RCD TYPES - AC, A, F & B - WHY ARE THEY DIFFERENT- WHAT ARE THE TESTS - PROTECTIVE DEVICES PART 4
This LearnElectrics video is part 4 of our mini-series on protective devices where we take a simplified look at the different types of RCD.
We will look at the different types of tests that we must carry out, the mandatory tests and also those tests that are optional and not a requirement of BS7671 Wiring Regulations.
The first question that always pops up is - what is an RCD? So we will take a simplified view of RCD devices, and how they work, before moving on to the different types, why we have different types and what tests must be carried out and recorded.
And the second question is often - do I need a new meter?
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I've been qualified for over 40 years now and learn something new from each of your videos. You have the ability to explain what can be complicated in a straight forwards and clear way. Keep them coming and thank you.
I certainly will Dave, glad you like them. Dave.
Simply the best! As usual - gold. Clear and easy to understand therefore remember. Thank you, please keep going.
Thanks, will do, your comments appreciated.
Wow! This is very informative, thanks for sharing it with us. It worth it
Glad it was helpful.
Nice one Dave 👍
Glad you enjoyed it Brian, thanks for watching. Dave.
Thanks for the video, very informative.
Glad you enjoyed it, thank you.
Great video once again👍🏻
Thanks for watching, appreciated, Dave.
very informative video
Thank you, appreciated.
The best lecturer on electricity. Please, can shared neutral cause RCD to trip?
Yes it can , depending on where the circuit breakers are connected to. Thanks for watching. Dave.
Dear oh dear . Sorry to correct you Dave , but on on slide you said set instrument to AC for all types being tested. Then in another slide you said order test can not carry out the test you must have a test made specifically for theses tests . wrong BS 7671 Amendment 2 no longer requires use to do the 1/2 x test or the five x test, BS7671 now only requires the 1x test and all RCDs irrespective of type must be tested with an AC current at 1x I ^n at 0d and 180d . Older testers can still be used, I use a ROBIN KTS1620 and a Kewtech KT63 , we can do the 1x test and the 1/2 x test if we choose to and we are not required to test on anything more than the AC setting . Personally my testing hasn’t changed I continue to do all tests and I treat all RCDs as AC type.
Sean, have a look in the IET Electricians guide to the Building Regulations. Page 127. Half test is mandatory. Kewtech are a good piece of kit. Yes, you will need a tester made for the job for the optional tests on Type B etc, Thanks for watching. Dave.
Hello. Very interesting information about its Regulations. I am from Argentina. In my country we must try with 1/2x, 1x, 2x and 5x. Do you think that only 1x is really enough? You know what the justification is for having made that decision. Our grandparents were wrong to ask for 1/2, 1, 2 and 5. thank you. greetings.
@@learnelectrics4402 wrong I go by BS7671 and the onsite guide and Guidance note 3 which say the 1/2 x and 5 x test are optional for fault finding purposes they are not required BC dose not over write the IET BS7671 who I have spoken to on the phone about this and yes they say we are only required to test at 1x I^n AC . But I said I still do all the tests . There no reason not to. I also told you a while ago the I the the IET dropping theses two test is madness and a step backwards. In the 30 or so years that I’ve been an electrician I have never had to deal with BC in fact I never even heard of them till a couple of years ago. All why do you think the 1/2 x and 5x have been removed from the schedule of test certificate , so there is nowhere to record the results.
I had an rcd that was protecting the whole csu. However, plugging in my tester, the rcd would not trip & the rcd test button would not trip it either. I replaced the RCD & had the same problem, i tried another RCD.... same problem!! It turned out to be a neutral to earth fault on the lighting that stopped the RCD from functioning !!! Rather odd i thought, as normally a neutral to earth fault would cause tripping !!!
Glad you found it and good info to pass on. Thanks.
Is it possible to install an AC type RCD together with a B type?
Why? Just install a B type, it does the job of an AC type as well. have another look at the video, Hope this helps, Dave.
At 2:20, it shows 30mA for TT as fault protection. Is it not 100mA?
We can use 100mA to protect the cables etc of a TT system but we still need to protect the people in the installation. Here, at the board, we are protecting people. We call it fault protection as opposed to additional protection as the mcb will not give fault protection in a TT system, only overload protection. Hope this helps. Dave.
@@learnelectrics4402 Your channel is the best! Tomorrow, I’ll finish the last 15 recent videos! It took 2 weeks to watch all of them from the first!🤓🤘🏼
Thanks for watching. keep learning, its a good trade. Dave.
RCD saves a life. (1) RCd, different types, common men or electricians may not understand which one to apply. There are many times of electronic equipment in-house. The best option, Government Regulations, manufacturers write in user manuals, and the type of RCD to use. RCD saves a life. (2) As per BS, RCD must be tested for six months. Does the consumer to open the electrical panel, and test it. They normally do not do this. If tested on full load, arc produce and contact is slowly eroded. (3) In TT installation, RCDs are used for shock and fire protection. As per BS, we must switch off the main every six months. Can we do this for complete buildings? I asked questions before but no reply.
You would need to ask with the maintenance foreman for buildings. They may not want the building turned off. Always check with the client first.
workn a simple and easy way. RCd, different types, common men or electricians may not understand which one to apply. There are many times of electronics equipment in house. Best option, Government Regulations, manufacturers write in user manuals, type of RCD to use. RCD says life. One question, RCDs to test every six months as per BS. 1, Consumers may. not be testing. Mostly No one does 2, If you test on full load, spark creates, contact of RCDs damage. 3, TT System Earthing, RCDs to test six months, even for main. You lose complete power supply. Is it suitable for high rise or Industrial plant having own transformer. Best option is TN-S system.
corrections, instead of workn, read you explain
Thanks for watching, appreciated,
Thank you, lots more to come. Dave.
Please, reply to my questions.
First!!!
Thanks for watching, appreciated, Dave.