SAFE ISOLATION PROCEDURE for Electrical Circuits. Why we do it, how we do it.
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- เผยแพร่เมื่อ 3 ก.ค. 2021
- This video looks at why we carry out safe isolation procedures before working on electrical circuits and installations.
So very often people will simply just turn off at the wall or consumer unit and assume, hopefully, that the circuit is now safe.
Unfortunately this is not so. Several people each year are injured when they take hold of an electrical conductor that is live when they expected it to be dead.
Safe isolation involves a very short sequence of tests that can give you confidence and certainty that all parts of the isolated circuit are dead.
Explained in clear and easy to understand terms this video helps to put the sequence of tests into their proper context.
Why do we do the tests, how do we do the tests. We answer these questions.
This video is No.75 on our TH-cam channel where we have videos on a wide range of electrical topics.
To see a full list of all our LearnElectrics videos, click on the link below.
/ @learnelectrics4402
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Always work safely, electricity can be dangerous. If you are unsure, stop and seek advice.
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There are many videos on many electrical topics including Installation, Part P, 18th Edition, Testing, Certification, Lighting, Sockets, Ring Circuits and much more.
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Can you do a video on how to do install a socket outside may be in garden or just outside at the front door etc.
A basic subject that is often taught just as a procedure or drill without the student really understanding the reasoning behind the procedures. This explains all and better just with diagrams ! 👏
Thanks for the excellent feedback. That is exactly our method. Show you what you need to understand rather than just tell you the minimum. Thanks again. Dave
Wow! This is video very informative and the best tutorial on the topic for me so far. I really appreciate it. Thanks for sharing it with us.
My pleasure Daniel.
Thank you Dave. Appreciate the quality and content of the video.
Thanks for watching. Appreciated comments. Dave
Thank you Dear for all this help.
You're most welcome, thanks for watching.
Another excellent video Dave. Thank you again for the clear explanation.👌 I am now well and truly hooked on your channel.👍
That's what we like to hear Chris. Thanks for watching. Dave.
Thanks a lot Sir
Thank you Ramzi. Dave.
Thank you as always !
Thank you Tony. Thanks for watching. Dave.
Great video Dave, one question that has always remained a mystery, is why isn’t disconnecting live and neutral, and making the ends safe inside the consumer unit, considered an approved method of isolation? Surely a physically disconnected circuit is safer than a locked off one? 🤷♂️
You are totally right. The IET approved method though is to leave the wires in situ. Personally, I always took the phase out of the MCB and neutral out of the neutral bar. That way, whatever happened at the MCB would not affect me. Leave the earth in the earth bar for the insulation resistance tests. Good stuff. Dave.
Can you do video of safe isolation of alternate supllies eg solar, wind, battery, engine. Risk asessments and safe work method statements ?
It's now on the list to be done. Thanks.
Thanks. This could cover transfer switches automatic and manual, Main switches marking and grouping, etc etc etc
Hello Dave thanks for the video. I had a question, are there instances when we have to isolate the whole board and not just the final circuit that we are working on?
Yes of course there are. In fact I have sometimes isolated the whole board when the inside is "messy". Changing MCBs, carrying out an inspection and test on the premises. If you are happier isolating the whole board then do it, after all it's your hands that you are putting inside. The safer the better.
Thanks a lot for all your clips. Pls can you do a tut on how to select the right distribution board depending on the electrical load, overheating, etc ?
We could do Pabor, but it all comes down to you on site. How many circuits and what is the loading. Thanks for the request, appreciated. Dave.
@@learnelectrics4402 3phase main breaker(switch) 42 circuit breakers, 100amps load. What I really what to know is what really determines the panel to be used?
That's only an average of 2 amps per breaker. the panel must be able to take at least 42 breakers. Everything else can be bought to fit into it, but if the cabinet only takes 30 breakers, well, that's a problem. Consider a 48 way cabinet or split it into 2 x 100A 24 way boards.
@@learnelectrics4402 alright, thanks a lot.
Best video ever
Appreciate your comment, great. Thanks for watching. Dave.
At 4:38 you say for reverse polarity L-E is 0 volts. This should be 230 volts. I mean the load is live with neutral switch open. The load is live on each side with no current flowing ? Please confirm if what i say is correct. Thanks for excellent video discussing isolation. Especially the the safety when using double pole switch.
The video is correct. Follow the route of the electric from the supply transformer.
In your diagrams, you demonstrate the safe isolation of a single circuit by switching off the associated MCB. However, if the circuit neutral remains connected to the neutral bar and the neutral is then cut, would a neutral-earth fault then result, causing the RCD to trip?
Yes, that sometimes happens Paul. Makes me jump out f my skin. I would often remove phase and neutral when isolating, but we have to show you the way that the book shows for assessments etc. Good point and thanks for watching. Dave.
BTW, great content, even for those who've been working in the trade for a number of years
In your sequence you are not saying when you are switching off the MCBs and the main switch, you should say when that is done! Where is it? INNIT?
Thanks for watching. Dave.