TYPE A RCDs ❌ Why does my multi-function tester show a FAIL?
Type A RCDs are now common within electrical installation offering improved electrical protection compared to older Type AC RCDs. However, the procedures for testing are a grey area with reference to BS7671. This often leads to an apparent test failure of a device when using preprogrammed settings within multifunction testers.
In this special round table debate, Gary Hayers explores the topic with
Shahid Kahn -Technical Manager - Electrical Contractors Association (ECA)
Peter Wade - UK Sales Manager - Megger
Ian Peacock - Technical Manager - Lewden Palazzoli
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❌ This content on this channel is for electrical professionals.❌ ==================================
📹 Presented by
Gary Hayers - Editor eFIXX
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#efixx #electricians
That was really interesting. There's so much ambiguity in this industry. It shouldn't really be Efixx's responsibility to bring this sort of information to your electrician's attention. The IET, NICEIC, Napit etc really must do better in my opinion.
Completey agree. Its like we are guinea pigs figuring this stuff out for them.
Well I would bet if next week they had fluke, napit and Schneider on they would be different to the three guys here, and there lies the problem, they should all be singing from the same hymn sheet. And not leaving it up to the person installing these things to make the call, because if something were to happen it would be that poor sod carrying the can, and not the people in the video.
I totally agree efixx has educated more people in a short time than all the electrical safety organisations collectively, I’m so glad of what efixx is doing and wallet is still in my pocket, I do have to admit I have purchased a good few products on the back of your videos.
@@gavkit Efixx put out some great content mate. Always well explained and relevant to what's going on in the industry at any given time. Problem is what about those who don't follow channels like this? They clearly aren't being giving this sort of info from their approving bodies. That's why there is such inconsistency between contractors and the industry in general.
This actually came up during my NICEIC inspection this year and the inspector asked me to test AC and A, AC RCBO's passed fine, on A they fell outside the limit which he thought wasn't right but I having tested enough of them realized that it's a common occurrence for during A testing for them to "not pass". This honestly is a typical case of technology, standards and organisations not keeping up with one another.
Great discussion and once again Gary is shit hot, clarifying each point as it's covered so no one is in any doubt. Thanks very much keep the content coming, every day is a school day.
Gary is one of the best teachers / instructors I've ever seen. I'd love to be in his classes. Great discussion, everyone :-)
This is a minefield! What is the point in carrying out every test if we don't have the values to check to? The NIC EIC clearly are not aware because when we started installing type A RCD/RCBO's as standard they wanted the type A test recorded. There is only one box for this. Not even x1 & x5 as previous issues of the 17th edition type. I have had problems with Hager DP RCD type A, with tripping times in their split load boards. After sending items back and speaking to their technical because wholesalers no longer know their products. I was told that I can only test the Hager RCD under no load. So all the training and years of experience testing from the furthest point of the circuit or where the highest Zs was recorded went out the window. So they are happy just to tick a box and not have the equipment working within tolerance in real life situations. You are told that everything stops with the manufacturer's instructions/advice as it can comply, beyond BS:7671 and not necessarily be exactly inline with the regs. I now fit RCBO'S anyway which don't suffer the same problem when testing the type A RCD. Which I have now been told is not correct and unnecessary. But I don't have the information of what the results should be when testing at this setting lol. You couldn't make it up.... And they wonder why all electricians think the IET has a conspiracy just to sell more books and the NIC EIC to run more courses and make you pay for more schemes of work. I knew I should have been a plumber. They only get checked every 5 years, if that
This is proper content 👍 not paid for promotions. Just calm and mostly clear discussion.
Genuinely think efixx provide better information than NICEIC etc etc Great work efixx Team!
nice to see Ian and peter having a proper discussion about it and shahid like a true politician, do the minimum required but if you want to test further you can
👍🏻
The best bit of electrical knowledge/advice I’ve ever hear from a single source in my career. Yes please do more. This platform has brought my once a year education to an every week education, many thanks to you all guys
Great content Gaz, would love to see more of this type of content. So good to have different opinions on a subject. I mainly deal with BS7909 for temporary events and AC type RCDs are not recommended for use in temporary events due to the large number of switched mode power supplies creating DC leakage which can 'blind' an AC RCD. I like to see only A types if possible, and certainly in Europe, type ACs are now rare. I have a Megger tester, and it does make you think that the tester manufacturers who have testers which are more software based, are better placed to push an update to the tester, or even for the user to make their own set of tests, to test RCDs fully, so testing an A type as an A type, then as an AC type, the MFT that can do all this with a couple of button pushes will be more attractive than the tester than you can only turn the dial on! This needs more guidance in BS7671, and discussions like this will only help electricians understand what they're testing. We're in the youtube generation now, and so people who only wait for the next update for BS7671 will be at least a year behind current thinking. I always try to go above and beyond the regulations for testing, as the more you test, the more you find, and the better your understanding is. If you ever want to discuss BS7909 more, get in touch!
Yeah it could be a simple firmware update to many MFT's to add that functionality. Bit of a pain for those with older testers that could potentially have to update their tester if that becomes part of the new testing schedule though.
Thanks a lot for taking the time to pull that meeting together. Sounded to me that (for now) electricians just test on the AC setting. BS7671 tripping times are only geared towards AC type RCDs, so trying to measure anything else is somewhat meaningless.
So it seems, the type A RCD test is apparently pointless, as we have no reference point to compare to, also the settings on our testers are different to the values used by the manufacturer of the RCD's anyway, so what is the point of having the facility to test on the type A setting anyway. Just appears to have been a marketing scheme to sell new test equipment.
Love how nobody wants to go down the arc fault detection route. Great video fellas.
Megger chap just trying to sell more meters. You could see him getting f**ked off when the experts suggested testing on AC is all that's needed.
So the moral of this story is always set the testers to type AC no matter the actual RCD type. If that passes you are good, and no real reason to test any further. 😁👍 I notice that most sparks on YT always test only with the type that is in the CU. They really need some education on this subject as well, and by the sound it most do. When the breaker manufacture, tester manufacture and standards group can't agree it really shows how messed up this is. 🤦♂️🤷♂️ Great work Gary, keep up the good work! This sounds like a public service announcement that really needs to be published to all sparks country wide. Single page info graphic for this and put it in every panel and RCD box. As I have always said, that minimum code standards are a "D-" one step away from failing.
I admit a few times I’ve forgotten to change the type of RCD on my tester😬 And then test again with the correct AC or type A etc but I get different readings respectively. If the regs “paperwork” require an AC result why are we buying fandango mft’s that test A’s etc? Or are we gearing up for some new paperwork for the 19th edition that requires both as mentioned? How many more boxes are we going to have to fill out that the customer can’t understand? A brilliant vid guys that even you had to scratch your heads and say “hey? hang on a minute “🤔🤔 Keep em coming😊👍
Great content, thank you. I have found the recent videos very interesting, informative and enjoyable, it's great to see the more technical topics explored in depth. Sharing knowledge is key here and this channel has become a great resource for that.
Why then don’t the manufacturers test each breaker with a pass label showing all its trip times and including A type test at point of manufacturer. I have never understood why a brand new meter is taken as ready to go and calibrated but a simple RCD is a taken as a test it yourself mate . Seems very strange
Great video. Brings up several points. BS7671 has no real info on how to test a type A RCD. It should state it needs 2 tests, one for AC and the second for type A it should also state the disconnection time and currents. In fact it should list all the RCD types separately and how to test them and what to expect as result. As BS7671 is the minimum requirement. CPS's, IET and recertification bodies should contact there members and advise how to do the tests correctly which at the moment is just AC test. Clearly the industry needs this further education. Manufactures and wholesalers of type A's should add a sticker/label/ bit of paper in box to advise of how to test these units to the current standard and the extra test that can be run and state the disconnection time and currents. MFT manufacturers and calibration centers could add this as a sticker on the units. In the long run type AC RCD will become retired and type A B F S will remain. Some counrties banned type AC RCD years ago.
Great quality content and great discussion format. Seriously a level up from usual. Really good to hear points of view being bounced between the component manufacturer, the regs and the tester guys. I'm in the electrical industry overseas but I learned a thing or two and I was riveted from beginning to end.
More of this format coming soon 🙏
"How would I test a fuse?" 🤣🤣🤣 Good point!
Love to hear what Mr David Savery has to say on this 👍
Absolutely brilliant video. Thanks for the detailed info about a complex subject.
Great stuff, great info. Really highlights how how various standards from manufacturers both equipment and suppliers can overlap on each side of the fence with the poor spark and client in the middle and 7671 still putting its shoes on to join the party when everyone else is on last orders!, nice one efixx 👌
And on that bombshell...... Good discussion. I've had much the same explanation from Lewden tech support recently about RCBOs. Hopefully Amendment 2 will shed light on this and clarify evrrything (I won't hold my breath). We had a lot of discussion about this on my 2391-52 course last month too.
Great discussion and interesting points made. Possibly the manufacturers could put a note in the box to advise that if the AC trip time is in tolerance then the product is serviceable.
Gary, when you look back at the end of the year of Efixx output this one will be right up there.
Thanks to all for doing this discussion, it was very interesting. Looking forward to the future discussions alluded to.
Thanks for watching John 👍🏻
This was a great discussion. I must admit that I have just matched my tester to the RCD type and then done the test. From now on, I will be doing A & AC tests on type A RCDs.
Brilliant video efixx, very informative discussion. Thank you.
This is really informative , thank you. Does make me wonder why we all upgraded our MFT's to enable type A testing when it's not necessary 🤔
great discussion keep up the good work for me with a KT63 I only have one setting so I'm stuck but I'm sure it covers to tests that are required
Fantastic info , much appreciated EFIXX.
Thanks for commenting and watching 👍🏻
Gary, another brilliant educational video. Thank you.
Very well put together discussion I have been in a wholesalers when someone was returning all his rcbos and board for the equipment not to be passing testing After a talk with guy about AC testing only not only A testing it made sense to him. We only use lewden now as the rolls Royce of equipment and I have surgested that this info is printed on the rcbo box and also add a small chart in the sticker pack to write A testing results direct off rcbo to stick next to board so has ongoing referance Thank you to all 4 of you good discussion 👍
Lewden and ECA say test on AC. Guy from Megger says test on A and AC. My Megger 1552 only tests AC and I am not buying a new MFT just to test at type A.
I'm the same got the previous type Megger MFT 1552 NICEIC visit said to me that I needed to get a new meter and could never see why when I am testing to BS7671.
MFT without type A test, unthinkable here in Germany since type A is standard for ages. In 1983 type AC was banned for new installations with a transition period until 1984. Since then the type A are standard here. So this RCD type did not fall from the sky yesterday 😉 Never seen a type AC RCD here, not even in old installations. Either it's type A or no RCD at all.
@@Marcel_Germann that's crazy! Shows how far behind we are.
@@Daniells1982 Not on everything, some installations here are quite old. Some even have TN-C in the final circuits, that was permitted until 1973 to do so here. So instead of a separate neutral and CPC you got a PEN. But you can't force the owners to rewire this if the installation is still meeting the requirements from back then and itself isn't unsafe. And then you can't install RCD protection, because the RCDs here also isolate the neutral, or in that case the PEN which is a big no no!
The MFT1500 series can test a A type By pressing the blue button you can select “dc” on the screen and this is the setting to use We have recently posted a video showing this
Simply put the device standards SHOULD specify the trip times AND test requirements and 7671 include them as excerpts, this would remove ALL ambiguity from 7671 and put the onus on the manufacturer to meet the standard and on BSI to ensure they (trip times in the standard and testing methods) are suitable. If we're approaching it not knowing whether to test on AC A B or combinations then at the heart of it the standards have failed not only us as electricians but also device OEMs. The whole point of a standard is to ensure there is uniformity and a common approach to doing things to if we have a device OEM and a testibg equipment OEM not singing off the same sheet then something is wrong - After-all we as Electricians put our faith in OEMs that the products are suitable and perform as intended and that the testing equipment (and regime/process) is fit for purpose and meets that fundamental principle at the root of everything we do "....to ensure safety of livestock, persons and property"
Brilliant topic.. these are the useful information we need.. i would love to see more arguments/ explanations .. there are many more similar points .. Well done Gaz for organising this chat
Great video, just getting back into the industry. The different types of rcds is new to me. Have videos on the different types and seen the setting on our testers. Today was the first time. Ive heard about the testing problem. Thank you again. Once again as said i other video comments. This is one for instructors should make the. Aware of this and highlight/ amend there regs books etc. Whislt we let the IEE catch up. Thanks again.
Our niceic assessor made us aware of testing the type A rcbo on AC and type A setting using our megger so we already carry out testing for both and record the highest value. Now all we need is for megger to let the tester roll from AC to type A on auto to save us the time when testing. Thanks for the information as many would not know without this video explaining.
As usual awesome content thanks eFIXX
Really good to see this, excellent content. Interesting to note that the wording for the testing of RCDs had changed in Amendment 2 BS7671:2018+A2:2022 reg 643.7.1 and 643.8 to take into account the discussion in this video.
Brilliant civilised debate from three different perspectives all trying to understand and solve a common problem. Many loose ends still.
Very informative. Keep up the good work
Thanks for the support
Great content with opinions from three sections of the industry discussing a topic. Would love to see more on grey stuff like this
Thanks for commenting and watching - we are planning more videos like this 👍🏻
Quality video guys, very interesting. This could be the new Saturday night viewing
You know what could have topped this discussion off @eFIXX, is practically doing the tests on a real test circuit setup and seeing real results, and then discussing what happened and why.
Very good discussion thanks again Gary and co
Brilliant discussion. Very informative and I hope you’re all good friends still.
Excellent Video. I think this highlights the fact that not enough is being done by scheme providers and training bodies to ensure that sparks actually understand the products they are installing. Many believe BS7671 is the be all and end all but fail to understand that is a “minimum” standard as the guys pointed out. Personally if I’m installing an A type rcd I want to rely on my own findings and not that of a manufacturer because when something goes wrong I’m sure the first card they will pull in a court of law will be “well did you test and install it correctly?” and then start pulling all sorts of tables and documents on you. BS7671 is non statutory and I am sure they would also lean on EAW 1989 to push the responsibility back on you.
Hi Joe, thanks for your videos! Really helpful - especially the science and maths ones, which I really enjoy... What I'd like to know is this - I've got a bonding system on a motor yacht and I'd like to measure the resistance of the bonding cables because we are suffering from galvanic corrosion. I don't think I can use a multi-meter for this - do I need a multi-function tester? If so, why? Thanks!
What a winner this video is bringing us all bang up to date on the new tech
Awesome well done eFixx. Interesting I'm having an issue with RCD within EV unit, manufacture is blaming my testers. So according to the IET pull the cables out and test it at board. Really!
Added complexity now as some manufacturers only have the DC leakage bit of the RCD in the charger and rely upon a Type A upstream.
Brilliant, thank you. 😊
Great subject, tech is changing and the regulators the rule makers need to keep up with amendments.
Great discussion, learning daily
Excellent content. Good knowledgeable guests there Gaz.
How is your practice being adjusted with regard to RCD testing? I have a different view being in the states where testing is more embedded in industrial settings than residential but in my own home I am testing beyond the basic standard actually more lab science testing using scopes and very specific waveform injections to get a view of GFCI variable operation/ tolerance. Very interesting debate and really putting these gnarly issues out there. I wonder what the E5 group fellas would make of this.
Excellent content Gary. I’ve taken notes.
Interesting to hear this, however only the electrical industry could introduce a product and the main people in the loop have different opinions and just like the regs makes things as clear as mud. And they wonder why there's confusion
Great vid, am i right in thinking the minimum requirements of BS7671 is to test all RCD's on the AC setting, including type B's
very good taking points in this video well done I think you have done some video on this with the Hager A type RCBO back a while ago
Good debate, raised real issues, personally I would never use a power tool to tighten an electrical terminal, though I don't own a torque driver yet, the earth leakage clamp meter ( Megger ) , impacts helping in real Life issues that clients have with dual RCD board's, obviously rcbo's way forward here, but whats next, wave form analysis ?, of appliances!
Great discussion and very informative. Cheers Guys. Great to see the discussion and perspectives from 4 sides of the industry around a table ( that's not there as they've made seats out of them!!) Shahid still not #aboveeddie 👊😎👍
Excellent and informative conversation 👏 👌 took a few notes from it myself for research 👍 thanks to everyone involed and keep up with the 5 star content cheers Gaz!!!
and the new AMD 2 pretty much reflects whats suggested in the video.
@@efixx thanks for that also I'm in college this weekend so that will help 🙂
I deliver C&G 2382 in the college and this is something I've been hammering on about on all my courses since the 18th came out. Spotted the equal to or greater than 5x straight off the bat but hadn't seen or heard anything from any of the iet/niceic/select seminars prior to the 18th going live. Are some manufacturers not now supplying a separate label with the appropriate test current and setting with their RCDs.
Great update Graham 👍🏻
Excellent discussion guys. It’s would be useful if you could give the guests badges so we can more easily see where they are from while they are speaking.
Great stuff guys..... Fantastic video.
This is a really insightful video. Nice one guys :-)
great video , on a very interesting topic 👍
Lovely stuff, thank you.
Being an electrician is a ball ache.
Amen. Edit: But it's just 3 wires innit
Great tech informative session
Awesome video as always👌🏻
👍🏻
Even for beginners this was very educational
Excellent content and good discussion. Super interesting. Don't know why I am watching it as I have been retired 11 years !!..lol
Sounds like a balls up to me again and will be interesting on inspection day on opinions
That's putting it mildly, pushing these things like crazy, yet no one agrees how they should be tested, they will wait until a few million have been installed, then tell us how it should be done😂
Above 30 mA the human heart can go into fibulation, so the purpose of additional protection is to save human life, by limiting the current so it does not exceed 30 mA and limit the time duration to below 40 ms, which is two complete cycles. With new technology effecting the RCD's with DC feedback the manufacturer's of RCD's and the manufacturer's of test equipment need to stop all the waffle realise that equipment needs to be developed to test them correctly even under load thus proving the time duration is kept to a safe level hence saving life
Well that cleared that up!
Thanks for watching 👍🏻
How good is Ian 🙌👌 All great guys clearly but Ian was on a different level 💪
Take away: For type AC, A, F, B RCD’s, testing can be done for only for AC function (with existing instruments in the market). Please correct me if am wrong
My take from this is : Mr RCD says the A test in existing MFTs is not done to the levels an A type RCD is required to perform. Result - perfectly good product is sometimes returned as faulty… Further, only the AC test is BS7671 mandatory and any second set of MFT tests on A settings may show a (false) fail due to the above. Please let me know if I have misunderstood :) .
Gotta love these Chairs. Recycled and solid. Is there a video for these chairs 😅
Oh dear, sticking to the installation regs is hard enough for most.
This was really interesting although most of it was over my level its something I often see in the EV industry which is manufacturers understanding and doing stuff to which the regs haven't yet caught up or understood one of these was PEN fault. Charge manufacturers saw a way of getting around fitting earth rods and responded however the regs didn't recognize what they did till later and you'd have some electricians complaining what they have done doesn't compile with the regs although as we know now they do.
I've only tested the A type breaker when feeding a car charger. With everything else I do a normal rcd 1x 5x test
Great video. Never knew about allot of the info. Don’t think it can always come to the contractor ignoring documents all the time. Like the guys say niceic and napit etc should maybe be informing contractors. Also I when I did my 18th update I didn’t learn anything new. My knowledge came from places like efixx and sparkyninja. The courses do seem to just want pass marks and get people through. Education never stops
Thanks for the support and commenting. 👍🏻
Having bought an RCD this year and noted Nagy (??) finding an RCD that didn't trip but did trip via the test button - proving that test buttons are useless, where I've fitted the RCD, I've set up my own test button (29mA) to test the RCD and removed the test button fitted to the RCD !
Very useful.
So I brought a new kewtech MFT for no reason as my Robin KTS 1620 MFT is perfectly acceptable as it has a DC RCD function , witch I don’t really need as I can just test on ac only? Brilliant video very interesting , 👍👍👍👍👍👍❤️⚡️fantastic video Gaz as always
My Assumption (based on manufacturer catalogs) was: Type A is also completely Type AC, but in addition does the semi-rectified currents. Just tested all RCBOs in reach and all of them pass with almost identical values in AC and A tests (auto test) fine. But all of them are electromechanic ones. Seems to be a problem with electronic RCBOs? Not a very pleasant perspective that your safety basically depends on software nuances, since I would expect it to work with AC fault currents just fine... After all it's the "usual" fault current when people are touching broken extension corts and such. A bit lame how the Lewden guy tries to get away by tossing formalities and tabulations around...
This was interesting but have you raised the point with the IET? They are always taking feedback and with the speed we have gone through the last two editions with amendments, they will be probably consulting soon for 18th edition 1st amendment.
The iet can't even produce a regulation book without errors in, you have got no chance with this topic😂
This is where the book needs updating…again. On the EV course I did, if I had tested on the AC function on the type A breaker I would of failed. Lack of clarification again. I was told to only test type A rcbo’s on the on A and not AC. This is a helpful video but yet again the regulations fall flat on their face.
I do seem to remember that when the type A came out you did do a vidio where you tested the rccd on the AC and the A settings ... I had an NICEIC inspection in July .and we tested a Dorman Smith RCD on AC and A settings. . We could not get it to trip on the A type settings ... I do recall you saying about the manufacturer altering the tripping current on the RCD. So we altered the tripping current on the test meter and this time it tripped fine ... So this may be something else you could do a vidio on especially on this vidio now .. I am still waiting for some information on this Dorman Smith RCD. .
Remember BS 7671 is the minimum requirement John. All the best Gaz 👍🏻
Are MCBs / RCBOs tested for tripping on overload ? At what point do they trip 110% load 120% load or what ?
Again the manufactures are keeping up with current trends. A type to accommodate extra DC loads found in modern installations. Maybe the manufactures could have this noted on each device which tests must be carried out in accordance with manufactures instructions . The regs again are behind and will definitely bring out a new amendment to cover this but only when they need some extra cash to pay the bosses.
Can you cover the topic on putting smaller size tails eg 10mm and 16mm on an 100A main incomer feeding EV boards and such.
Check out this video which is the same kind of situation and the same regs - kzhead.info/sun/daWtc6V5jKKOpp8/bejne.html
@@efixx thanks chaps
I’ve been having issues with a fluke and FUSEBOX RCBO’s when testing on AC 30mA they sent me a load that had been bench tested to rule out… anyone else had this where all I get is a blank screen and the device ripping at ½ 1x & 5x…??
So what are Lewden saying at the start, it's not clear? If you test a type A RCBO or RCD on the 30ma AC setting it will not necsesarily trip with the 0.4seconds? 🤔🤷🏻♂️
If you test an A on the AC setting you should get the result required by BS7671
We have a table for that in VDE 0664-10 which is based on DIN EN 61008-1 and is for the manufacturers of RCDs: For standard RCDs (not the time delayed ones): On AC faults 1x I delta n must have a tripping time of max. 300ms. 2x I delta n max. 200ms, and on 5x I delta n it must be less than 40ms. on pulsating DC currents the current is not 1x I delta n, it is 1.4x I delta n, and 2x 1.4 and 5x 1.4 x I delta n to get the same tripping times. On DC, so type B RCDs, the thing becomes worse: 2x I delta n, 2x 2x I delta n, 5 x 2x I delta n for the same tripping time limits. I don't know what kind of stuff the manufacturers sell in the UK, but here I don't have any issues getting below the 40ms, not even on 1x I delta n. Neither on the AC fault setting nor the pulsating DC test (type A).
Thanks a lot. learn lot
I thought we where going to get the gloves out in the middle of that one, my money was on Shahid
Should we not test to the manufacturers instructions, I’m not aware of any that come with the rcbos. More clarification is needed if we are to test the product correctly.
Do we not trust that the manufacturer has tested the product in the factory?
@@efixx what if it’s faulty, is that not why we test an rcbo!
Do you test MCB’s..? What if they are faulty…?
@@efixx this is a great point from new.
@@efixx Fair point, but MCBs are much simpler devices with no electronics to fail.
The test equipment is giving you the result, it's not telling you if that result is acceptable or not. BS7671 is telling you the minimum requirements for safety, personally I think if the manufacturer makes the thing, and are getting returns that are working perfectly, information needs to be included in the manufacturers instructions, along with installation guidance (ie torque settings), it's one more line of text, something like "when testing the RCD on the A type setting, refer to the 1.4 multiplyer blah blah blah"