Tracing an RCD trip

[@cprfenom]

I know you said its not very exciting, but this is the nitty gritty of fault finding. What I love is that you show that experience teaches you alot, even down to virtually knowing the history of a 40 year old cable was. Great video as ever, so I am now off to barf!

[@dsesuk]

Thanks Chris

[@richardwallace3477]

A good educational video, well done! A thorough test; I would probably have deduced faulty circuit without removing board cover by switching off all mcb’s and then putting them on one at a time until the RCD tripped - maybe I’m just lazy? I would then have looked at anything connected to that circuit and disconnected / unplugged until (hopefully) fault disappeared and then narrowed down to boiler. Glad to see you are now testing earth leakage via tails and not main earth wire; that was a mistake I initially made when I got first got a sensitive clamp meter until I bothered to read the instruction leaflet. Fault finding can be very rewarding or very frustrating.

[@dsesuk]

Thanks Richard. Clocking off the individual MCB's may point you in the right direction if the fault to earth is on the line wiring, but if it's on neutral or if it's a combination of bad IR from two or more circuits, then you need to dig deeper. When faced with a fault situation, we like to test it all before making changes to see what the starting position is, then we know if we're on the right track. Good point about clamping tails, I did show clamping the main earth in one or two previous vids as I didn't appreciate the difference you could see in the reading!

[@richardwallace3477]

David Savery Electrical Services Cheers David. That makes good sense to get a more in depth picture of the condition of the electrical installation. When you say “if the fault is on the neutral..... “ then wouldn’t this also trip the RCD just as with a live earth fault? While I have your attention, can you help with the following scenario: I tested a socket radial the other day and got a sensibly low R1+R2 (it was 4mm T&E) but when I tested the (live test) Zs it was returning a reading off the scale and yet the Ze was only 0.06 -any ideas? or maybe I slipped up somewhere? Maybe I picked a different socket on the circuit that was faulty - it was at the end of a long day, New CU to replace 2 Wylex rewirable boxes and 10 circuits overall with bonding to water and gas to add.

[@dsesuk]

@@richardwallace3477 A fault on the neutral would continue to trip the RCD even if the faulty circuit is turned off at the MCB as current from neighbouring circuits that are still energised will leak to earth via the neutral bar. I'm not sure why your Zs test failed unless the point under test was on a different circuit or the tester was misconfigured. If you've verified the earth fault loop path via a Ze and an R1+R2, then it should check out on a live test.

[@richardwallace3477]

David Savery Electrical Services Many thanks for the reply and now that you explain it, I see what you mean. I’ll look more closely at my non-Zs reading when I return to the job next week. Enjoy the rest of your weekend, thanks!

[@michaelcostello6991]

@@dsesuk Interesting point about neutral-earth fault. Thanks

[@ns4433]

What a guy, humour Witt and knowledge is second to none. Quality dave 👍

[@dsesuk]

Very kind, thank you!

[@adamsmithelec]

Nicely done. I usually don’t get so lucky and end up having to drag a fully loaded cupboard across a carpeted floor to access the plug for faulty appliances!

[@dsesuk]

I hear that. This was a rare easy find!

[@MysticShiv3r]

Nice video David. I'm rather amused at all the Gas Engineers getting sand in their fannies over you removing the boiler cover. We can't help but get a bit of stick being the SAS of the trades.

[@sparkydave2783]

Procell _84 I was also chuckling 😂😂😂

[@tireddad4095]

Great vid. I love watching testing anyway, but your delivery makes it all the more entertaining.

[@TheDeathBonus]

Hi Dave thanks for the video. Fault finding is something only experience can help you with. Hours of theory go right out the window when approached with a nightmare fault and the pressure is on to find and rectify. Love your laid back, humorous style of working. Keep up the good work.

[@dsesuk]

Cheers John

[@ARElectrics]

Great video and thorough with the fault find. I had a tripping issue with a Bosch boiler before now and found it was the on board transformer that had burnt out. Could be anything inside but that was the fault I found. I loved the challenge. Ordered a new one for next day job done. Hope it got sorted. 👍🏼

[@williammartinculleton7523]

I just love your "real world " videos , please keep em coming.🇮🇪

[@dsesuk]

Thanks William. Filming on the job is difficult, but we'll do it when we can!

[@stevejsmales]

Absolutely love these videos David. Retraining as a DI at the age of 51 (you note I didn’t use the E word!)..... great for learning. Just disappointed I didn’t get any new words from this one. Barse is my favourite so far.

[@1987kahil]

Brilliant video mate. Really appreciate the time and effort put in for this

[@dsesuk]

Very kind, thanks!

[@artisanelectrics]

Love the way they stuck the two colours label on with a bit of tape! 😂

[@dsesuk]

Anything can be fixed with electrical tape!

[@no_short_circuit]

Thanks again for another great (and funny) video. As I've said before as a trainee spark, anything on fault finding is a bonus for me. Enjoy the beer.

[@dsesuk]

Ta!

[@jamievaughan6431]

Knock knock..who's there?? Rob the knob bathroom fitter!! 👊👊 😆

[@robmidgley9385]

I'm Rob the sparky not all robs are knobs 😂😂

[@beautifulsmall]

Instructive to see the variation in leakage in different circuits.

[@alanmutlow5854]

Mukgard overshoes!! Sad to notice but they are awesome. No more silly plastic ones ripping every 5 steps or going up ladder.

[@dsesuk]

Nige swears by them. I'm still going through my stock of plastic ones, although I use the tougher kind which go for a good while before ripping apart!

[@ashmanelectricalservices4318]

Well done Nigel, for a minute there I thought you were gonna have hack a hole in the ceiling to access the junction box 👍

[@dsesuk]

We did consider it; easy to hide under a light with a large base, but if that Class I fixture is to be changed for a Class Ii then we need to know what the new one will be like. My recommendation is for a large recessed LED model as they come IP rated, are Class II and would work well in that space.

[@ashmanelectricalservices4318]

@@dsesuk Why is the bathroom fitting not earthed, is there no cpc in the wiring?

[@steve11211]

@@ashmanelectricalservices4318 A lot of older wiring had lighting in only twin rather than twin and earth (aka no cpc). Although the cable to the light fitting has been replaced at some point (Probably when they installed the skylight), the actual circuit wiring is still just twin with no cpc so it doesn't actually go anywhere... Also note class 2 fixture will be plastic and not require a cpc where as that one is metal so the fitting case can in fault conditions become live hence requiring a cpc. Hope that helps.

[@ashmanelectricalservices4318]

@@steve11211 Yes, thank you I'm aware of properties wired before 1970 often had no cpc in flat lighting cable, I just wanted to know if that was the case with this property.

[@steve11211]

@@ashmanelectricalservices4318 look at 12:44 . They say they looked at an inspection that said lighting circuit was not earthed.

[@michaelcostello6991]

Great video showing real problems on site with solutions or problems well explained. Thank you

[@train4905]

A superb fault find sir.well done .I like your humer too.brill.

[@rgtsparky]

Great real world fault finding guys, greetings from Cape Town!

[@dsesuk]

Thanks Ryan!

[@Cjrelectrical]

Hi David what’s the model number on the metrol tester please? I need a second cheap tester.

[@dsesuk]

Hi Chris. I don't know that it's cheap, but mine is the Metrel MI3100S. I think it's the same as the Martindale ET4000, just a different colour case, although the Martindale I believe takes standard test leads while the Metrel has a proprietary connector. I really rate it though, well featured with a great display. Shop around though, prices can vary wildly as you know!

[@Cjrelectrical]

David Savery Electrical Services thank you sir.

[@dsesuk]

Always at your disposal my good man!

[@Jys71208]

This video helped me out on a job today Top man . David

[@dsesuk]

Glad you found something of use among my nonsense!

[@p4ult1]

Great video as always. I love your sense of humor

[@dsesuk]

Thanks Paul!

[@robertgane-howe5177]

Hi David, thouroughly enjoy your videos and watch them all the time. Just worth noting you shouldnt have removed the cover of that boiler unless you are gas safe registered as it is a gas appliance. Just one for noting not a complaint, keep the great content coming. Rob

[@dsesuk]

Thanks Robert, and I know, someone grassed me to GasSafe who had some words of advice. I didn't realise that the case formed part of the seal (or whatever the word is), an that it shouldn't be removed unless the manufacturer instructions state that it's only decorative. It seems strange to me that a manufacturer would make an appliance where the electrical connections are inaccessible to an electrician. We had the same issue again with another site only yesterday, but this time we had a gas man out to take the thing apart so we could IR test the component parts and identify which was giving us an iffy IR. It was the control board in that case, and he replaced it to get us all back in the pink!

[@selfcare8120]

Great video guys and great skills

[@johnnevin5706]

Another great lesson on fault-finding Cheers for this video David

[@bostedtap8399]

Recent problem I had, was due to leaking Y valve ( divert CH or/and HW). Called responsible authority, couldn't find fault on first visit, second visit/new engineer.

[@garyburton2926]

Had the same last week. Turned out to be the boiler for the hot water tap on the kitchen ring.

[@train4905]

A superb job as always Dave and nige.well done Kent's.spot on.

[@Klberts1234]

One of my favourite boards

[@paulbrown9175]

I work in Southern Ireland and you didn't have to necessarily run a earth for lighting circuits until the early 2000s which always seems mad to me, and causes problems when I have to do periodic inspections in rented houses for the local council and a lot of the lights and switches are class 1 fitting and the people renting the house are not to happy when I have to tell them I have to take out there fancy class 1 lights and switches and replaced them with cheap looking class 2 plastic ones. in a earlier video you said you where coming over to Ireland for a break did you have a good time.

[@dsesuk]

Hi Paul. The assumption we would all be using plastic pendants and switches forever seems so quaint these days! I don't envy you trying to convince people that something is wrong when they perceive it to be working right; it's what happens in the event of a fault that they don't appreciate! Thank you for asking, yes the family and I were in Enniscrone in July for a big family reunion. The wife's mother was Irish, and relatives from Ireland, England, Canada and America were among those jetting in from all over for a big get-together. I recall only two things: England basked in a 30C heatwave while we caught some Atlantic weather, and I put away so much Guinness that their share price rose to a new high on the stock market! Seriously though, it's a lovely part of the world and we did have a good time.

[@paulbrown9175]

@@dsesukThanks for the reply, I'm impressed that you reply to me so quickly at 2 in the morning do you ever sleep , I'm glad you had a good time over here, they say the Guinness tastes better over here in Ireland and they are right.

[@thetruth6693]

I feel like Dave is my spirit animal 😂

[@ashvanbro9329]

What was the voltage of the installation residents testing mate you was using

[@Ragnar8504]

Don't think I've ever heard of small-size aluminium wiring in the UK. Are you sure it isn't tinned copper? That was fairly common back in the old days, required for rubber-insulated wires and apparently still done by UK manufacturers in the early days of PVC. The reasoning behind it is that rubber needs to be vulcanised using sulphur and that eats up raw copper so the copper is tinned first. PVC manufacturing is totally different so tinning is no longer required. Apparently these days (introduced about ten years ago) there's ways of producing rubber-insulated plain copper wires but until then rubber flex still had tinned conductors.

[@_______DR_______]

I suspect it's tinned copper, or copper clad aluminium. only once have I ever seen the old Solid core aluminium with the anti ox paste at the terminations, and that was in a house where it was built in the 60s (I think) and never touched. Well until we came and ripped it all out. Was probably the last house on the estate to still have its original wiring, and one of the last in the country to still be using solid aluminium t+e. It seems to be even rarer than rocking horse shite

[@Ragnar8504]

@@_______DR_______ Copper-clad aluminium would be the opposite, red on the outside and silver inside so either tinned copper or solid aluminium if it's silver on the outside.

[@_______DR_______]

@@Ragnar8504 I was just wondering if he had prior knowledge that it’s copper clad aluminium, and wasn’t saying it’s aluminium based on how the conductor looks 🤔

[@spacefx1340]

Worcester greenstar, old gas valve looks like rain water is filling the unit inside you can see the water level, the power cables on the old gas valve use to go with heavy rain...

[@GSHElectrical]

First like 👍. Great video as always David 😁

[@dsesuk]

Quick off the mark there Gaz!

[@rusrus29]

@@dsesuk The swearing adds a great substance off humour also lol ..

[@MartiA1973]

Well that's stuffed my weekend! Thought I wus getting sooo good at this testing an' fault finding' ma'larky. Now find that in less time than it takes me to find their badly labelled board an' whip the cover off - the DS an' N team found the faulty circuit.

[@dsesuk]

Ah, don't be disheartened, it's not always this straightforward! We caught it in the act this time, that's all.

[@JBE]

I'm trying desperately to copy Nigels face fur. Great video David, looks like the bathroom fitter wired that plug?

[@dsesuk]

Don't do it James! He looks like he lives in a cardboard box under an urban flyover and fingers bag-ladies for bottles of meths!

[@ttff6810]

Good video David , very good way of testing to narrow fault, will use that in future , But a Metrel in a fluke box is there a reg about that !

[@dsesuk]

Fluke just make the best damn boxes!

[@ttff6810]

@@dsesuk Ha ha yeah they do but don't let those guys with a Megger know, last thing we want is them trying to stuff it into a fluke box as well

[@dsesuk]

@@ttff6810 My Megger 1552 also lives in a Fluke box! Sorry!

[@superiorbeing95]

In my experience bathroom fitters are meddlers, they fiddle around with stuff they have no business meddling with and half of them don't do a great job of what their job title describes. Plasterboard showers and pondshop light fittings over shower cubicles etc.

[@richardwash6678]

Great video as always. Glad to see you didn't belittle or abuse Nigel. 👍

[@dsesuk]

I'd given him a day off from the abuse, but there'll be plenty of it next time!

[@HeiderSati]

Absolutely brilliant video, thank you very much for spending your time to make it

[@matthaddock6490]

Thank you for another great video David 👍

[@dsesuk]

Cheers Matt

[@PJB71]

Great video as usual, I think I’ll use your methodology of IR testing with everything still plugged in. I have always unplugged everything before IR testing. which in a large property can be quite time consuming. Just like most sparks I am worried about damaging a piece of equipment. Next earth fault I have, I’ll give it try. 👍

[@dsesuk]

It's difficult with a site you're unfamiliar with as you're never quite sure if you found everything, but yeah, L-N IR isn't so important as a failure in insulation there should trip the protective device, so I'm more interested in what's leaking to earth as an RCD trip will affect multiple circuits. When faced with a fault, we want to test what's there before we start making any changes to be sure we're seeing and then removing the cause. I had one 'helpful' customer once who had prepared his house for our visit on an RCD trip issue by disconnecting stuff which meant the conditions that were present when the fault was occurring were no longer there!

[@Clicksystems]

Looks like it maybe leaking internally. Looks a bit crusty around bottom of the valve and the blue plastic on the transformer is slightly discoloured. Would appear that water has got into the transformer on the PCB and that’s where the leakage is occurring

[@dsesuk]

Could well be, those rusty bits were noted, but it's not our area of expertise.

[@richardemery9911]

I have experience of this. 9 times out of 10 it’s the circulation pump. Whether it’s in the boiler or not, sometimes it’s the zone valves if fitted on the system (not if it’s a combination boiler) my money would be on the pump🤞🏻

[@dsesuk]

The heating engineer who turned up had no idea of insulation resistance and no means to test for such, so he part swapped the arse out of the thing until it stopped tripping. I don't know what ultimately fixed it, but I turned up afterwards and verified the IR was back in three digits.

[@train4905]

Exellent job sir.well done.

[@janesouth2943]

That metal lamp in bathroom very unsafe not waterproof either and theres a missing bulb just to ncurage someone to put there fingers into possible live metal case. Did you replace with temporary bathroom light? Dont work on lighting live very scary when it explodes before rcd works. Alluminum thats very old circuit, i ripped all that out at my place, it also had cotton wrap on outside, but was in very good condition made to last. Had the dolly bakerlite switches too from 50s.

[@dsesuk]

We had taken one of the lamps out when we first started looking at it, but you're right, it's wholly inappropriate for that location. We didn't replace it as we didn't have a suitable replacement with us. It's up to the client to decide if she wants to take our recommendation for having it replaced, we have no authority to force her to change it.

[@leebutterworth7465]

Great video David and camera man Nigel

[@dsesuk]

The camera work was cack. I'll be docking his pay.

[@leebutterworth7465]

You actually pay him!! I though it was a help in the community

[@dsesuk]

@@leebutterworth7465 Snort!

[@kylecroft5807]

David love the videos,foooking honest and some jokes in there. I did learn from one of your other videos about sticking the negative of the probe in first and not the positive. I am a epos/Cctv by trade, I don’t go near fuse boards but I like knowing how shit works, ie ring circuits, radials, best practice. A lot of cowboy operators here in Dublin for domestic calls. I’ve never seen them with the proper meters testing circuits. I know in my house there not much earthed being built in the early 70 s. Anyway good videos and thanks for sharing 👍

[@dsesuk]

Thanks Kyle!

[@zamanraja9531]

Bro loving the video! You are helping a lot of young sparks like me man ! 💯 I’ve had an old consumer ( pull out fuses instead of Mcbs; and no rcds) so basically the lighting circuits of ground and 1st floor were wired in together like a ring. So I upgraded the CU first and separated it. However now I’m getting fault on ground floor. Downstairs is kitchen, bathroom and living room. LR is perfect however first thing is there is no live going to the switch ( I havent checked the actual light fitting to see if there is current going there). But even so I am totally baffled as a young sparky why it’s tripping 😅could you offer some help please and some advice on which tests to do?

[@mickspark1677]

Great videos very relatable. Whats the longest you have ever been looking for a fault and is there some jobs where you could not find it

[@dsesuk]

Faultfinding isn't often this straightforward. We tend to book a short amount of time to a faultfinding job (an hour or so), then take it forward from there depending on what we find. If not found quickly, then after some investigation we'll either know we're on the right track and can estimate what's needed to wrap it up, or we'll have an idea of a workaround. The worst ones are the intermittent faults as you have to catch them in the act.

[@michaelsimpson6603]

Great real life fault, you are a top notch spark.

[@dsesuk]

Very kind of your to say so Michael.

[@apbrownelectrical3787]

Good vid that. Every days a school day! Keep up the good work Dave / Nige!

[@dsesuk]

Cheers Andrew

[@sarmisthabandyopadhyay4977]

U saved my new year morning. Thanks a ton

[@OA1998.]

Went linking live and neutral together then testing ir between them and earth, can you not cause damage to appliances, lamps and e.g? Trying to get more comfortable fault finding so any tips would be fantastic

[@dsesuk]

If line and neutral are linked together, then there's no potential difference between them, so you're not zapping your IR voltage across any sensitive circuitry. Unless there's a surge protector or filter between LN and earth, the IR test should cause no issue.

[@OA1998.]

@@dsesuk absolute legend thank you

[@woodyforest7308]

My downstairs plugs are triping nothing plugged in...any ides

[@nw5835]

Going completely off topic, as you drove off it looked as if you passed an old Standard Vanguard car pre 1963 era, much like some of the wiring you come across, great vid as usual.

[@dsesuk]

Well spotted. Whatever it is, it's been sat there rotting away for a good while.

[@doctordoomsnipes]

why do you guys join active and neutral together for an IR test?

[@dsesuk]

We're squirting up to 500V DC into the circuit and there may be loads still present that wouldn't take kindly to it. By joining active to neutral, there's no potential difference between them that can pass across the potentially sensitive electronics of a connected load.

[@johnmilla358]

Great video. This is absolutely the correct way to be gracing back a fault. But in the real world. If it took me that long to find a fault, I’d never make any money

[@jonnywilson9117]

So how do you find a fault then? Guess?

[@johnmilla358]

Jonny Wilson absolutely. Guess and hope for the best 👍🏻. Clever man. 10/10 for sarcasm.

[@jonnywilson9117]

@@johnmilla358 What's the saying, sometimes it's better to be lucky than good? lmao

[@johnmilla358]

Jonny Wilson 😂 oh you lucky man.... bit of advice. Slow it down with the electric shocks. Getting to your head 🤷🏻‍♂️

[@jonnywilson9117]

@@johnmilla358 I was more referencing your way of doing things. You may want to take note of your own advice :)

[@ollieb9875]

More of these! You're too funny. Cheers man.

[@dsesuk]

Hard to get stuff out on site, but we'll try to carry the camera gear more often, thanks Ollie.

[@markg7702]

Great vid as always dave. What did you do about the unearthed light fitting ?

[@millomweb]

Screwed to the floor ? LOL

[@dsesuk]

Thanks Mark. We put it back up and informed the client of the risk; it's up to her what she chooses to do about it, those choices being: book in having a Class II luminaire to be supplied/fitted, demand the bathroom fitter come and make good his mistake, or do nothing and continue to live with the risk. We have no enforcement power to do anything differently.

[@donnierobertson3088]

Great job again like always

[@Longeno55]

You fellas deal with “knobs” doing half assed remodeling too? Same here in the States. People trying to save a buck usually have problems down the road. Cheers! We love your videos

[@dsesuk]

I thank you sir, but this is nothing. The reason we had our camera gear with us today was because of another job we've just spent three days on which has seen a brand new refurbishment without the use of a bona fide electrical contractor resulting in something which looks great superficially, but is bloody awful when you take a closer peek. It may be some time before that one gets uploaded, we're not finished yet and the sheer content already recorded needs some Hollywood-handed editing!

[@JPElectric]

Great fault finding video... I do love a good sweary rant… We have loads of books on regs and code, and guides. I would like to see the DSES guide to electrical terminology. The correct terms, and appropriate swearing, for various electrical annoyances. Such as dropping a grub screw when putting up a heavy ceiling light , Kneeling on a raised floorboard nail Finding the wholesaler has left you one short. RCD fault at 4pm on a Friday A customer who asks you to look at one more issue, after, you have loaded everything back into the van. In an itchy loft, on the hottest day of the year. The realisiation that you have left your favourite side cutters under the floor boards, after you have put the carpets back down, and the double bed put back. Working on a house that was previously owned by a very keen DIY enthusiast. Central heating wiring centre back box lug, won’t grip screw.

[@dsesuk]

Haha! I can relate to all of those, and can nominate a few choice cuss words for each occasion!

[@suzannefahey2623]

Please help my electric went off at 3 in the morning, when I checked the electric cupboard it was the socket fuse that had tripped I tested all the other fuses but it was definitely the socket fuse that kept blowing, what can I do nothing was plugged in at the time to trigger it I just don't get it any advice would be grateful thanks

[@dsesuk]

I'm sorry to hear of your trouble Suzanne. I'm afraid I can't say what the cause is without seeing it. You mention the socket fuse; that could be a breaker, an RCD or an RCBO that's tripping. A breaker would trip if there is an overload fault, an RCD if there's an earth leakage fault and an RCBO if there is either fault. Usually it's down to a faulty appliance rather than a problem with the house wiring, but if the house wiring has been compromised by, say, water getting where it shouldn't or rodent damage, then it could be an issue with the fixed wiring. You need someone to identify what kind of device is tripping, then narrow down why.

[@stevenpearson4045]

why not just switch the rcd on then turn each breaker on till the rcd trips to find what circuit is faulty ?

[@dsesuk]

Because if the fault is on the neutral then switching on a healthy circuit can still cause it to trip, the load from that good circuit leaking back through the bad circuit's neutral and down to earth. It can send you in the wrong direction. Also, there may be more than one fault which is having a cumulative effect on the RCD or an intermittent fault not present when we're there. If we test all circuits, then we know which we should be looking at, and if problems still occur we can compare test results if we're called back to see which circuit(s) are showing fluctuating readings.

[@stevebell6057]

Because then he wouldn't be able to play around with his (expensive) toys - and rack up his bill (while rifling thru his customers belongings).

[@BrianRS172]

@@stevebell6057 looks more like a thorough and proper job to me.

[@harrypotter101000]

Great video 😂 educational and entertaining

[@dsesuk]

Thanks Kenny

[@LAsparkTVWireTestLimited]

Excellent video. Can't believe you bothered to take a reading on just the boiler cable, I'dve stopped soon as I realised it were the boiler. You're so conscientious. What an amazing find on the ceiling rose loose connection. Brilliant work, like watching a couple of brain surgeons. How much time, I wondered, did the video cover, before getting wankered!! Spellcheck don't like that word by the way.

[@dsesuk]

Thanks again Mr Y., although some of this may be more luck than judgement; the loose connection was a jammy find as we were convinced it was going to be a gnawed cable we'd never find without busting out the ceilings because the client said she'd heard something scurrying about above! The loose connection may have been overlooked based on that assumption had we not disturbed that point by sticking a camera up there!

[@LAsparkTVWireTestLimited]

@@dsesuk It's an amazing channel N Bundy's favourite too. I love the ease of your presentation, keep it up I know it's sometimes a pain filming stuff when you need to chop on. All the best ttfn

[@jagdtigger]

Does it matter for the RCD if the phase and neutreal are switching places? (I have a small shed where i maintain my bikes and the only means getting power there is a extension cord so IDK where the phase gonna be.)

[@dsesuk]

An RCD is not polarity sensitive, and many manufacturers either don't label the terminals, or they label them as 1, 2, 3 and 4 instead of Line/Neutral in/out. That said, if your RCD is explicitly labelled, then by not following the labelling you wouldn't be complying with how the manufacturer intends it to be installed, although it ought to work just fine nonetheless.

[@jagdtigger]

@@dsesuk If i had any way making sure it would be the proper polarity i would do it, but in this situation its not feasible. The device only has explicit markings for neutreal, 1 and 2 for the phase: www.mentavill.hu/_upload/images/catalog/423005/423005.jpg

[@TheDefpom]

Very interesting, thanks.

[@dsesuk]

Ta!

[@p166mx]

Blimey I thought our electrics were old, (1980) but at least the it is in copper PVC and the lighting circuit is fully earthed. We do need to get that 1980 Wylex united replaced though! What worries me most about this video though as we also have exactly the same boiler we have just paid a fortune for at it looks like cheap crap inside :(

[@dsesuk]

1980 is thoroughly modern compared to some of the things we see!

[@p166mx]

​@@dsesuk my only worry is we did have an issue with quarrels, so I hope they haven't chewed through any cables but hopefully an insulated and earth leakage test will confirm that the wiring itself is ok before we get the consumer unit changed. One concern I do have is none of the ring final cables are clipped to the joists, they are just hanging loose under the house was that normal back then?

[@dsesuk]

It's not unusual to come across non-clipped cables, and them dangling under floors generally doesn't cause them any harm so long as there's no undue strain on any part of the cabling.

[@kiewong4870]

You’re putting 500v down the live and neutral, not turning anything off. Couldn’t this damage equipment, which is plugged in?

[@dsesuk]

It's possible, but I've not seen it happen. With a voltage applied to both line and neutral, the potential difference across them is zero... unless there's a switch on the line that is open or a broken conductor. Remember that IR testing in this way is exactly what happens in a PAT test, and although the code of practice for such lists this as a 'hard test' which can be omitted if a risk of equipment damage is perceived, most people who perform PAT testing including myself undertake such on common household or office equipment without worrying too much and without leaving a trail of destruction behind us. Manufacturers know equipment will be tested, and items around the home aren't likely to be too troubled by it.

[@kiewong4870]

David Savery Electrical Services cheers Dave 👍

[@mark90229]

Another great video 👍

[@dsesuk]

Cheers old sport

[@deanhenry14]

Would you mind explaining what you meant by "floating earth" while you examined the bathroom light? Cheers! Great video guys👍

[@dsesuk]

Hi Dean. I just meant that the CPC at the luminaire wasn't connected to anything, or if it was, it wasn't a good path to the main earth terminal back at the source of the installation.

[@Stevo3032]

Could anybody explains how a megger/insulation resistance tester works ? With a multimeter you're measuring the difference between two points. Is this the same with a megger ? Cheers

[@dsesuk]

An insulation resistance tester squirts out a DC voltage down one probe, usually 250V or 500V for the work we do, then it detects if any of that voltage is picked up by the second probe. It allows wiring to be 'pressure tested'; a straight continuity test will show if there is a dead short, but if there's a breakdown or compromise of the insulation, then what you have is a high resistance path that won't be picked up by a continuity tester. Although that path is high resistance as far as the continuity test is concerned, once you energise that circuit, that resistance can break down allowing current to leak to where it shouldn't. By squirting a high DC voltage into the wiring, we can force a breakdown and detect if there is a problem without the circuit being energised. If you see what I mean!

[@doosraification]

What is the make of that inspection camera?

[@dsesuk]

The Ferret WiFi, available at CEF. I did a video on it back around April. Jolly useful bit o' kit.

[@leebutterworth7465]

I got hold of a rather nifty WiFi inspection camera from Amazon for less than £20

[@filfan2001]

You’re having a similar week to me. Had a call out today where the whole house was without lights due to a loose neutral in the 1 working light. At least you didn’t have the benefit of the customer re wiring the switch but saying he hadn’t 🙄

[@dsesuk]

Ah yes, being thrown off track by not being told the full facts! Mind you, here we were thrown off track by the client saying she'd heard things scurrying about in the ceiling as we jumped to the conclusion that it would be a gnawed cable and started getting busy with the camera. Doubtless there are some pests up there, you can see the droppings on the camera, but the fault itself was simpler than expected!

[@ashmanelectricalservices4318]

I think you're within your right to add a 'Lying Bastard' charge to that invoice.

[@DavidBerquist334]

Is the rcd like the ground fault here in 🇺🇸 usa i like the gfi outlet si if it goes bad you dont have to go threw a whole circuit consult codes before working

[@dsesuk]

Yes, an RCD is a GFCI. Goodness knows why we call them Residual Current Devices, it seems to me that Ground Fault Circuit Interrupter is a better and more descriptive term.

[@DavidBerquist334]

I do wiring here in the us in England i hear red is live black neutral green ground 14 gage and 12 gage is what we use 14 gage on 14 amps close to 1.5mm 12 gage is close to 2.5 mm germany uses black live blue neutral yellow green ground is england on mm wire or gage In Saudi Arabia the outlets look like they take american plug and they do but looks like it wires like a British outlet on the back and goes on a British box and i hear they use awg american wire gage wire and black live white neutral green ground like 🇺🇸 thanks

[@dsesuk]

We're metric for wiring here so the CSA is in millimetres, usually 1.0 or 1.5mm for lighting, 2.5 or 4.0mm for sockets, 6.0mm for cookers and 10.0mm for electric showers. Old colours were red and black for line (hot) and neutral (single phase), or red, yellow, blue for three-phase, but around 2005 we harmonised with Europe who are brown and blue single phase and brown/black/grey three-phase. Really old colours used a dark green for earth, but that fell out of favour as in poor light it could be mistaken for another colour, so green/yellow is now used with a 70%/30% split, so some earth cables are mainly yellow with a green stripe, others mainly green with a yellow stripe. It would be nice if, as a species, we could have standardised more on colours, voltages, outlet types and terminology more. Any alien race who visit us in the future will think we're mad. If they're intent on world domination, they'll have a hell of a time buying adaptors so they can plug in and recharge their ray guns as they go around the world!

[@DavidBerquist334]

@@dsesuk 4 mm is it solid or stranded i hear they do ring circuit from breaker threw all outlets and back to same breaker is that to minamize voltage drop

[@dsesuk]

4mm is stranded. Ring circuits are in widespread use, but not for voltage drop, rather they're a throwback to WW2 as copper was in short supply. They allowed a house to have only one or two socket circuits rated at a higher current (30A fused or 32A breakers) rather than requiring two or three radial circuits each rated at 15-20A thus saving on wiring. The ring configuration allows thinner cable to be used, 2.5mm usually, but because you have two paths from the breaker, the CSA is effectively 5 sq. mm. Sadly, even after copper became readily available again, the ring thing stuck and new houses are still built with them today. They're fine until Joe Homeowner comes along and makes cack-handed modifications leaving the ring broken and an undersized cable at risk of carrying a current it wasn't rated for while the breaker sits there happily doing nothing. Personally, I don't like them, and when rewiring a property we tend to install radial circuits. The high current ring is also the reason why UK plugs all have fuses in them as a 32A breaker wouldn't be much protection for an appliance flex in the event of a short circuit. Plugtop fuses come in 3, 5 or 13A flavours generally and offer localised protection for any given appliance.

[@CAR_SOLUTIONS]

What are the consequences of having no earth on a metal light fitting and switch isn’t that a cause of fire if something does go wrong within the lighting circuit

[@dsesuk]

It's not a fire risk, but the job of the earth conductor is to provide a low impedance path for current to travel down in the event of a fault. As an example, if the line wire pops out of the connector on the rear of that fitting and touches the metalwork, that sucker is going live, and someone touching it is likely to get a shock. Whether it kills them or not depends on a number of factors. If there was a working earth in the thing, then the current will travel down that rather than through the higher impedance of a human body, and the fault current shorting line to earth will also cause the breaker to trip cutting the power.

[@CAR_SOLUTIONS]

David Savery Electrical Services I see that makes sense thanks for explaining that keep up the good work 👍

[@gavindebrito7117]

David you are a Legend! "I will eat it tonight and you can smell it tomorrow "😂😂

[@dsesuk]

Gutting that Nige is off tomorrow!

[@norfolkmustard]

@@dsesuk And a bank holiday on Monday ;)

[@dsesuk]

@@norfolkmustard Damn, I can't keep it in until Tuesday!

[@Chris-um9ds]

great tip looping the line circuits so you don't have to unplug everything !

[@dsbelectricaldavidbetterid8448]

i do the same test its a brilliant time saver i test on 250v dc tho

[@dsesuk]

As it's tripping, we want to catch it in the act before modifying anything, so we don't want to switch off or unplug stuff when we first arrive, we want to identify what's bad, then break it down. By linking line and neutral, we can test without damaging any connected appliances even at 500V as the potential difference being zapped up line and neutral together is zero.

[@Chris-um9ds]

@@dsesuk that tip will save me hours Dave , thank you .

[@gordonLP]

@@dsesuk Wouldn't 500v be a problem even with LN joined if there were any surge protected extension leads/devices on the tested circuit? Regards, Gordon

[@ashmanelectricalservices4318]

@@gordonLP That's why he also IR tested at 250 V, if an SPD was in circuit, the IR reading would be high at 250 V but low at 500 V.

[@phillipcarlroberts4640]

Great vid and its typical of an electrician not to have a plug in the toolbox.

[@dsesuk]

Need to restock the van!

[@phillipcarlroberts4640]

@@dsesuk there will be one in the morning...We all understand that : )

[@dsesuk]

Actually, that should have read 'need to clear all the accumulated shite from out the van, then figure out what needs restocking!'

[@phillipcarlroberts4640]

@@dsesuk Wow a simple conversation where you have proven that you actually are an electrician without providing any documentation, seriously though my comment was just banter.

[@mastergx1]

Please tell me you changed that unearched light - or at least discnnected it and made safe. You know the customer isnt going to give a toss once you've gone

[@rattlehead85]

What was the customers response when you told her her class 1 light fitting needed replacing with a poxy class 2 fixture or she needs the circuit rewired. 😂😂😂

[@ashmanelectricalservices4318]

You can get fancy Class II light fittings but they tend to be a lot more expensive. Class II downlights is another option.

[@dsesuk]

She hinted that she plans to move, so I suspect nothing will be changed and it'll be something the next owner takes on. Mind you, they may decide to refurb the place in which case it might be rewired - we did the house next door last year.

[@JOSHIMEOW]

Just thought I'd ask a question, if your not allowed a class 1 light fitting why didn't you disconnect it and install a class 2 fitting. You called the bathroom fitter for that!!!!

[@maxmerton]

Steven richardson , you can’t just go rectifying every unrelated breach found in a property. The property owner had a PIR, so it’s down to them.

[@dsesuk]

The installation of the Class I fitting is someone else's cock-up, it's not for us to put right for free, neither do I happen to have a suitable Class II luminaire on the van. We weren't called in to look at the light remember, it's incidental. As there's a cost involved because a new fitting needs to be sourced and installed, it's up to the client to decide if she wants to pay that cost or to shop around for other quotes. We're in no position to legally require her to pay for us to replace the light, to replace the light for free or to disconnect it entirely. All we can do is make her aware of the risk: she then has to decide how she wants to manage that risk, whether that's arranging for replacement, demanding it be put right by the bathroom fitter or simply going on living with it; these are all her choices to make, not ours. Some installations we walk into and can see a whole host of dodgy workmanship from other installers. If the expectation were that we righted every wrong we came across, we'd never be able to stick to our schedule and we'd have customers complaining that we're overcharging by undertaking additional work they hadn't booked us in for. We're only authorised to do what the customer tells us to do.

[@zu1875lu]

@@dsesuk wouldn't bother explaining yourself to an obvious dumb question...

[@JOSHIMEOW]

@@zu1875lu you replied lol

[@ashmanelectricalservices4318]

I am curious as to why you took two MFT's off the van David, I know the TIS both measures earth leakage and IR testing, so why take the Metrel off the van?

[@dsesuk]

As it was a nuisance trip job, I only went in with my Fluke case as that contains all I generally need. I could have measured the leakage with a clamp meter I also keep in that case, but I thought the TIS might be more interesting to look at for the purposes of this video as that clamp accessory may be too expensive and tricky to get hold of for most to bother with. We often have both out on a job though, one by the board, the other at the endpoint so we can test what we need to test without too much running around!

[@ashmanelectricalservices4318]

@@dsesuk Alright for some aye, two testers out on site... My Megger 1720 MFT has been sent away for repair so I'm stuck with Craptech KT63 which bins your results after a couple of seconds or when you disconnect from a supply 😭

[@dsesuk]

Oh dear, I hope that gets sorted out for you soon old chap. I think Nige has a 1720, we just never bring it out on site. Maybe we should in a future vid for some variety! Haven't used the KT63 but I thought they were well rated(?)

[@ashmanelectricalservices4318]

@@dsesuk I've been using it for a couple of days now and miss the creature comforts from my Megger 1720 such as 2 lead loop test, constant continuity measurement, auto start loop test, faster auto RCD trip test... I'm gonna stop now, the more I recite, the more depressed I get.

[@dsesuk]

Chin up Alvin, it's a bank holiday weekend and the sun is shining!

[@johnyearsley7970]

Brilliant/ love the video/ funny . John

[@serenetysteel7007]

Great vid! Nice one

[@dsesuk]

Thanks again!

[@msanwer637]

What is the name of this wire checking machine

[@dsesuk]

The blue unit is the Metrel MI3100S, while the red/grey tester which does the same stuff is the TIS MFT Pro.

[@MARTINA-gc3tq]

did you check the boiler socket outlet?

[@millomweb]

For what, toast crumbs ?

[@R.H.Electrical]

Another great video. The "shes hit us with the while your here" so relatable lol Keep up the great content

[@The160879]

Outstanding stuff

[@dsesuk]

Ta!

[@stevendouglas3860]

What brand are those Teal VDE screwdriver

[@dsesuk]

They're Hager's and were sent to me following an online promotion they ran on Twitter a couple of years ago. They're badly worn now and have lost a lot of their plastic insulation from being poked into places they weren't designed for. I'll have to replace 'em soon!

[@stevendouglas3860]

@@dsesuk Thanks David .

[@mickspark1677]

Im still learning about electrical work so it may sound obvious to you but how did you know it was a fault to earth and not the live and nuetral

[@dsesuk]

A breakdown of insulation line to neutral would cause an overload fault and trip the breaker. The RCD will trip when current leaks to earth, so we knew it was an earth fault we were looking for. We didn't narrow down if it was line to earth or neutral to earth, but that's for someone else to figure out!

[@mickspark1677]

Thank you very good videos you will be surprised how much you learn from videos like these. Thank u very much

[@dsesuk]

@@mickspark1677 Cheers Mick

[@DerekHundik]

why you just dont isolate the MCB that cause the tripping ?

[@dsesuk]

It depends on whether the fault is on the line or the neutral as switching off the MCB doesn't disconnect the neutral so the RCD can still trip. We could disconnect it at the board, but as this is a fault with an appliance, and one which can be unplugged, there's no need to isolate the circuit.

[@DerekHundik]

@@dsesuk i know that it doesnt im talking about faulty circuit. So switching all off and then switching them back on one after another you know which one is causing problem. If its ring you seperate one leg from another to narrow the fault area.

[@dsesuk]

@@DerekHundik Not necessarily as even with the faulty circuit off the RCD will continue to trip if the fault is on the neutral as it's commoned to all the other circuits. We've seen it before where switching on a healthy circuit causes a trip just because the surge current from that circuit caused a leak via the bad neutral of a separate circuit which is the one with poor IR. The trip may also be down to poor IR over two or more circuits having a cumulative effect on the RCD. We test all RCD circuits at the start to see what's reporting as bad so that we know for sure where to be looking and that all faults are accounted for.

[@DerekHundik]

@@dsesuk yes so you narrow it to the possible fault circuit and then test one or two. I dont see the idea for disconecting all the circuits.

[@dsesuk]

We test all just to be sure we're not going to get any call-back for the problem still happening. We know with these numbers that there was just the one fault there and it ought to be stable with that appliance removed. That's also why we write down the readings we get from each circuit on the day; if the client says there's still an intermittent trip problem, we can re-test and compare results to see if any other circuit is unstable or inconsistent.

[@metalman4141]

Great work 👍

[@dsesuk]

Very kind, thanks Matt

[@Webbster77]

Nice vid mate... where did you get the link croc clips from?

[@dsesuk]

Thanks again Derek. The crocs were from Denmans I think. I believe they're a Kewtech product and they came as a pack of four (two short, two long).

[@dsesuk]

Derek?? Sorry Tony!

[@Webbster77]

David Savery Electrical Services ha ha ha!!!

[@Webbster77]

David Savery Electrical Services you had what you call a brain fart! 😂

[@dsesuk]

Wasn't the first, won't be the last!

[@petertallowin6406]

Instead of brewing your bum chatter, send it to him via air mail. Signed, sealed..... Ahhhhhh. Delivered. Ohh... scotchy. Brilliant video as usual.

[@dsesuk]

You're suggesting I fart into a Jiffy bag and pop it in the post?

[@petertallowin6406]

@@dsesuk or an IKEA zip lock bag, either would suffice.

[@dsesuk]

I'll get right on it!

[@edwardgadsby8327]

What are the chances of a small PAT testing video David?

[@dsesuk]

Not a bad idea old chap. Will put some thought into it!

[@Arachnoid_of_the_underverse]

He may have to employ a new man named Pat first and then do some validity tests such as can he make a decent brew :D