Fault Finding RCD tripping - Electrician 

Hi boys, Even though the leakage current goes right up when the shower is turned on, it doesn't necessarily mean that the shower is faulty as there could be a resistive neutral/earth fault say, on another circuit/s or appliance, and which the neutral current backfeed from the shower is now finding, as the neutrals are commoned together. What you should have done at that point is insulation resistance testing on the circuits separately, L&N - Earth to confirm which circuit or circuits are leaking the most current..

Ideally when testing the RCD all loads should be removed. Reason being if the loads/circuits are producing say 10mA of leakage in normal operation (say damp cobwebs in a ceiling rose), then your ramp test, which implied that the RCD trips at 21mA, actually demonstrates that it requires 31mA to make it trip. ie 21mA from your tester plus the 10mA from the loads.

Absolutely fantastic description of earth leakage. Keep doing what you do everyone is loving your content.. Adam is one lucky lad who is getting a fantastic apprenticeship. 👍

Always leave the cpc connected to the earth bar when testing insulation resistance between live conductors to earth .

No need for fancy pat testers,your megger will do the insulation tests and measure the earth impedance.And a short extension lead wired in singles is much cheaper than expensive "special" leads to get your clamp meter involved.

Why didn’t you turn the board off first…?? Live to earth then neutral to earth IR tests. If you have low readings Then start to disconnect individual neutrals to find what circuit is dragging it down. Don’t worry about you clamp meter yet. IR it first ….. keep Adams fingers out of a live board 🤣💥🔥🔥

I'm leaning towards a resisitive neutral to earth fault somewhere (either in the fixed installation or in an appliance). As current demand rises, the potential difference between neutral and earth also rises, driving more current through the fault. Certainly an insulation resistance test from neutral to earth on every circuit is in order. This should be done with the CPC still connected to the earth bar as a fault could potentially exist between the neutral conductor of one circuit and the earth conductor of another, or between a conductor and a pipe.

Brilliant Guys as always love seeing the testing as this part is never shown and should be as I think a lot of sparks if there honest could do with more help on testing, so great watch guys keep it up

"That's what your mum said" LOOOOL Nick, I love the relationships you've built over the last couple of years. Shows nothing but strength. Well done for building up your team

Great video as usual thought the following might help.Fridge and freezers need motor running and door open for light, washer needs to be on a hot wash so elements and motor running.ovens/ grills / hot plates need to be heating up , over ride outside lighting so they are on.

Spent a challenging day trying to track down an intermittent RCD trip in a family member's house, doing various IR checks on final circuits - turned out it was a N-E fault in a 4-way extension socket. I'd left it plugged in with the socket outlet switched off but, of course, the switch is single-pole on the live conductor only so the fault was always connected - D'Oh! Note to self - unplug everything when investigating intermittent RCD operation. Also have intermittent RCD tripping on the distribution board in our house - can go months between trips or sometimes trips three times in one evening. It's an older installation (from 1994) with 100A RCCB main switch. Despite investigating and testing I've never tracked down the source of the problem. Current theory is it's down to the inverter drive for the 2kW air source heat pump in our garden 'pod' which may occasionally pull enough harmonic current to push the prevailing or 'standing' leakage current just high enough to be seen as a fault by the RCCB. Board is getting replaced this year and new board will have RCBOs fitted so at least I can narrow down the offending circuit - maybe.

Good video lads, I love fault finding, you just have to take a step back and think through things logically. Also it doesn't help when the customer is breathing down your neck!

Been doing similar tonight until 9pm! Split the ring after unplugging and Ir test carried out. Found side the fault on and work from there; disconnected run cable both ends and fitted 2 x B20 mcbs

Replace shower & recommend complete PAT of all appliances. In installation, I normally use at least 2 radials for kitchen sockets & individual radials for appliances such as washing machines, tumble dryers.

Just an add… I try not to use “nuisance tripping”, especially in front of customers or general public. DIYers will happily short out a trip if they think it’s nuisance tripping. Either the trip is faulty (sensitive) or not. Circuits with transformers on (even class Ii) can cause tripping too.

Great work and thanks for sharing this with us take care

Good approach @ the beginning, ramp testing the Rcd. The next step for me would be pulling all plugs out from ring main.. then an IR test on circuits most probably @ 250v, obviously with Main Switch off😎

just unplug the lot turn all the breakers off and disconect the neutrals . megger the lot and the faulty circuit will show if its on the fixed wiring . and what circuit is causing the fault. a 15 minute job . if its on the ring part the wiring at furthest point in a socket part at db and leave the faulty leg out and reconect the rest then part the faulty leg in the middle and narrow it down once found possibly a trapped neutral to earth in a socket reinstate all of the circuit job done

Hi Guys, when testing ring main circuits if you do a continuity test first (little r1 rn) etc first it will confirm you have a ring circuit and if there are any resistive loads I.e. something still plugged in, you can then test one leg of the ring rather than struggling to put both ends in the crocodile clip, you should also leave the CPCs connected to the MET when doing the IR test it will give you a better chance of finding IR damage when it has a path to the general mass of earth. Great video thanks Simon SRP Electrical.

The other thing with rcd is that they can start to wear an become too sensitive an trip sooner than they should. Nick link out live an neutral together an do the other lead to earth then if you miss something plugged in it shouldn’t affect it

Tumble dryers, especially condensing ones - and worse still closed air circuit ones can be quite bad for leakage because they blow damp air over the elements, a badly fitted filter results in bits of damp fluff bridging from the element to the frame across the mica sheet.

You both did a great job.

Was there an rcd in the economy 7 board? Test it and if it’s stronger and swap it over just to see if it makes a difference as it’s the same make?

thanks. those clamp meters are ace

I had a fault, started of monthly, went to weekly, then daily. One T&E, between sockets was run through the foundations. I had an extension fitted which loaded the wall and pinched the cable. Would pass a megger test, eventually found as daughter stood on the right place as I was testing. 6 months to find, board changed to a RCBO one to find the circuit. Cost heaps to fix!

PJD - BEST explanation of what should be bleeding obvious

21ma is fairly common for square D/schneider RCDs/RCBOs ever new iso bar P ones

You know what grinds my gears, U.K. and EU specs for appliances both state that any capacitors should drain down within a certain amount of time when the units switched off. But my Bosch washing machine gave me a lovely little capacitor shock (and a loud snap) when I touched the plug with it while it was unplugged.

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?

Great video guys 😎

Keep an eye out for the "NEW" washers that are DC Drive - when they strat to spin & rev up they can sometimes trip an AC type rcd / Rcbo

A fridge compressor is not alway on but i can trip a mcb its a sneeky device 🤫

Great Content guys , Has a new Sparky learning this really highlights the Importance of quality work . And in this case it really Bad, ‘ serious stuff is electric ‘ Somebody home end of the day . And when you come across these type of jobs how will you price this . And Decide if you do need to rewire this to make it safe .

Are those tails to that board over 3m from the Isolator? It certainly looks like it?

Had a very similar fault last year, ended up to be a fault with the microwave, then it failed. Microwave replaced and no faults since.

13:30 I spent some time looking, and noticed that not all of the lamps were switched on at the kitchen lights, but is it just shadows, or are those heat/burn marks on the ceiling directly above the lamps? Fairly convinced it's not shadows.

Yaaas! Get amongst it!

Will be needed a 3 bedroom semi rewire soon How long would something like that take. Would the travel to liverpool be worth it.??

Rcbo's are only any good if they are DP ones (double pole).

Good video and exactly what I would do 👌

Has Adam not got a TIS MFD? I’d be interested what tests you can carry out with that as I’ve just purchased the TIS Pro. 👍

How do you go about pricing for situations like this in the video?

PAT tester is great during fault finding.

Well done nice job it be honest with you you make the problem is big . Forget all this how much you charge the customer.

👍👍nice work 👍👍

That first advert was placed perfectly with the trip 😂

Fault finding by yourself is a horrible experience. You really need a buddy to keep you balanced.

14:25 the only thing I can think of with 'been in the attic' would be they disturbed bathroom extractor fan?

Had a spurious trip that would never show itself when you wanted it too, turned out to be the door on the dishwasher.

I've not used the clamp meter in this way before, just trying to understand how you are measuring the loss in milliamps. Rcd monitors earth leakage but you have the clamp around neutral and live together. What setting is used to distinguish between flowing current and current going to earth.

I think you’re looking in the wrong area . I don’t believe it is the shower that’s the problem. You have a low insulation resistance between N-E on one circuit that when a high load is turned on ups the earth leakage by back feeding down the neutrals . Your putting to much trust in the earth clamp rather than the best tool in your arsenal insulation resistance testing .

Great video guy, question why does Adam have to change what he says at the beginning of his ones when you end yours with an ace venturer saying 😂😂

A: Want me to hold the bush back while you film? N: That's what your mum said... You snuck that in quietly.

Good video lads 👍🏻

That CU is bloody horrible , looks like something they have in India or new Zealand , Great process of elimination , Great job well done . Fantastic video as always Nick and Adam.👍👍👍❤️

We have a saying in norway: -alot of small creeks, makes a big river. Every appliances create a small earth-leakage. With one 30ma comman RCB for the entire innstall, it sure can cause tripping without any actual fault on the innstallation. Start useing bigger boards as standard in england for expansion or use combined RCB/MCB

Fook the haters, say what you like Adam. If people don't like it, that's their problem.

Love the fault finding video content and everyone's different approach to finding it and a solution. Good content. After all ir tests then I would have gone for a single rcbo for the shower circuit if available for the board. Id be interested to know what the result is once the shower is replaced . Could be coincidence but started after someone was in loft , either disturbed shower cable or disturbed bathroom light/extractor. Keep up the good content 👍

With the earth leakage going up and down with loading I’d guess a N-E short on one of the circuits, maybe try a global L&N to E IR test and if it’s down separate the circuits out and do them individually

Wow nick, you’ve lost some weight buddy 😃 thought I’d clicked on an old video😂 You good job!!

Spent hours chasing a fault around that when your there doesn’t exist, as soon as the van pulls up outside home the fault will return 😂😂 every time

So your saying if a trip isn’t instantaneous it’s probs gonna be an appliance?

I’ve got a Class II Bosch GAL 18V-40C about 18 months old that sets off RCDs but works fine on non-RCD circuits 🙄

From this we can tell Adam does all the cooking in his house :)

I hate those old consumer units with an RCD that kills the whole house. My house had a wylex board from the 80s with a 100ma rcd. It would nuisance trip all the time. No obvious faults and getting a replacement RCD is abit of an unknown. Glad i changed it for an RCBO board that gives me no agro

Thanks. For. The. Video It's a very. Hard one. To. Fine For. Sure

You have a fault to earth somewhere downstream of the RCD, as any and all loads applied raise the leakage current. It could be on ANY of the circuits downstream of the RCD. IR test each circuit until you find the bad one, then start breaking that circuit down till you find the fault. Oh, and keep the CPCs connected to the earth bar while you do this, and IR test to that. The fault may be to 'real earth' rather than the CPC, if you see what I mean.

Question for anybody here who feels like answering😄, what’s the difference between an IR test at 250v compared to 500v, is the 500v much more likely to find an IR fault than 250 is? Or would the likelihood of finding a fault be similar in most situations. Thanks 👍

Also make an appliance earth leakage tester cost less than a pre made one

Well lads, you work in the real world, not presenters and if you were, you would be richer. But you are sparkies, thanks for doing the video.

Bus bar. As in 'Omnibus' providing for many things at once.

Had this. A few circuits under 1 section of CU. Could trip 4+ times in 24 hours then ok for 8 months - I kept notes, boiler was one of the circuits. At one stage, thought maybe humidity effect so disconnected outside socket. Lasted a few years. Far too expensive to pay a pro so started checking all appliances and sockets myself. Oh, wow! I've posted before about sloppy spark work. Wires loose, oven on a 20Amp mcb, so many flaws. How to find a trustworthy diligent electrician? Not easy despite prepared to pay a bit extra. Recommends clearly based on whether chap (not found a woman spark yet) is likeable 'cos customers not able to assess competence. I want a separate power circuit for outdoor and underfloor void plus new CUs to latest regs. Conduit and boxes all in place. South east London

remove all plugs from the outlet in the house remove neutral wires one by one when the rcd stops tripping you know wich fuse to investigate :) :)

Could my downstairs neighbour be tripping mine, electricians can’t seem to figure it out

FYI. For many years I thought Switched Fused Spurs were all DP. Not So !!! Crazy I know, but some of them are single pole and last time I looked, (some while ago now) you could still buy them. Hence earth faults are not necessarily isolated by use of the SFS.

storm Eugine? Eunice!

Wi-Fi extender? Doesn’t look big enough.

Right...so..urm yeah buzz, definitely a brum thing. I still say school buz, buz to solihull etc..

Good video, but you haven’t really gone about the fault finding process in the correct way. Even though the Earth leakage jumped up when you switched the shower on, doesn’t necessary mean it’s the shower at fault, as it’s connected to a common neutral bar, and the fault could have been on any one of those circuits. Really you need to do a L/N-E on every circuit individually. I personally like to leave everything plugged in and switched on to start with and if the circuit shows a fault I will then unplug everything to see if it clears the fault. If it does then you know it’s equipment at fault, if it doesn’t then you can start splitting up the circuit and re testing to narrow down and trace it.

Live to earth and neutral to earth you can test at 500v regardless of anything plugged in. It won't damage anything. Live to neutral it might cause damage but I've never had it happen. Live to neutral doesn't really matter anyway when you're tracing an rcd trip.

This is interesting. In North American jurisdictions where we put a separate circuit in for practically everything, fault finding like this is usually a lot easier. The "_____" breaker keeps tripping makes tracking down something faulty far faster. Very cool to see the comparison.

Got called out to a job saying I was the 4th electrician in 6 months for an intermittent RCD tripping. Customer says you've spent 10 minutes asking questions why not see what's wrong. 20 minutes later fault found. Partial leak on oven and iron individually no RCD tripping together instant trip. Question When does it trip and what are you doing at the time and what's on Answer Well I do a lot of baking so I do my ironing so I can keep an eye on it. So I just have to run them on their own then. ? Nope get yourself a new iron and get the oven checked. Look out for surge protection 4 way extension leads

Operating devices in the Shower... I think I might have this one figured out

Nice silvergrey m3 outside

IR test should have all cpc's of install connected ..... Hate rcd faults 🤣 good luck its needle in haystack rcbo boards are the future

In my local accent 'Bus' is often pronounced 'Buzz', so you can call it a buzzbar you're just saying it in a specific variant of the northern accent. Also, is it bad if an RCD trips at a lower than rated current, and why is it if it is?

I had exactly the same toaster causing rcd to trip cause hot cross buns a raisin was shorting the element to the case

Counterintuitive to say… but have RCD’s made things worse? Obviously more safe but nuisance tripping is also unsafe. There will be a time when we look back at RCD boards and think… what the hell was all that all about and why didn’t a boffin come up with a safe solution, sooner. Always a good watch, lads.

What is a ramp test

It's a busbar yes, short for omnibus bar, meaning 'all of everything'. No idea where the buzzbar pronunciation came from, but yeah, if it buzzes, you already found the fault ;)

RCDs are meant to be tested in isolation. Turning off the MCBs and removing the outgoing neutral will achieve this. I have had plenty of the older RCDs fail a ramp test due to connected loads. Once you remove them, the RCD tests fine.

Right... so.

You are so much better than that weazley looking fella on CJR

That's a small house wow.....

unplug every appliance for sure, then eliminate lights first , all bulbs out because a bad bulb will trip, then socket appliances one by one, then shower then boiler then immersion if applicable, if any has a fault you have culprit by tripping , if not must be overloading or faulty circuit.

Fault finding for RCDs Live and Neutral together test to earth as you are looking for earth leakage. Again RCD test on just the RCD with everything else disconnect. That will give you the true RCD reading without any circuits interfering. Think their immersion heaters are upsidedown E7 should be the bottom element and top element should be the top up / boost (heat rises)......

I've been sent to these on call outs. Why they don't sent you guys instead of bothering me I don't know. I'm just the gas man.

Deberían agregar subtitulo en español

Hay

Right, so...