Insulation resistance and RCDs
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- Опубліковано 5 сер 2024
- Tracing the troublesome tripping of an RCD!
A closer look at how poor insulation resistance on final circuits affects an RCD, and how detecting poor insulation resistance can point you to the problem. My thanks to Artisan Electrics for letting me link to his channel in this one. Go and subscribe there NOW dammit! - Наука та технологія
Best electrician channel, no doubt.
Thanks for watching again and for the kind comment!
Great Vid. Top tip for nuisance trips on kitchen rings with good or high IR, fridge freezers with faulty defrost elements can be a bugger as defrost cycles only happen every number of hours, so nuisance trips are number of hours apart in time, and you cannot detect the low IR at the plug as the element is separated by the pcb relays, so you can mistake the appliance as being ok when PA tested. Can be a bastard if you didn't know this lol.
A very good point, some appliances test out just fine, but it's only when a component part of them clicks in that trouble occurs. Damn, I wish I'd said that as part of this video!
Great Video again. As an apprentice I find these videos a helpful clarification of the theory we learn within a real world situation. Nice one!
How have i never seen this channel before . A gold mine of info
One of the few consumers of special brew that has a job, the olive gave it away.
Try reading the bloody regs book sober....
Excellent video - very clear example of procedural fault finding and highlighting the importance of recording EVERYTHING for clarity and for purposes of elimination. Good explanation of WHY it is done this way as well. You might act the buffoon but you are in fact a very clever chap.
There's no acting here, the buffoonery is real.
@@dsesuk that's probably the cumulative effect of the Special Brew😊
@@dsesuk I was just about to say that. 🤪
@@dsesuk it's UA-cam, so the bafoonery helps. It's a nice entertaining touch
Very sophisticated Dave drinking special brew from a cocktail glass! Interesting video, great to see a real life application of those resistance calculations they show you at college. Thanks for sharing your wealth of knowledge with others.
Dave , I am an electrician and have been for some time. I just want to say that you have opened my eyes as to due care and attention . I mean to say that there is always more someone can do so thank you!
Thank you for the feedback Justin!
Very well done. Great use of applied mathematics to narrow down the search. I hate dealing with RCD tripping on crappy split load boards, always happy when the unplugging of all the appliances remedies the fault.
I know what you mean. If you can narrow it down to an appliance then it's a lot easier than trying to trace it on the wiring!
Thank you David for an excellent video. You are like my tutor back in the day was doing my City and Guild course!
I'd have handed out detentions for any student who presented me with an apple rather than a lager!
Good tip that you must disconnect the Neutral to isolate and potential earth faults on the other neutrals. Thanks for great video
An absolutely brilliant diagnosis sir.well done.
Really interesting to see you working through the problem !!
One of your best. Real world problem solving, I actually enjoy the challenge of these type of call outs. Client is never impressed but we know better :)
Thanks, I too like a good nuisance trip. Proper detective work!
I only have a passing interest in domestic electrics (I'm a highway engineer) but having watched most of your back catalogue I've learned tonnes, as well as finding your overall style and production quite entertaining. Thank you very much indeed.
Thanks Thomas. I don't suppose you can do something about that pothole at the end of my road? My damn Greggs latte spills every time I drive over it!
@@dsesuk this guy got results www.boredpanda.com/wanksy-penis-pothole-graffiti-manchester-england/?
Granville... feh feh fetch yer cloth...
I love your channel dave. I'm more a practical guy and not the best with formulae and your videos help me with dark areas in my fried brain. You have an excellent way of educating your skills, special brew which in itself deserves respect 🤝
As an apprentice these vidoes are digital gold, keep em coming mate
Thank you!
Knowledge is power , a great example of how logic and learning ultimately provide great job satisfaction. No better feeling.
Who ever thought maths would work out useful??!
Great video David. A really practical example of basic physics. I had exactly this problem in one my rental properties: tenant turns kettle on, RCD trips, cause was another circuit on the RCD, the kettle just provided the last few mA to trip the RCD.
I have come across the kettle causing the nuisance tripping before in motel units. The kettle in one unit was not turned on but every time the compressor of the fridge in the next door unit turned on leakage through the neutral inside the kettle through the water in the kettle to earth tripped the RCD. The start up current draw of the fridge and the fault resulted in part of the return current from taking the alternate path back through the kettle earth to the neutral earth link in the switch board on its way back to the power station. Was a bit of a bugger to find especially when the switchboard circuits were just labelled power and lights with no allusion to which units they were associated.
Thanks Tony, that kind of situation can well be the case, and it can point you in the wrong direction when faultfinding!
Great video, thanks. Makes me pleased that I specified individual rcbo's on each circuit when we replaced our consumer unit. I've never seen anyone drinking Special Brew from a martini glass before. I have to say that this brings a very welcome touch of class to the video. 😉
One does try to raise the standards.
Great content as always buddy, as a spark not on the tools daily, these videos help to keep my mind in the game.
The booze helps to take my mind off it...
Just a great video, most electricians just don't get this kind of theory.
I watched till the defeat video !
However I need a lie down now !
Great video and explanation Dave. I always find nuisance tripping to be water ingress or faulty appliances. The amount of electronics in electrical appliances these days with capacitors and filters across the supply is increasing, this adds to earth leakage currents and has a cumulative effect. The best option as you say is RCBO on each circuit but hey.. Convince the unconvincable lol. Special brew is the only answer 😋
Yeah, I always hunt the water using appliances first, or those exposed to moisture such as freezers, outside electrics and such. This client has indicated he may want some or all of the circuits split off, but we'll see if he ever books the job in.
Excellent video, very well presented - informative and humorous
Cheers Andrew
My favourite cocktail, special brew-tini. Great video mate.
Stirred, not shaken.
Easily the best electrical discussions on the internet are by Dave, he even makes them funny !!! Yes u r funny Dave 😜 Keep up the interesting posts and thanks 👍
Thanks Mike, I shall try!
Informative and funny in equal measure...bravo!
Brilliant video, great explanation on what you're doing as well. 👍
Cheers Richard!
Your presentation style gets better and better. I spunked my coins on RCBOs for my CU and I always buy the most expensive tyres. There are some things in life you should never compromise on - certainly anything that involves safety and you use every day. Like your CU, tyres, toilet roll and beer.
Amen to that, although I would have prioritised them in the reverse order...
Great vid. Totally agree about customers view of what's causing a trip. Totally agree about customers and consumer units. The way I put it is, no one has their friends round to show them their new consumer unit. But I long since abandoned split boards. RCBOs only for yours truly. Love the maths (Not -I'm a history graduate ffs!), but in my simple mind I've have gone straight to the kitchen socket circuit, without all the science.
Your videos are gold
Great Video Dave, keep them coming 👍
Great video and a very constructive maths lesson!
Great video getting the brain ticking on a Sunday evening.
Liked the cocktail too🍺🍺🍺🍺🍺
Special Brew sure puts the 'cock' into cocktail!
Ha, ha... my fave video yet. Great information. Love your dry sense of humour. We'd have a hoot, me and you. I'm just as satirical/ ironic/ sarcastic... though not quite so 'mucky mouthed'.
Another excellent and informative video.
Well a tad embarrassed..I subscribe to your channel and yet have hardly looked at your talent! The above video is going to help me no end,( got a cheeky rcd fault to get me noggin around) and to that end I shall endeavour to watch all your videos coz there just groovy..Thank you lots and lots and lots.
If you can find any talent here then you're doing well!
Special Brew out of a martini glass... Very sophisticated 😂😂😂
Not only that but an everlasting glass of beer.
That olive was a nice touch. Little umbrella next time please. 😁
How do _you_ drink your Hobo's Choice?
Hi David I really enjoy your technical knowledge I thought I was clever until I saw you
Really happy to see another good spark out there but seems to be a dying breed
I could watch your videos all day and nice to see someone call a spade a spade
Great video, will be watching a couple more times to sink in 👌
That's the trouble with maths, the BASTARD never lets you just get it the first time. I never did get the hang of it myself.
Hi Dave, thanks for great videos. The draft on brew is not so special, guess that is why it trips rarely. Cheers
Brilliant vid that. Keep em coming kind sir!
Thanks Andrew, I shall try!
I will watch this video over again a few times
Nicely done Mr Savery!
Thank you very much sir!
This video remind me on my most horrible RCD foult. We installed a addional outside socket. In the main board there were 2 RCD 100mA for the heat pump and a 300mA for the rest of the house. So I told the customer we have to change the RCCB with a 30mA typ. This was no problem. RCD was quickly changed, tasts were carried out and the job was finished. Untill the customers called and told me the RCCB tripped over night. So I went there and don't find any problems. After 5 times visiting the customer and 14 hours. I found the failure. There war an old time controlled heating circuit in witch N come from the lighting circuit and the L of one relay was connected to the heat pump RCD. When the timer was off there was no fault.
Ouch! The ol' borrowed neutral strikes again!
Brilliant video David, both funny and informative. I do think ring final circuits should be on their own RCBO's as there's a greater chance of an earth leakage fault occurring due to the shear numbers of electrical equipment that can be plugged in and faults introduced onto a circuit.
Thanks Alvin, most earth leakage faults tend to be on appliances connected to the socket circuits from my experience, so if they can be segregated then it's better for them and their sister circuits which may otherwise be pulled down. RCBO's are the way forward, but we all know that. Convincing a customer that it's their best way forward is the hard part!
@@dsesuk More often than not, always an appliance with a heating element, kitchen is always a good place to start.
Great video, will be watching again , I want to get back into domestic it can be challenging
Love this guys sense of humour but not his taste in beer :)
Quality Vid. Great tips.
Nice video D. The problem with dead testing (IR) where appliances are connected is that the appliance may only present the fault during its working cycle. I see PAT testing as superficial, though it does make sure that Class I equipment is earthed, correctly fused and no visible damage to electrical cords etc. it gives no guarantee of appliance being OK whilst going through it's various segments of operation.
This is very true. Testing something like a washing machine is all well and good, but what number it's giving when full of water with the motor and heating element kicking in is something else entirely!
ahhh yes sounds like it was one of them jobs, even harder to find on a split load board on the RCD side !, I can imagine the frustration when you rocked up on site lol.
This one wasn't too bad. Two hours on Friday morning was all, but it was a bit whiffy around that septic tank, hence our relief when we were able to track it down elsewhere.
Maximum respect for the use of IT and I love the dses sign . What is that, your office ? Or a workshop of some sort ? Never noticed that Appendix 5 does it really say special brew?!?! I'm inspired to look now. I always have low NE IR for old fluro circuits. Which is in fact all of them as most new ones are LED now. I wish I knew what this was about and why nobody else seems to mention the problem. I know about LN with the capacitor and electronics, but consistently in various sites over the years I get low NE too. I'm almost at the point of well in fact I am, total surprise if this doesn't happen now. As you say, it is a right pain to diagnose without disconnecting all the lights. Got it with SONs last week too, disconnected them all and it was all 9's again. Neutral to Earth. On another point, when I saw your goodie bags from ELEX after depositing that last Xcite flood and getting my bacon buttie at CEF on Friday, picked up one of them codebreaker books you had just what I've been looking for all these years but then after reading it found it still leaves a lot to the imagination. Particularly with the issue of commercial installs without additional protection, still in a quandary of what the official position is. Guess I'll go with billions of risk assessments or just disconnecting those ccts I deem dangerous without it - for instance in a shower unit with a broken cover which comes off if you touch it exposing the terminals for cleaning! No additional protection either. Mmmm.
Cheers Rupert, it's a formerly dark corner of my garage! The sign used to be on the side of my van! I don't come across too much trouble with fluorescents, but then most of the places I'm testing are domestic, so they don't have many. Couldn't say why a fluorescent would have leakage to earth - I wonder if there's a difference between the old magnetic ballasts and the electronic ones? I haven't looked at the Codebreaker book much yet, but it's my kind of bedtime reading. I don't suppose it has all the answers, but it'll be interesting to see what insights it offers.
Used to look after the cooling equipment on a dairy farm where they had a bypass switch for the RCD as it wouldn't stay on in wet weather.
Oh my, that's rather priceless!
Excellent video Dave
Thanks Gerard.
When doing IR tests it is purely resistive (DC), but as is happening more now is the fitting of EMI/RF filters in modern equipment, so parallel reactive (capacitive) loads, so now I'm thinking maybe we need High range ESR test gear as well. Years ago when doing hospital maintenance and installs, we often had to install 100mA and 300mA RCD's (which sounds high) cos with the capacitive leakage (from the built-in EMI filters) on permanently connected medical equipment) it only needed between 10mA-20mA to earth to trip them!
I got called out one rainy easter sunday by a local farm manager. Reason tripping RCDs. So disconnected circuits at the swb. Found a rat chewed cable where the septic tank circuit exited the building inside a marley end box. Fixed that one circuit down. Found next one was a Rat chewed cable directly above the switchboard in the roof space where the rats had chewed a good 300mm of the outer sheath and the primary neutral insulation away. A quick look around in the roof resulted in many other similar rat dinners. Fixed all that I could find and advised client they had a rat problem and was most likely due to the half meter deep mound of recycling waste they had piled up in the garage. Farm manager said they normally save it up then take it into town. Farm manager started clearing waste into his trailer exposing large holes in the plasterboard wall behind the wates mound. Inside the wall were two 25mm single core conduit wire tails on the incoming mains conductor, they should have been installed in conduit but this was obviously too hard for the original installer. These tails went up the wall into the exterior tariff meter box. There was no insulation on sections of both of these tails leaving 100mm sections totally exposed on the neutral and some smaller chunks out of the active conductor insulation. Another rat supper. Had to get the line mechanic out to pull the pole fuse to allow me to repair the insulation on the tails and install it in conduit up the inside of the wall. Almost 8 hours spent on call out rate due to some one not wanting to process their recycling regularly. Sent one of the residential sparks back the next week to disconnect all switches and sockets etc. in order to pull cables up the walls into the roof space to check if any repairs were needed due to rats getting into the walls elsewhere. I should add that this was a wood framed house with exterior brick, so all walls had cavities.
Crikey, I don't think I'm gonna sleep tonight after reading that! One of those jobs I hope I never get called out to!
@@dsesuk They were very lucky that rats only seem to like the primary insulation on the neutrals and not the actives. Have had similar on other jobs in the past and the RCDs only seem to trip when the rats pee on the exposed wires. It was actually a nice little earner for a rainy Easter Sunday. Great videos by the way, very informative and entertaining even if you are a POHM.
Another super vlog 👍 And looking very posh with best shirt on, hair brushed and posh drink 😂👍
It's Sunday, so the McHat gets a day off and the expensive alcohol comes out!
ok i have a daft question if i wanted to make a mobile protected power board much like the main house power box what devices would give me the most all-round protection given that im renting and would like to protect myself from any eventuality.
I usually find RCD trips are faulty kettles washing machines etc. If I'm doing a board change on an older property as a minimum it's good practice to fit a high integrity board so you have that RCBO option. Not all customers have the money to chuck at all RCBO boards.
I always go for the appliances that directly use water first, or those exposed to moisture such as fridges, freezers, exterior lights and sockets, etc. I also check if it's raining when the report of a trip comes in. Single pole RCBO options have really dropped in price though (double-pole remains pricey, but the best option).
Had cafe I wired up complain as new toaster was tripping. Turned out to be a raisin stuck in toaster. Ha .
@@glynowen1349 I've had exactly that before with my own toaster!
@@glynowen1349 I bet that was the easiest £30 you've ever made! Unless you're like me; happy to be paid with a Full English...?
I had an issue of tripping with solar pv. it would occur daily around 1pm (around peak solar).
Good work
At an existing installation I would have preceded to do 250V first to make sure you don't blow up the kids Xbox on Christmas.
As line and neutral have been joined, the potential difference across them should be zero, but we often test first at 250V if we're not sure what's on the circuit.
@@dsesuk Just wanna say I stumbled on your video and I first thought this guys a complete joker... Turns out you are, in a good way. Your knowledge in commendable.
Great vid Dave,you sponk on as much as you like
Good job you didn't have your special brew shaken could've been messy great vid dude.
He's planning on spending the night in a park shouting at squirrels!
Pah! Some pesky VAGRANTS were on my bench, despite my previously marking it as my territory!
@@dsesuk You can't say Tramps these days - PC gone mad!
Drinking special brew from a champagne glass with an olive....PRICELESS........Great vid also........thanks
It would be unheard of to leave out the olive. This is Leamington Spa don't you know?!
Thanks Dave
Brilliant
You are the man.
You had me checking blue book 😂
If I worked for the IET, I'd sneak it in and see if anyone noticed. Considering the mistakes in there, they obviously have lax proofreading and checking of their publications!
Hi David love your videos, nice to see some talking sense and talking the job sireasly with a bit of fun and light humour,
I would like to know what is the point of doing RCD tests at half times, one times and five times when we are only required to record the highest value?
This seems to be a waste of time and effort, just my own opinion. You have even said your self that some of the regs are stupid and controdict the self, point in question the removal of the supply cutout should we or shouldn't we? And the video you did were you did a EICR
and found no problems yet the guy who did the EICR before you condemned the installation?
Great videos and work from you please keep them coming
Hi Sean. The gamut of RCD tests have their place - we want to know that the device operates at 1x and 5x test current and that it isn't too sensitive that it will trip at half times. As for recording the result, I agree that it's a nonsense now that the 1x and 5x columns have disappeared from the Schedule of Test Results as you've no idea which test the figure relates to when looking at someone else's form.
@@dsesuk thank you David, and please keep the videos coming, I did C&G 236 part's one and two back in the late 80s but I have worked since 2006 due to eal health I know a lot has changed but I do try to keep up with the regs and so on once again thank you. Oh and next time you decide to cut your hair try using a colinder you might end up with spiky hair LOL
The Joy to come home on a Monday after seeing some terrible wiring and a extraction duct full of water in a bathroom to Have Dave drink out a martini glass🍸excellent in my best Montgomery voice😁
If it brings you joy Derek, I'll pour one in your name every night!
David Savery Electrical Services 👍🍸🍸😁
Hi David say a single circuit on a rcbo how low would the insulation resistance reading have to be to trip the rcbo
Good video, thanks. Is there not a risk of damage to equipment when meggering, especially at above 250v? But if you DO disconnect the appliances, how do you then identify the faulty unit? Be interested to hear your thoughts. Cheers.
To minimise the risk of damage to equipment if you can't (or haven't) disconnected all loads, you can run the test at 250v or, as we've done here, join line to neutral so that there is no potential difference between them. What we're doing here is essentially the same as one of the tests a PAT tester would do. There is always a risk you could damage something, but appliances should roll out of the factory capable of surviving a basic PAT test.
Phew ! Think I need a special Brew after that. Can’t stand Maths myself, but very well put over. The Solar Pv circuit should never be installed on a shared RCD By the way. In the event of Joe Bloggs getting electrocuted and the RCD doing its job and tripping, the inverter can take up to 5 seconds to disconnect, therefor injecting electricity onto the shared bus bar and Mr Bloggs.
Like many PV installations, I took a few issues with that one. For a start, there was no DC isolator at the inverter. That was the problem with the MCS bullshit though, it was all geared up for the slap-it-in big-boys, while small-fry such as myself who actually cared about fitting it properly for the client just got swamped with paperwork requirements, and eventually flushed out. I was MCS accredited for four months back in 2014, and that was as much as I could stick.
I had the same issue. Completely random Rcd tripping. Once a week. Maybe once a month. I changed my diss board to a 12way rcbos and since no issues. I have a 20ma leakage to earth but just can’t track it down. I guess the best thing to do is to clamp each earth to see where the fault is coming from.
great video as always and i have nothing to say for once lol
ok that’s just weird the special brew in a martini glass is weird but throwing a olive in there as well wtf 😂😂😂 Your a mad head. but that aside excellent explanation excellent video man
I feel their pain, our dishwasher was cause of constant RCD trips just this past Xmas, the heating element developed a tiny pin hole.
Often wondered though, the RCD's are about 2 slots in size, why are the RCBO's the same width, with only little additional height as a breaker, when they do the job of RCD and breaker, what about failures of such devices...
I suspect the RCD form factor is largely a legacy one. It also may be rated at 80-100A unlike individual circuit RCBO's which tend to be rated lower. The older style tall RCBO's probably contained about the same amount of space, but they're shrinking them right down now, and the new models are little larger than a traditional MCB. There's also supposed to be a three-in-one device coming out with arc fault, earth leakage and overcurrent protection built in but in the same size housing as a small RCBO.
Ahh yes, makes sense if large ones are rated much higher, thanks David, keep up the great work
..and this is why a good electrician should be paid more...!
When you done the IR test on the washing machine(I think)at the plug,it was showing 500v setting,surely you would do this on 250v first,or am I wrong ??
Unless there's surge protection in the appliance, I test at 500V. With line and neutral connected, there's no potential difference between them to fry any electronics.
David... how the f##k can you drink special brew. What's your thoughts about the 2 lengths of 6mm sq that were put up the cavity in case an electric 8/ 10 is shower was needed at a later date ? I have been told that even though these 2 cables are in 1 mcb there should 1 cable approx 10mm sq . Love to hear your thoughts. Regards Don.
We had an ring main RCD at work that had been nuisance tripping for years, sometimes ever 5 mins, had been looked at by our official sparky many times but never presented the fault :( I did the usual procedure of unplugging everything ( no trip ) then plugging in one item at a time to see if one was the culprit. Anything plugged in would cause the fault :( Eventually while I was asking our sparky to look at it again he looked at it and it tripped, prior tests were insulation and does it trip at 30ma, this time he ramped up the current from zero to find that it would trip at 12ma !
Some RCD's can be too sensitive, I have come across such before which is why the ramp test when no other loads are present is such a useful test.
The electrician sounds incompetent, that fault should have been picked up on the first visit.
@@ashmanelectricalservices4318 I suspect that the RCD had an intermittent fault as sometimes it would go for a week without tripping, yet another day it would trip every 5 or 10 mins with the same things plugged into the ring.This time the fault was present when he tested it.
@@steverpcb It was an over sensitive RCD, that fault would have been there at the first visit, did he try doing an RCD ramp test on his first visit?
@@ashmanelectricalservices4318 I presume so as the one on the ring the other side of the factory failed test even though it had not been giving problems.
The Keith Floyd of sparky world 😎🍻🍻
Showing your age there, but a fine compliment! Cheers! *hic
Can I ask how much it costs to do IR testing?
Very well explained. Was it your least favourite child filming again? Keep up the good work, very entertaining again....
No. I fired her ass and wrote her a bad reference.
Fuck me!............You know how to enjoy yourself on Christmas eve David 😀
Just as I was lining up the Die Hard DVD too. Part of the Christmas tradition, just like National Lampoons Christmas Vacation, eating sprouts, overdoing the Bailey's and being sick on the cat.
Hi David, just been watching another sparky with client who was having an RCD tripping issue, I'm not a qualified Sparky but been an electronics engineer (now retired) for most of my life, he was going all over the place and ended up not really solving things but the fault just stopped so left telling the client that it was more than likely her washing machine? I never once heard him mention a possible rogue RCD what's your take on things, as a non Electrician if that happened in my home my first call would be the RCD, I do still have the necessary test equip. so would have 'hammered' the RCD first with under,ramp and over tests just to see how it behaved?
I always start with IR Keith - test line/neutral to earth on all the circuits downstream of the RCD before removing any appliances and see what reports back as bad (presumably something isn't tip-top and one or more circuits are low unless the fault has cleared). I'd then investigate that circuit, and see if the IR rises with appliances removed. We can usually narrow it down to an appliance that way. We'd also measure earth leakage before we start and see which circuits are adding to it, and as you say, the RCD itself can be tested to ensure correct operation.
Funny thing is he's just got an earth clamp but said on the vid. that he wasn't too 'up' with it and it's not found any faults for him yet? I mentioned RCD because I personally had a rogue one a few years ago and it really got me going, it would 'repair' itself for weeks at a time and then just throw it's toys out of the pram for maybe one or two episodes? I tested everything but premature ejaculation (did loads of tests for that) so I suppose it's made me really distrust the bastards, also I learned NEVER to presume anything from my early years, that's fatal
I always like to hear it from an expert so thanks for your time David and advice and keep the vids. flowing, your own TV series next, who knows?
@@keithcoltron3171 Haha! I haven't got the pretty haircut needed for TV Keith!
There's a man who can't hold his liquor.
Great video, well done, but just realised that my book is a fake as i have no special brew in appendix 5, mine reads Guinness.!!!
I believe the IET issued a corrigendum switching it from strong lager to stout.
Do have you heard back from the customer on how things are going?
No further problems so long as the dishwasher is unplugged. And they've paid the invoice.
Greg Davies' twin😉
Hi,just wondering do you not have to make sure everything is unplugged before you do the test ?cheers
If you only want to test the wiring itself or if you want to test for leaks between line and neutral, then unplug the appliances. If the RCD is tripping in normal operation, then test between line conductors and earth with the appliances still attached in order to determine which circuit is at fault, and then what appliances on that circuit are dragging it down. With the appliances connected, you're effectively performing a partial PAT test on them all at once which makes for easier faultfinding than going around checking everything individually.
@@dsesuk That's great,thanks very much
@@dsesuk Sorry just one more question.If you set the tester at 500v would this not damage the appliances?cheers
Not if line and neutral are tied together as there would be no potential difference between them. Well, not unless there's a single pole switch, blown fuse or wire break on the appliance, but again, it's the same as if you were PAT testing it.
@@dsesuk Cheers for the explanation👍
Have you tried Skol Super, a lot less bitter the SB. That said, Polish strong lagers are in a different league entirely.
No, I was swayed by the description on the Special Brew can which reads "A full bodied, fruity pilsner beer with good clean bitterness and cognac flavours." I guess that's what makes it the vagrant's choice!
Don't let these tramps fool you! They may have plenty of hands on experience. But I don't think they've got the relevant qualifications, to assess the market with a degree of accuracy. I'd bench test some Polish strong lagers and savour the unique properties of Eastern European rocket fuel.
Hence my CU is full of RCBOs...
a qick tip or a quick tipple lol
Did you run out of babysham ?
You know when you've run out of booze, and all that's left is what's in the dusty cupboard of Christmas past? It's either this, the sloe gin or a dodgy bottle of authentic Mexican tequila which tastes like leaded petrol and was brought back from holiday by a friend we don't really like. And I've already downed the tequila.
Im confused. I'm being taught that when testing IR all loads should be disconnected, certainly sensitive equipment, even when testing between lives and earth. But videos from practicing sparks don't do this.
If you want to know the state of the fixed wiring, then disconnect all loads. If you want a picture of the insulation resistance the RCD is seeing in normal operation, perhaps because the damn thing is tripping, then leave the loads connected. The IR test shouldn't cause damage, especially at 250V, so long as you apply the test voltage to line and neutral at the same time because then the potential difference across them is zero. The same test would be applied to any appliance that is being PAT tested, and there's unlikely to be anything in a domestic environment that can't withstand a PAT test procedure, so you *should* be safe testing in the same way at the consumer unit. Remember, we're not IR testing between line and neutral here, doing that could damage sensitive equipment; we're testing line/neutral connected together with respect to earth.
@@dsesuk Thank you for taking the time to reply, and thanks for your continued content. Great work.
Special brew lol
I was quoted £220 for that clamp. What did you pay?
£220 is a good price, I've seen it as high as £475. This one has been loaned to me by my TIS rep after I got chatting to him in a branch of SRM. All I've used it for so far is earth leakage, I haven't played with the PQA function that the clamp/tester also supports, but I plan to for this channel as soon as is practicable!
shandy shaken not stirred lol