would be as well to check out the training from the Part P scheme providers even if it is extra travelling, you will see their logos on most electricians vans. It might cost a little more but going through a scheme provider they will guide you towards registration and they have the highest standards to maintain.
Good luck. It is a good trade and 45 is still a baby. Dave.
17:18 continuity test can also detect this fault if the other end of the conductors are open. If there is continuity then the conductors are shorting somewhere behind the wall.
Excellent extra info, thanks for the input. Appreciated.
@@learnelectrics4402 Welcome. One of my favourite channels.
I understand the tests now.Thank you.
Thank you Tracey. Lots more on testing soon. Thanks for watching. Dave.
Can I ask a question please. When testing a ring main and they have used the trunking as cpc what do you do for your R1 value and also what do you do for r1+r2 and you can't cross connect? Thank you
Good question Alan.
Using the blue 18th Edition Regs book.
Regulations 543.2.2 and 543.2.5 apply.
Conduit/trunking can be used as a cpc if continuity can be guaranteed.
R1 is the Line conductor and R2 will be the trunking.
You cannot do a crossover test as such, just connect one end of the trunking to one line and the other end to the other line.
Steel is about 12% as conductive as copper but I would imagine your trunking has a csa of much more than 8 times the copper cpc that would normally be used.
Excellent as always, loved the bit about touching the crocodile clips on IR test and you will get tested as well lol
Believe me Jimmy, it's true. Many a sparky has wet his pants doing this. Lots more down to earth videos to come. Dave.
@@learnelectrics4402 I never ever thought to do those 2 tests together, I always did one or the other. I was never shown or heard that before, and it makes absolute common sense. I have been baffled sometimes why I couldn't find a fault on an IR test yet the rcd wouldn't turn on. I am truly a lot wiser after watching this video. Great stuff
I have a meter reader don't have the test button what do you recommend for starter? thanks
Some meters are auto starting when they find a connection. Turn it on and put the probes together and see if it responds. Meggers do this amongst others.
Every manufacturer does something different. Thanks for watching. Dave.
I am new but eventually want to get into EV installing I was looking to invest in the KEWTECK 66dl bit pricey is it a good brand?
Another very good lecture Dave. By the way, I like the way you test continuity and I can wait to see the fault finding but it seems like you are doing R1 + R2 and R2 + Rn, if not I can start by doing that. Thank you once more for the well and rich lecture.
Absolutely right Omar. It says at the start of the video that we are treating this as first fix, in other words we have just installed the cables and not yet attached any accessories etc.
When the cable is newly installed we should test to confirm that all three cables are good L + N + E. It is no good waiting until all the walls are plastered and the sockets fitted to find that the neutral has a break in it. We are doing another video on testing with accessories installed. Good question and thanks for watching. Dave.
@@learnelectrics4402 I have seen electrician checking their cable before all the boarding is done but still a screw goes in the cable after the plasterboard. So, to be on the safer side, what you meant is , you check before the plaster and after.
Correct Omar. Check at first fix and if all is ok any damage that you find on second fix checks might be caused by the plasterer or carpenter. Who is going to pay for these repairs, the new cable, re-plastering the wall etc. If you don't check all your cables at first fix, how can you prove it is not you fault. For the time it takes to check at each stage it is worth it. Good luck. Dave.
Excellent video again again mate very helpful just one question, when you did the continuity of CPC and phase conductor with the link would that also be the r1+r2 assuming this is a radial circuit or am I getting ahead of my self 🤯 keep the videos coming all very helpful and thank you
Absolutely right Mark. I'm being picky now, but we should call it R1+R2 if we are going to put it on a certificate. But having said that, little r1+r2 is actually the same as big R1+R2 for radial circuits but not for Ring circuits so we try to distinguish between them.
Next weeks video will include the differences between them and also cable length calculations from R1+R2 for ring and radial.
Great Content guys, keep up the great work
Thank you, will do. Thanks for watching. Dave.
Excellent video
Thank you very much, appreciated.
Excellent video Dave. Hopefully in the future videos you will explain heow to perform these tests on lighting circuits with loads connected as in real life scenario, loads brings false readings and there are situations when its not possible to disconnect loads.
Absolutely we will be doing videos on that. The concept for the channel is one topic, one video. So start with the first fix tests and then a video on testing with attached loads. That way the new starters can learn and keep up with you quick boys.
Thanks for the positive encouragement, it is truly appreciated. Dave.
Sir excellent 🙏🙏🙏
Explanation 👍👍👍
Thank you Akash, nice comments.
@@learnelectrics4402
Sir I am from India. My English is not good but i saw your all videos I can understand easy. You are my electric teacher( guru) I learn 85% from your video. Love you sir 🙏🌞
Thank you for the great comments Akash. Your English is better than my Indian even though I worked in India for some time in Hyderabad. Lots more videos to come, keep learning and please do tell your friends about the LearnElectrics channel. Dave.
Thanks, really good video😊
Great feedback, thank you.
There videos are brilliant thank you soo much 😁👍🏽
Glad you like them, your comments are appreciated. Dave.
Excellent again!!
Rgds 👍
Thank you very much. Great feedback and always very welcome. Dave.
great video, thank you so much
Thanks for watching. Appreciated. Dave.
Hi I have a question about insulation resistance test on ring cirvuits
When carrying out the insulation resistance test on a ring circuut, shall one test on only one end of the L and N cables? Or can one link the LL and NN and test across them? Thanks again
you do not need to link LL, you have already (or should have) proved the conductor is continuous from one end to the other. Have another look at the video, it is explained.
@@learnelectrics4402 thanks for your reply. So one end will be kept loose in s terminal block/connector whilst the other end is tested. Or can it be left in the mcb?
It should already be out of the MCB from when you did the continuity test so just leave it out. Happy testing. Dave.
@@learnelectrics4402 thanks a lot Dave
Can we do insulation resistance test on bare busbars?
If you know they are disconnected from everything and are dead, yes you can, especially if you think there is a problem.
Hi sir...can we do a phase & neutral to earth insulation test on a lighting circuit which has a dimmer switch...considering that it is in series with the line conductor..
Yes, that will be coming up in a video very soon, testing cables at second fix and with appliances attached. You can just take the dimmer switch off and replace it with an ordinary switch for the tests as that is easy to do.
Well explained, thanks a lot.
Thank you Farshad, thanks for watching.
Brilliant 👏
Thanks for the feedback, appreciated,
Can we run insulation test to photovoltaic module ?
If it was me, I would disconnect the cables at both ends before IR testing. 500v on a PV module not a good idea.
@@learnelectrics4402 i plan to do the test in the evening, what do you think??
good video, well done
Thank you. Much appreciated, Dave.
what meter do you use Dave?
I use a Unitest and a Megger, but I prefer the Unitest for Multi Function tester. The Kwetechs are damn good meters and reasonably priced.
I also have a couple of Fluke Multi-meters, but those are for when I work on instrumentation panels.
You can always tell a good meter, they will come with a good set of leads.
Hope this helps, Dave.
@@learnelectrics4402 Hi Dave, the Kwetechs are a solid piece. Appreciate your prompt reply, was extremely helpful
sir, one of my hot cable is drawing 1A of current when i first switch on the circuit breaker with nothing connected to the cable from the other end. After a while the current will settle at around 0.3A and the wall at the kitchen feel warm to the touch. This circuit was isolated by me, so i can still switch it on and use the kicthen sockets as normal. But when i connect this hot cable with the rest of the hot cables the RCCB will trip. So i had to isolate it from the RCCB and only control it with a circuit breaker. What should i do now?
You will need to trace the cables. Draw out the circuit, where they go, what is attached etc. and then work through the possible problems. have you tried disconnecting everything from the circuit first and then reconnecting the cables and see if the RCD trips with an empty circuit, then add appliances back onto the circuit one at a time to see if something makes it trip. These problems can take a while to sort, take your time and keep notes of what you have tested.
Good luck.
That's why you turn off the mains switch (between your metre and consumer unit) before carrying out these tests. In my country, neutral and earth terminals inside the meter are connected by design, you can use continuity test to confirm that the two terminals are linked.
What happens if we fail a continuity test using the line as the wander lead - how do we know which wire is broken? Or if it's both?
Find a pair of wires that are continuous when joined together, then you know that both are ok. Mow you can use either as your wander lead. Also, check your wander lead from end to end on its own. If its low ohms, the wander lead is ok.
@@learnelectrics4402 What i mean is say you're testing twin and earth. None of the combinations have continuity. How do you know whether one of them is actually intact or not?
Can i use fluke 1587 for testing?
You can use it for Ins Res and continuity but it won't test RCDs, Loop etc.
@@learnelectrics4402 ty for the information..please send me diagram for insulation resistance test for 2 core and cpc pvc flat wire
Great video,keep it up!⬜🔻🔺️🔺️
Thanks Christina. That's the plan, lots more videos planned. Dave.
Kindly post vdo on insulation resistance test for wall and floor
I can put that on the list. Thanks for watching. Dave.
can you please name the 2 testes in continuity test and 3 tests and insulation resistance test?
Have a look at this video on the differences between the two tests, it will help with your question. Thanks for watching, Dave.
ruclips.net/video/Ax4-bZ7WDwg/видео.html
Ok here ( Canada) we don't check any installations unless there is a problem after energization. I have done an insulation tests on 600 volt industrial motor starter units that tripped the breaker to find copper traces that shorted out the breaker. ( 600 amp ) Used the 1000 volt settings on our meter. Yes I have found screws or nails in wiring after energization with a tripped breaker. I don't know why we don't take a lesson from our UK brothers. Thanks for an eye opening video.
Excellent comments Lyle, real eye openers. I know of several UK sparkies that must have gone to the same Canadian college as you. Turn it on first, look for smoke, fix the problem. Thanks for your great contributions, keep them coming. Dave.
Great Video!!
Thank you, great feedback. Dave.
Thank so much!
You're welcome and thanks for the support.
During the Insulation Resistance test,I thought you leave all the switches connected one end,whilst removing any components that could be damaged at such a voltage, and then doing the test at the dB end,taking the line out of the mcb,and neutral,and cpc out of there own bars ??
John. at the beginning of the video we say that this is testing cables at first fix, before any components are attached and that we are making another video for testing second fix circuits, lighting, power etc.. Hope this helps. Dave.
Another great video, great work thanks, keep them coming👍
Thank you Lee, appreciate your comments. Dave.
@@learnelectrics4402 no problem Dave your videos are great, I have done my level 3, which scheme would you recommend to join? Would appreciate your feedback, regards Lee
Lee, we have a policy of not recommending scheme providers, meter suppliers etc. They are all pretty much the same price, all ask the same questions and have the same standards to work to laid down by the government. Personal choice.
@@learnelectrics4402 ok many thanks, just quite a difference in pricing that’s all it seems to be for the same thing.👍
Lee, check what your package includes. they should all be about the same price between 400 and 500 pounds including first assessment fee. you can do staged payments.
If you are domestic only you will only need A1.1 and if industrial A1.2 as well.
Check you are not paying for add-ons like gas and plumbing etc.
Thanks a lot
Thank you Sam, thanks for watching.
Brilliant thanks
Thanks for the positive feedback. Great. Dave.
Thank you
You're welcome Jimmy, thanks for watching. Dave.
Hello.
Thank you for your very interesting videos.
can I have a written text of your lyrics and comments?
thank you
Thanks for watching, much appreciated. The only words available are in the video. Dave.
Sir kindly provide test for Insulation for
Will do.
Thanks✌🏼
My pleasure Arjun. Thanks for watching.
Y getting continuity between neutral and earth .
Don't forget that N and E are connected at some point in the system. If you,ve not disconnected at the consumer unit end you will pick up a reading.
That's why you turn off the mains switch (between your metre and consumer unit) before carrying out these tests. In my country, neutral and earth terminals inside the meter are connected by design, you can use continuity test to confirm that the two terminals are linked.
Try to explain how your megohmmeter works when you tested Hot to Neutral and there was damage to only (1) conductor. Explain HOW the meter can detect the return current if only one conductor is damaged and you are connecting between the two insulated conductors. Go ahead, I'll wait.
If the insulation for the good conductor is of the correct spec, then the test will pass. The test voltage will not penetrate the good insulation.
This explanation applies to the three-phase
Thanks for watching. Dave.
Why do you get low IR when appliances connected on the circuit , even when you do LN to E and you know nothing wrong with appliances ? 🧐
All appliances will affect the IR. Have a look at these two videos.
ruclips.net/video/tT3eGK1b0Yk/видео.html
ruclips.net/video/g901A_PSXTY/видео.html
Hello, many thanks for the great videos you have, i wish you will do videos while performing these tests, I'm ready to subscribe and pay for these videos in-order to learn better,, if you have such videos please let me know how i can buy,, many thanks I'm following you from the Middle East,, Jordan
Lots of videos on testing. Go to LearnElectrics.com and put the testing you want to know about into the search box. You will get a list of direct links to the relevant videos. Without an earth in the buildings you are going to be restricted on what testing you can do. Dave.
@@learnelectrics4402 many thanks for your reply 🙏 highly appreciated
👍👍
Thanks Mike.
Nobody ever shows you why you do these test in such easy to follow diagrams. They tell you electrics isn't wizardry yet they expect you to just understand what they talk about without kniwing the full picture
Thanks Richard, great feedback and thank you for watching.
🎉🎉🎉🎉🎉🎉🎉
Thanks for watching.
I'm here again
Its good to see you back again.
Si I request you please send your academic learning training address please
I would like to join your training center please
Thank you for the request. We don't teach from a training centre anymore. Mr Covid put paid to that. But everything we taught in class will appear on video. Watch out for our series on 18th Edition Wiring Regs and the exam, starting this week. The videos will show you how we taught it and we had a very high pass rate. Thanks for watching. Dave.
@@learnelectrics4402 thank you
🙏🙏🙏
Very welcome Akash
👌👌 🇧🇩
Thanks for watching.
Making breakfast enjoyable..
Glad we can start your day right for you. Thanks Dennis.
Dave.
What does insulation resistance mean and why are letter like z and s and e used why do they make things complicated grrrr
The integrity of the insulation. The ability of the insulation to resist the urge to allow current to flow through it to another conductor. z and s etc. We need to go back to the grandfathers of electrics and ask them, perhaps I should do a video on the derivation of all these symbols. Dave.
Thank you for the excellent video:
Great feedback. Thank you so much. Dave.
@@learnelectrics4402 Hello again. Quick question please:
6:52 you say that a voltage of about 4 V is passed down the conductors.
- This gives/shows a resistance 0.72 Ohms?
- Would the current (if measured) be 5 Amps? and am I correct in thinking 100mA and over is dangerous for humans?
14:20 you mention that the test current is very small (as above - what size would it be?). Would it be in the range of micro or nano Ohms?
And finally, why do you say "phase" for the "Line" - is there a reason for this?
Again I thank you for the videos - they are bring my theory and practical work together really well!
That's a lot of questions.
Have a look at page 109 in Guidance Note 3.
Test voltage should be between 4 and 24 volts but most meters only have 9 volts battery. Test current is very low from a multimeter or MFT because of the battery internal resistance, in the order of mA. Don't worry too much about how the meter works.
50mA and above at low voltage is potentially fatal.
But the test meter is operating at extra low voltage.
Years ago we called the brown wire (red in those days) the LIVE
Then the boffins decided that we should call neutral LIVE too as it carried the return current back to the transformer.
Then we called the brown wire phase, but in a 3 phase system we call the three phases Line 1, Line 2, Line 3.
And ... why does certain equipment, plugs etc. still refer to the LIVE when they mean phase.
It's a confusing mess but we just learn to live with it. Don't even start on why we call the earth a cpc.
If we were wiring a lighting circuit together and you said the live wire, I would know you meant the phase. If you said connect the earth, I would know you meant the cpc. We just do it automatically. Its a whole secret language.
Good luck, keep learning, keep asking, spread the word about the channel, that helps. Dave.
@@learnelectrics4402 thank you for your knowledge transfer. Its making sense now. Kindest regards.
Great. All learning begins with a question. Dave.
Thanks a lot
Happy to help and thank you for watching. Dave.