How an RCD / GFI works and troubleshooting rogue tripping.
Most modern homes are fitted with at least one RCD (Residual Current Device) or GFI (Ground Fault Interrupter). These are one of the greatest electrical safety inventions in history, but when they start tripping randomly it can be a real nuisance to try and hunt down the cause.
This is where a good sensitive AC current leakage detector can be very useful. In this case I'm using an AMECaL ST-9810 which is a nice simple clamp meter with peak hold that can measure current down to 100uA. It's optimised for tracking down earth leakage current, but also functions as a regular clamp meter too, with a current measuring range up to 200A.
In this video I show the use of an in-line adaptor that allows you to break out the live and neutral conductors separate from the earth for an appliance. It's simply a very short extension with the earth core gently pulled out of the flex and wired external to it. If making one of these I'd recommend that the live and neutral cores are sleeved for protection, particularly if it's going to be rattling around in a tool box or van.
This video also explains how an RCD works and why they aren't infallible and as such should not be used as an alternative to safe electrical practices.
A link to Amecal's website (UK based company) www.amecal.com/
As a electrician I'll always recommend watching your videos. I often get questions about how stuff works from friends and customers and gladly show them one of your videos and here is why: 1. I trust your competence and know that you'll have a good explanation and 2. the customer will shut up, let me do my work and not ask every 2 seconds. You are and always have been such a big inspiration in my life and i am glad / thankful i was lucky enough to stumble across your channel. Thank you!
This video from 6 years ago has made me subscribe today 👍🏾
one of the best videos for non electricians..than you for sharing your knowledge
Thats one thing ive allways liked about you clive, you boil things down to the basic info for learning :-), ive never dug into rcd's but it all makes perfect sense now :-D My distribution box has breakers, then two earth leakage boxes with twisty reset knobs and test buttons, sockets = 1, lights = 1. They trigger at 30mA
😅
I've learned so much from the videos on your channel. I have been a diy electrician for a good 13 years now in the US and all of your information is invaluable! Keep making these videos for us Clive!
Nice to hear Canada isn't the only country with standards boards that invent overly complicated solutions/tests for relatively simple problems. Enjoy your videos Clive, always a good show. Cheers!
When I began watching, I thought this might be pure product placement as you'd been sent the product. I was wrong. A really informative and easy to understand explanation. Thank you!
At the school I used to work at we were given a bucket load of old Fluke clamp meters. Our Cambridge educated head of physics a Phd no less, tested them by putting them round the kettle lead and declared them all broken... So we got given them for the technology department to play with. They all worked fine.
Donald Sayers Now tell us that kettle was turned off and then we know faked PhD. P.S. Selling any of those flukes?
neg he clamped it around both line and neutral. Need to clamp around either the hot/line wire or the return/neutral wire to measure the current. If he went around simply the whip/cord of the kettle then he was clamping around both live and natural and you will not get a reading.
What an idiot and he's teaching? Another waste of the taxpayers money, and possibly dangerous.
@@davidprice2861 PhD enough said.
I was just thinking about some of the silly things that happened in the physics Dept when I was at school.... then the penny just dropped! Hi Mr S :)
I'm happy to see the big fella mentioned the accumulative leakage scenario. I started realising this when we first starting install the dreaded safety switch as they were know then. Now I just use the single module individual RCD on each circuit to mitigate that very issue as we don't use ring circuits in Australia Thanks for the content 👍
Just about the best explanation of RCd and fault current I have seen Go Big Clive :)
That was utterly brilliant, thank you. Explained everything I had failed to understand from all the other videos I have watched, a bit like when I was at college and a plumber finally managed to get me to understand applied mathematics, when a lot of other people MSC's , PHD's had failed. Some people can teach so you can understand and some cannot. You can, thank you. I am suffering a nuisance RCD trip out, that is getting worse. I suspect an old RCD and an old fridge, but it could be something else. I like to do my own trouble shooting before I call in the experts and your video has shown me what I need and what I need to do before I call in an electrician to fix the problem. My Dad, taught me just about everything you shouldn't do with electrical equipment; he was a sales manager for Black & Decker so we had lots of tools lying around without plugs both 24v & 110v. Whilst I always made sure that everything I used at least had the earth wire wrapped round the earth pin of the plug I was using, something I know he failed to do on at least two occasions, but lived to tell the tale, I made sure those lessons were never passed on to my sons LOL. It's just what painters do made me laugh. I spent over 40 years in the construction industry a lot of it in refurbishment.
im a uk electrical engineer. i need to show this to my clients to get them to understand. very well explained.
19:09 - Yes, in that situation there would be a major difference between you and a lightbulb: the lightbulb could be _unscrewed_.
+RFC3514 operative being could...
+Adam Neth - Actually the operative word is _screwed._
I've been using my amprobe for this application for years, well before it was fashionable. Don't put your earths in the same sleeving though when I come to test that short piece of cable I will need to separate them for ring circuit continuity! Well presented video Clive. Well done!
after decades of being an audio tech( soundman) it's great to get the basics explained , so thanks!
Thank you Clive! It's so simple, I finally understand how the breakers and the clamp metter works. That always been very mysterious to me
There is a curseword in German for painters, who are messing with your electrical installation... I learned it during cleaning german earth connectors in walloutlets... "Pinselquäler" which literally translates to person who tortures brushes. Maybe this anecdote brings as much smile to your face as your amazing "it certainly wouldn't feel like you are a lightbulb" brought to mine.
Wonderful Clive. I had no idea there were so many definitions of the word ‘interesting’.
This is the best explanation of how a rcd works and how to test appliances and circuits. Ring main sounds like a fire hazard. I'm from Australia and we use 2.5mm2 for power with a 16amp breaker. love your videos. keep up the good work
I like the Oz radial power circuits but they just can't seem to let go of their rings here.
I enjoyed the ring main description. I kind of knew it, but always nice to have a refresher as I don't do that work nowadays.
First thing when i saw this clamp meter. Need to buy asap.
We are all prone to tripping as we get older! Maybe my nickname should be GFCI.
"In the flesh so to speak. ", I loved that line.
That "ring wiring" ... I mean *goosebumps* ... I saw this stuff on a construction site once. They calculated wether a ring of earth cables for all the houses or two separate strands was more economic (plus if there was need for maintenance or expansion you could work with near to no impact on a ring) But what you describe here ... is just pure madness in my eyes ... way too many factors which could lead to horrible results (fire for instance) ... so yeah ... I am kinda happy with our overregulated system here in Austria. ^^
Love this video. Also the magnet passing through the clamp meter showing current was great. Thank you.
Fantastic Video & Explanation Clive. Keep up the great work. Nick.
About the most useful gadget I bought is the Habotest Socket Tester,very easy to use,and which indicates several faults. I pressed the RCD button to see what would happen,and the whole circuit cut out immediately. I habitually check every socket outlet to ensure its functionality. I have a clamp meter which I have not used yet,usually finding the multimeter adequate for my needs. Very glad to see this video,because earthing has always been a "thing" with me.
I just love your channel - just discovered it and I'm learning! Thanks Clive!
An excellent and very useful video. Thanks for posting this.
Great video! Thanks! It took me a couple of hours to find a N-E fault on one of my ring mains. Which was then down-rated to 20A radial as that fault was unusable (and not wanting everything re-chased out). I'm a DIYer but did it in discussion with my electrician.
Very useful tool, especially for those intermittent RCD trips, those are such a pain to find out where the fault is without good equipment.
Superb explanation, thanks for creating the video.
Great explanation Clive!
Great explanation. always wondered how they work.
This was a great explanation of the RCD/GFI (or GFCI) system. Would love to see a video on the newer Arc Fault breakers. They're code in the US now for bedrooms and designed to detect faults between live and neutral.
+sparkplug1018 I've asked the same thing. I read about 'parallel arc fault' and 'series arc fault' detection on AFCI's. I *definitely* wonder if the 230v is able to 'flash over' more effectively, essentially allowing more fault-current flow (allowing normal MCB to be good-enough for parallel-arc-faults), where 110v might tend to sustaion a more 'resistive' arc or something weird like that........
At the moment AFDDs as they are called in the UK aren't mandatory and I was recently looking up the prices of consumer units, and I made an interesting discovery This is how much it would cost to purchase each type of consumer unit in the UK, not including installation costs Dual RCD, 6 Circuits: £59.99 / €69.27 / $83.72 RCBO, 6 Circuits: £109.99 / €127.02 / $153.52 AFDD, 6 Circuits I am unable to find a pre-populated Consumer unit for this configuration, but the following is based on an unpopulated consumer unit plus 6 AFDDs: £857.69 / €990.59 / $1197.10 RCBO is an RCD combined with an MCB AFDD is Arc fault detection combined with an RCBO
brilliant explainer :) I'm a lightbulb now.
Explained a lot to me. Informative. thanks Clive
Your videos are perfect for my peanut brain, thanks Clive
Hi Clive, I think the max button is essential for RCD testing. Without it, and assuming there is a fault, as soon as you turn on or plug in the faulty device it would trip the RCD and you wouldn't know the scope of the current (32mA or 432mA) - unless the meter has a max feature.
Thank you very much for your clear and informative video. Great Job !
Hi Clive. I tend to design my circuits around radials now rather than ring circuits. If you need a load up to 32A use 4mm2 obviously taking into account installation methods etc. Another great vid. I have one of the clamp meters, had it for years and occasionally it comes in useful for fault finding. Most times a ramp test off load for the RCD will suffice. I like the idea of the test rig. Will make one this weekend.👍🏻
Thanks Clive, I learnt something useful today!
I run a small electrical repair business and find the top trippers are 1. Kettle 2. Toaster 3. Oven 4. Hob The other issue is small leakage so 2 or 3 appliances on at the same time can cause a trip and harder to find. Last on was a oven and iron used at the same time
That was a really useful video. Thanks, Clive.
Good to know I'm not alone in my ideas about ring mains.
That was a very well explained video! Thank you!
Bloody brilliant, cheers for the info it is so timely
I learn so much from your video content, from a wanna be Electrician....
When you're ready, try and get an apprenticeship. Better training and money while you do it.
Great review, I just bought one of these testers on the strength of this very good video
Interesting! I always figured that the Test button just made sure the breaker could move properly; that's a pretty clever bit of electronics.
Brilliant explanation, thank you for your time making this video,
Excellent tutorial! Thanks
Timely advise! Thank you Big Clive. I have some troubleshooting to do around the house and your explanation will help me track down the faults immensely. Unfortunately, that nice little meter has a $50 shipping fee to the U.S. I can find other clamp meters at the local big box hardware stores, but now I know a feature to look for, and have an inkling of how to use it. Thanks again! Thanks for the insight on a test cable too! Looks like I'm going to have a few tasks ahead during the holidays. Such fun! (no pun intended)
+PaulyG10657 The main thing is to look for a clamp meter with a small jaw and low current range that can resolve down to at least 1mA.
So far I've been having trouble finding anything with a range less than 2 amps, plus it seems the lower end ones are only AC rated. Will an AC current clamp meter measure DC current? ~I worked as an electronics tech repairing military grade electronics for twenty years (software engineer now), yet I feel like a complete novice asking a question like that.~ Also, if I might change the topic slightly, is 120VAC @ 2A more or less dangerous than 120VDC @ 2A? (Another 'novice' question...so embarrassing!) The reason I ask is because it seems that some LED drivers come in DC voltages well above 120 VDC, though current limited to specific currents, such as 1400 mA. That allows you to series up to 4 high power (50W) LEDs, which simplifies certain LED configurations schematically, but it seems to me that you trade off safety for simplicity.
+PaulyG10657 Sadly an AC clamp meter will not measure DC current. The AC ones usually use a coil to detect the magnetic field, while the DC ones use a solid state hall effect sensor. AC is generally considered more hazardous than DC because it causes continuous stimulation of the muscles. But even DC supplies can give a nasty buzz if there is residual mains derived ripple on the output.
Thank you Big Clive. In either case, AC or DC, whenever I work with 'mains' electricity I always do so with an over abundance of caution. If I'm working on low voltage low power battery circuits I'm a bit less paranoid, of course.
DC is worse IMHO as it leaves the muscles no chance to relax leaving a vice like grip on a conductor, it does not take AC to continually stimulate muscles.
What a super handy little tool. I think I must have one.
Brilliant explanation
If you can't clamp around the ring you could do it round the meter tails and turn breakers on one at a time.
+mikeselectricstuff That could trick you tho, because there could be just a few milliamps on many breaker circuits. Might aswell just whip out the megger if you're going to trip breakers.
+Vegard S. Right, but if you have a suspect circuit, and you kill all the others, that would give you the result. He meant if the ring is inaccessible..
TBH, I dont get many RCD's that fail due to oversensitivy, but you'd be suprised how many I get that dont trip at all, pressing the 'Test' button is a requirement at testing, most homeowners have never pressed it, a simple thing to check a device that could well save your life. For the record, Im not a fan of Ring finals neither (Not ring mains :P) Love your channel, a recent subscriber but believe me, im working through em. Cheers L.
Great explanation! Thank you for that!
Thanks Clive that was a fantastic video!
"it certainly won't feel like you are a lightbulb" :)
How many Buddhists does it take to change a light bulb? None. Change must come from within!
i wonder if they reurgitate coins at store...
Good gadget! There are also DC versions too... as you say, very useful!
When I saw that meter mentioned in the description I had a look around for it, but at this point in time (and for the forseeable future) I don't see me doing enough electrical work to justify the expense -- it IS a bit spendy. I have on hand here a short extension cord with one of those devices inline. The test button does nothing, so I figured that it wasn't working. Thanks to your explanation of how these things work, I might have to "take it to bits" and see what I can find out about why. :-)
Superb video, all you need to know, nothing left to chance and no silly nonsense
Very good explanation, Thank you!
I really enjoyed your video thanks for creating the content.
You are awesome Love the level of explanation
as an electrician I have found surge suppression devices such as a four gang short extention lead are prone to coursing nuisance tripping. often if the device is on the way out I have found that the variation in supply voltage can make the difference between them making the RCD tripping and putting it on the edge. I have also found high inductive loads such as the vacuum cleaner mostly double insulated can be enough to put a spike into the supply to make a trip go were another fault exists nothing to do with the vacuum cleaner. as for ring mains I absolutely hate them as the testing and fault finding is a nightmare.
+christastic100 Yes! Exactly.... Seen similar with spikes to earth from iffy electric drill, creating similar effects, tripping a "different" RCD to that its' attached to, which has a lot of supression-to-earth stuff plugged into it, probably because of loose earth currents/spikes, going (imbalanced) into L/N of the circuits with the supressors attached... Nice solid earthing, combined with Individual-RCBO consumer units much preferred to minimize these nuisances!!!
Hi, with regards to the non-faulty double insulated vacuum cleaner tripping the RCD when combined an other fault that exists. That other fault could be a Neutral-Earth insulation resistance problem on a final circuit... Imagine that a socket outlet was refixed in a hurry, and the insulation on the neutral conductor became slightly nicked on the earthed metal back box. Under no load conditions, the neutral has basically no current flowing in it. However, when you use said double insulated appliance, the current flowing through the neutral (within in the final circuit), is now shared with the earth conductor (CPC). Thereby, producing an imbalance in the current flowing within the live and neutral conductors inside the RCD, which if great enough (dependent upon the compression fault, i.e. the nick in the damaged neutral cable, which will also deteriorate over time), could cause the RCD to trip. PS. I’ve seen this first hand a few times as a maintenance electrician, so I thought that I’d mention it here.
Thanks, this was a really informative one !!
Really like to see you do AFCI (Arc Fault Circuit Interrupter). Code requires them in residential areas.
+jpalm32 I'm not sure if Arc Fault Circuit Interrupters are required in the UK like they are in the US for bedroom circuits and such. Just so our UK readers know, Arc Fault Circuit Interrupters are designed to detect non-working arcs in faulty wire connections, and broken solid core NM cable (Romex, twin and earth). The AFCI's use sophisticated signal processing techniques to discriminate between a working arc (say from vacuum cleaner motor brushes) and arcs caused by poor connections and faulty wiring.
at the time I am writing this comment, arc fault detection is currently only "recommended", not "mandatory", in the UK and it was only a year or two ago when the UK regulations even started to mention them, and so as a result until they started to be mentioned they were pretty much non-existent in the UK, and although they are now available here, to fit an entire consumer unit with them could easily cost over £1000 (and a basic dual RCD consumer unit may cost as little as £350 to get it installed, and most people in the UK tend to go with the cheapest option, so unless the regulations change from "recommended" to "mandatory", then I cannot see them being fitted in mass, and even if the regulations did change, unless the prices came down, chances are, as most people wouldn't be able to afford them, then they wouldn't get fitted as often, and also, the regulations are not actually law in the UK)
Clive, I had never heard of a "ring main" circuit before and had definitely never encountered them here in the U.S. Seems to me they'd be potentially rather dangerous. As you said, the wire isn't rated for the total allowable current on the circuit. This isn't a problem as long as you have both paths intact to divide the current load across. But if one leg gets broken, you have, as you'd put it, a bit of a dodgy situation. The breaker allows current to flow up to the 32A limit but with only one leg of the loop supplying potentially all the outlets, you could easily exceed the safe capacity of the wire. Seems like a recipe for fires to me.
Fascinating look at your circular circuits. We don't have them in the US but in the mid 1960's, it was popular for the Bell Telephone installers to prewire telephone cable in a house in that manner. The idea was if a wire broke somewhere through the house the phone circuit could still work its way around the other way. Much of that cable was like 24 gauge and could break easily.
+CowboyFrankHarrell We have radial circuits too. In fact a few years back there was talk of them making a comeback. But in order to have the same kind of load as a 32A ring they have to be run in 4mm² cable, which is a bit of a fight to work with in a tight space like a 32mm deep socket back box. The 2.5mm² cable ring mains are run in is a lot easier to use even though you have to deal with two cables at each outlet. Also if you want to add a single outlet to a ring you don’t necessarily have to break the into it - you connect it to the ring as an unfused ‘spur’ using a single 2.5mm² cable.
Nice, the lowest setting on my current clamp is 2 A resolution is 1 mA (it can AC and DC) Thumbs up :) Alex
Great explanation, thanks!
a lot of your viewers are electricians? I figured we were all just here to see cool stuff and learn about lighting :D
There's the added attraction of Clive "getting a wee tingle" when playing with his favourite capacitor dropper lighting power supplies (as a result of missing / unsoldered cap discharge resistors) :-D
I was really here for the cool stuff, but I'm actually learning things.
And the death Daleks
Kaleb White *gay Daley underwear party.
Don't forget about watching stuff blowing up on occasion too.
Thanks for great content . Stay safe.
love your vids Clive. when i wired my parents house as a third year apprentice i did both power circuits as ring mains (thought i was very clever lol) each circuit is on a 20a mcb rcd. didnt know it was actually a thing in england.
England?
Rizwan Ahmed
You my man are brilliant 💪
Hi Clive, I've had real issues with this particular meter and an even worse response from the company. I've tried allsorts of different scenarios and positions etc but Im just not getting the results I expect. In fact some of the results in the 200mA range far exceed the mA trip threshold of the RCD - and thats when testing it on a type A rcd. Ive also tested on type AC and the readings are all over the place. I contacted AMEcal who exchanged the meter after saying it was faulty - however the one they’ve sent ‘calibrated’ is exactly the same results. It took several months to get a reply from the director who then said testing the line and neutral together was not how you do it. After showing him the instructions in the book that comes with it he told me to xxxx off as I didn’t know what I was doing. Then I called straight back and got hold of the ‘test engineer’ who clarified the ones he tested also gives very erratic and unstable readings. All I wanted to do was put the meter around the line and neutral to measure the inbalance / leakage to earth. It even measured leakage with the cpc/ earth removed.
Hi Clive. Interesting video, i was not aware that UK installations was different from the ones in Denamrk, with breakers rated at 32 Amps and loop installation, and i am an elctrician my self :-D In Denmark the Ground fault interupter breaks at 3mA (By law, since 1975), and the lighting groups is rated at 10 Amps, with 1,5 mm2 cabels, with no loop. Also in Denmark, usually there is one 3 fase group, with 3 x 16 Amp fuses, 2,5 mm2 cables, in each household. Love your videos, keep up the good work. Thank you and happy Christmass, from Denmark.
+Morten Rolsing I think the odd "ring mains" thing are to the UK as "wire nuts" are to the US (well, wire nuts, split phase, open carry, the list goes on). Australia has similar wiring conventions: 10A for lighting, 16A over 2.5mm2 for power points, although you're allowed a 20A breaker if the cable isn't covered by insulation. 3 phase is typically available in residential areas, but not commonly connected (only a single phase mostly), except for specific loads like a big-arsed aircon.
RCD's in Denmark switch at 30mA not 3mA
RCD's in Denmark switch at 30mA not 3mA
RCD's in Denmark switch at 30mA not 3mA
Thanks! I had thought GFCI used two torroids and tested the ballance; but I see now one would be much easier to calibrate against itself.
Rogue trippin' sounds like something interesting to explore. Could it include mushrooms? ;) Edit: Really nice explanation of the inner workings of a GFI/RCD, best I've watched. Thanks Clive! :)
Rings are genius, they used to only fit 4 way wylex fuse boards (were talking 50 years ago). 1 way for the cooker, 1 for the lights, 1 for the immersion and 1 for the power - the ring main. This would be on a 30A rewireable fuse, so they would run a whole houses worth of 13a outlets on 1 circuit. Back in the day the standard was 1 outlet per room so this method worked well. Now everyone wants 4 or more per room so we are mainly fitting multiple radials per house/flat, and a ring in the kitchen and utility room
Thanks for breaking it down.
I'm constantly amazed at the verbage used between the UK and the USA.... It totally blows my mind, I find myself watching videos like learn electric and others where they get into all the nooks and crannies of the UK regulations... I'm just glad we haven't gone down the Ring Circuit in the USA.... I'm pretty certain everywhere over here doesn't allow for that, same is to be said about plumbing.... Thou shalt have more than one source to supply 😂
I'm not an electrician so obviously I'd never work on the electrical system in the house, but when I am working on the electrical system in my house I always turn off all the breakers. Because I know I haven't got all of the proper insulated tools and all of the safety training, and sometimes there's a circuit where it's not supposed to be, so it's just safer that way.
Interesting device , I got one recently and have to learn the tricks of usein it etc
Brilliant. Thank you!
Thanks very informative.
Nice explanation
These are excellent.
Very informative. Thanks.
Really interesting and informative explanation, being a software guy, I still think I'm going to leave mains electrics to the people who know what they are doing. 😉
Well explained 👏 👌 👍
Greetings from TX! I just subscribed even though I didn't understand all that you were saying. I'm no electrician, not even an avid DIYer. Certainly not when it comes to electricity. Understand it less and less it seems. But, I am having issues with a GFCI in the main panel box that then runs to a sub panel that then feeds an RV for a tenant. The GFCI trips rather often but not daily yet we've not been able to figure out why. Can't detect any noticeable pattern as to when it trips. Thank you very much for this video. Shed a little bit of light on our situation. Been over a year of frustration!
It could be leakage on an electric heating unit like a cooker or water heater, or it could be a damaged cable somewhere or bridge between neutral and ground. What are they doing at the point it happens? Another possibility is an oversensitive GFCI. You could try changing it.
@@bigclivedotcom Howdy and thanks for responding. I wasn't really looking for advice, just venting I think. We might end up getting rid of the tenant, having other issues with him. Sometimes the GFCI trips and he's not even home in his RV. So it's not something he's actively doing. Could be the 2 window AC units he's always running. But I think this happens during the winter too. This is actually the 2nd GFCI we've installed since the 1st one got some fire ants in there. These GFCIs aren't cheap...over $100 at the local Home Depot. But we might try changing it. He thinks it's overkill to use a GFCI breaker instead of a regular breaker since there's already a regular 50 A breaker in the sub panel that feeds the RV. Isn't a GFCI breaker providing a different safety mechanism than a regular breaker?
@@bigclivedotcom Like you said, it could be a single or any number out of a hundred things he might have running in his RV...and I am no electrician to try and troubleshoot his RV. I just want to prove to him that it is not the GFCI or the cabling we installed. Or if it is, find a way to be certain and find the actual source/cause of the current leakage.
This remindes me of a very interesting story our teaxher told us. Basically he was at a friends house to help with some electricals problems that caused the rcd to switch off when he used his microwave, but only when the lights in the basement where on at the same time. I have to say that I live in germany and some of the old houses here that were wired in the 80s still have 1A RCDs. it turned out that the wiring for the lights was faulty because the lamps where connected to ground instead of neutral. Do when the lights where on there was a current to ground at a bit above 900mA wich worked fine. But once the microwave was turned on, the additional small leakage current of the microwave was enough to trigger the RCD.
I work for one of the electricity suppliers/DNO's and we upgrade the incoming mains, cableheads/cutouts and metering in houses and flats, mostly for council and local housing authoritities. There has been a trend towards some of these organisations rewiring their houses, and because they are complying with 17th edition regs, all circuits are rcd protected, either dual boards with two rcd main switches with individual circuit mcb's, or with individual rcbo's for every circuit. This is all exactly as expected, the problem occurs when these houses have electric heating, usually off-peak storage. Some councils now think they can get away without fitting any equipotential bonding, as they say everything is rcd protected, so no shock risk, therefore bonding is not required. This might be true, if they were replacing the heating consumer units, but in most cases, they are not. Some heating boards are being left, some still only protecting circuits with old rewirable fuses, so the cables are protected from overcurrent and short circuit, but without bonding and EEBADS, there is no shock protection. People like myself, and the companies we work for, have raised this with councils, but they are not all that interested.
+ben kerr virtually impossible to protect against electric shock in all possible cases though. You won't trip an RCD/RCBO when dropping a two-wire appliance in a bucket of water, for example. I guess they don't care about bonding everything when there is no Freezer-only socket, though (considering that some people would still plug in a vacuum cleaner in that socket given a chance).
+ben kerr I've caught the same attitude from electricians "doesn't need bonding, it's all on an RCD". That attitude winds me up no end, I think the 17th edition's requirement for RCDs on everything is a mistake.
Interesting comment. Most cable jointers / linesmen don't know anything about domestic electrics! Yes you are correct but the Electrical industry or the attitude to inspection reports, compliance etc by housing associations and agents etc is a joke just want a piece of paper. I used to get upset about all the non compliances and how blasé people are about it...... I have given up..... They just think you are a jobs worth
The last time I took apart an RCD I found some interesting mechanism for the test button that would be worth a video: Instead of closing some connection there was an inductor wired into the line and the test button would lower a metal tab onto the core of it, closing some short through the inductor, massively changing its inductance and thus causing a short imbalance in current flow
Nice bit of kit (I want one). I worked as an electrician in France for 10 years and got a LOT of critical comments (from the French) on the UK's use of the ring main. A LOT of Brits were coming over and wiring there house UK style. NOT legal here. I had to rewire a number of houses when this was discovered! Still, it kept me in work. :) Keep up the great videos please.
+Eric Gee That would be easy enough. Disconnect ring in middle and turn into two radials, each on their own breaker. I worked in France for a while too. Some other strange regulations. At the time they stopped me wearing a harness in a cherry picker because it was believed it was safer if it started to tip, to grab something and let it go down on its own without you being dragged to your death behind it.
+bigclivedotcom It's not that easy, because here (France), Black can, and often is Live. You could separate the loops and remark(Blue tape) the black wires, but they banned "Twin & Earth" as the Earth wire must be fully insulated here! On the plus side it's warm here (I'm from Sunderland) and the wine and cheese are cheap! Merry Christmas Clive. After saying all that, perhaps "Twin & Earth" is no longer Black & Red!
+Eric Gee The cheese and wine aren't just cheap in France. They are vastly superior to the stuff here. Sadly our wiring colours have been unified with Europe. Twin and earth is now blue and brown. But in the process they changed our vivid phase colours to bland ones. and swapped a phase and neutral colour, which still continues to cause significant electrical accidents.
+bigclivedotcom Thanks for the update. A swear the people who make these changes have never wired a house etc.
+Eric Gee I don't like the L2 phase being black in Europe, it is identical to negative of DC circuits. I do however prefer the new scheme with brown to L1, (black to L2) and grey to L3 rather than the old UK scheme. I would have preferred having L2 purple or any other colour except yellow, red, green, blue or black (to avoid confusion)
It took me fifteen minutes of video until I understood that the rinmin wasn't slang of some sort but "RING MAIN" 😆
Very helpful Clive, very helpful indeed!