Insulation Resistance testing blarney

[@marcmann9038]

Amazing how a bit of humour gets the otherwise boring information to stick to the sides , should be part of all apprenticeship curriculum

[@stevenwalker3164]

A can of special brew is recommended while testing 😂

[@hootche1]

All good electricians know that a Can of special brew will NULIFIE the power supply, as it does with the HUMAN BRAIN.

[@markyd2633]

I CANNOT for the life of me believe you didn't touch that special brew once..........Another good one ...Thanks

[@dsesuk]

Cheers Marky. I'm tucking into one now just for you!

[@peterfitzpatrick7032]

Its already empty... 🙄😂

[@salamibdali9121]

love your videos mark so fuckin funny. 😂

[@davemorgan7695]

Salam Ibdali Dave’s are funny too ;)

[@FrontSideBus]

You’d be better off drinking petrol...

[@artisanelectrics]

Love a bit of Testing Talk!

[@dsesuk]

PHWOAR!!

[@richardburgess6040]

A really well produced, informative and factual video. Long may you continue to educate, inform and make us all splurt our drinks over our screens with your unique humour. 👏👏👏

[@dsesuk]

Very kind of you to say so, thanks Richard

[@Davidhamnett]

Yep, was drinking my coffee watching your video and minding my own bussiness.. then all of a sudden the fat end of fuck all came along and that was it, horizontal coffee flying through the air

[@JPElectric]

Liked that. It can be a tricky test, but once understood, essential when fault finding, and as you say covers your back on new installs.

[@dsesuk]

Covers your back, sac, crack and ass if you do all the tests!

[@trollobite1629]

*"...just ballet dances off the fucking tongue..."* That fucking killed me whilst staring very glumly at my first EICR form the instructor thrust on my desk with a smug smirk on his face 😐

[@davidroche6973]

Great video. That's for explaining the linked IR testing, I've done it on the test rigs at college but was trying my best to get my tiny little marble sized brain around how linking line and neutral doesn't cause Winny to flash...I mean light up 👍

[@pinchermartyn3959]

Really useful. Many thanks. More like this please on other testing detecting. Excellent channel.

[@robcamm7584]

Absolutely superb Dave, real world examples too. Top man

[@dsesuk]

Thanks Rob.

[@gkuk]

Hi David, love the videos and your sense of humor. Haven't got a clue what your talking about but still watch 🤣⚡🤗

[@dsesuk]

Haha! Most of the time my mouth just moves and I haven't got a clue what I'm saying either!

[@neilcrawford8303]

@@dsesuk If that's how you operate sir, then you should have a career in politics. Every politician going has continuity fault between their mouth and their brain.

[@jamietti]

What I find a bit odd is why the USB sockets are not required to have a separate switch or be tolerant to 500 vdc of normal test procedure. Do they have a fuse other than a small fusible resistor on the cirquit board? What might the logic be behind allowing them being installed at all?

[@supersparks9466]

I get a spring on watching your videos

[@pw6180]

Great Video!!! When trying Live + Neutral to earth while leaving the cooker switch left on I did get •28 MO. Is there any reason the cooker switch alone didn't take to this?

[@dave3159]

Excellent Video, good part on PAT Testing too , Thanks .

[@davemorgan7695]

Brilliant Video Dave thank you, so much useful information, most likely one day Line to Neutral testing (EICR)will be thing of the past. Great your supporting Nick and James their top guys producing good content, Thumbs up.

[@dsesuk]

Yeah, they're good lads, thanks Dave!

[@davekinsella2435]

Great info thanks. Am finding you’re vids extremely useful going for my 2391. Very informative and light hearted makes things stick in the brain with a good reference point. As much as you have now distorted my childhood learnings of Winnie the Pooh, and I can no longer see the innocence of the relationship he has with Eeyore, I very much doubt I will fail on any reference to IR testing and sensitive equipment. So thank you I think for that but definitely for openly passing on you’re wisdom, and inspiring the keen to learn, please keep it up. Electrical safety inspector Military base Long way from home Somewhere in Iraq

[@dsesuk]

Cheers Dave, and good luck with the 2391! Also, try not to get blown up or shot or anything!

[@adamsharp201]

Electrical safety inspector who is studying for the 2391 exam haha. Delusional

[@FB-gg9zo]

Just brilliant. Incredibly informative, entertaining, and just what I was looking for a week ago. (God bless the all seeing algorithms!) Thank you so much. Subscribed.

[@deanbirch2278]

Hi Coming from the automotive side of things. Do you factor in the Ohmic value of your test leads for testing as very low values are encountered. Thanks

[@dsesuk]

Hi Dean. I neglected to mention it in the video, but yes, the test leads are nulled before testing. I meant to show that, or to mention it, but forgot to do so.

[@noblackthunder]

mhh i mainly did insulation testing on motors and heating elements and some other stuff :P well cables too .. but those cables soaked up water over time and got a bad insulation resistance. Fun fact .,. have an old cable over long time under water like a silicon cable and so on can soak up water and cause en earth fault too

[@alunroberts1439]

Looking at the sockets with USB charger port why don't they make them so the socket switch turns it off for testing also save on all stand by power just think 5 million of them. Saying that any switched socket I test with it on. As I had some in kitchen with grease in that ended up burning it did not show on test with switch in off position.

[@Webbster77]

Really like you doing the maths for circuit length on your sockets - such a DOH moment on a new install if you open an existing THEN discover youve made it to big!

[@asp217]

Good video. What can can low values such as 0.01 Mohms when doing a combined L&N - Earth IR test? I have heard that surge protected extension leads can cause this. I tested a domestic dwelling this week and thought everything was disconnected but got 0.01Mohms. Thanks

[@tonyhewett3729]

Loved your video, very informative and funny. It took me a while but I eventually clocked the can of special brew above your resistance box!

[@PaulphotoeyeVideo]

It's only a matter of time before the tweed suited boffins make you do the calc for circuit length and write it down for prosperity. On another note. I can't find anything about how they test znd inspect in the US. Do they I ask. Your thoughts.

[@dsesuk]

You may be right, each edition and amendment to the wiring regs only seems to increase the paperwork burden for those of us trying to do a diligent and proper job while nothing is done to stamp out the cowboys and cash-in-hand chancers. I've no experience of US testing, but someone did comment recently that insulation resistance wasn't a thing over there. It would be interesting to know more about international procedures!

[@hamidbazmi7948]

Hi, Ze, IR etc testing should be on the main switch or on SPD? Thanks

[@Tselectricals]

Excellent tutorial sir ❤❤❤❤

[@mikedowell8028]

Hi good video , just think with having los of apprentices coming from collage they only see IR test that pass and none that fail so think it would be better that you show IR test that fail such as anything under 1 ohm fails. On all circuits but above 1ohm passes although on a new build 2 ohms can sort of pass but is not recommended, also a low reading can be just damp , and if you leave mega on you can prove and dry out and prove that it is indeed damp that caused the low reading , also you could mention that having a reading off 500ohms say will not necessarily blow a fuse also that in quarry s you often see readings that low

[@mikethemask1525]

Any sparkies on here in fylde coast area looking to take someone on I'm currently looking?

[@anthonysykes542]

"Winnie the pervert" hahaha, I've only watched this 1 video of yours and you've already gained another sub! Can't beat a bit of humour in this trade.

[@scousepie2]

Can you do a full test function on the Megger 1552 please

[@bobbyedmondson5500]

Can only presume the special brew was already finished....... Most informative videos on here. So good to see how other people do the job ✌

[@dsesuk]

Good deduction sir, that one had been previously extinguished, otherwise this video wouldn't have happened.....

[@mcc5651]

Very nice videos, proper information, in depth and still manage to be funny. Thank you!

[@dsesuk]

Cheers!

[@radofficial4672]

Question.. I see 15v across neutral and earth, if I switch off some breakers to an extension I've just built.. it falls to 6v. Is this an earth issue "possibly inductance”, do I need to add more earth rods ?

[@g0fvt]

RAD Official My guess is that your earth is not the immediate problem, it sounds like you have excessive resistance in the other conductors. With a load on in the extension are you seeing a big drop between live and neutral?

[@radofficial4672]

@@g0fvt I switched on/off the AC and other items in the new extension, no change between live and neutral it’s stable around 228v, but I am getting that difference in voltage between neutral and earth. Is it possible a piece of equipment is causing this, or just the fact that when things are connected it’s adding to a voltage rise.. for some reason?

[@g0fvt]

RAD Official that supply voltage is a little lower than I would expect, I wonder what the voltage is at the main house supply. Normally the earth current is very low, some appliances with mains filters will pass a little earth current but very little. It might be worth extending one of the multimeter leads so you can measure the voltage between the incoming earth and the earth in the extension. There should be next to nothing between the two points. There are various different ways that the supply earth can get to a property if your “earth” is a TT type (ie a grounding stake) it would appear to have a significant problem. Personally I would investigate that prior to adding more.

[@ttff6810]

great video David, some good gags and a "proud spring on " had me in giggles, some good education in the as well cheers

[@tartrazine]

What's the insulation resistance of the Carlsberg Special Brew shown? Or is it drinking resistance?

[@dsesuk]

I have a low resistance to it, almost to the point of a short circuit.

[@tonybaker7453]

Great video. What about IR on fluorescent fittings circuits, doesn't the ballast leak to earth. Not going to disconnect every one (too many and high up). IR to switch and Limitation or what? No one seems to know.

[@dsesuk]

Thanks Tony. As we mainly deal with domestic or only small commercial, we don't tend to see problems with fluorescent ballasts, but perhaps in number they can be problematic, I don't know I'm afraid. I would say though that if there are too many and they're at height, then a limitation in their testing wouldn't be unreasonable!

[@tonybaker7453]

@@dsesuk I'm at a rugby club and their main hall and corridors have old units chucking up such issues. I am going to list as limitation and recommend that they are all changed and tested within 1-2 years. Thanks.

[@tonyp2878]

According to r1 r2 readings 2.5 line and 1.5 cpc your circuit length is 5.7m and not 5.3m

[@JamesMossR33]

Not an electrician but your videos are unmissable, great stuff!

[@dsesuk]

Thank you Mr Chops. If that is your real name... which I doubt... :)

[@JamesMossR33]

@@dsesuk Nah, it evolved from an old school nichname 'Moschops' based on my surname. Glad you asked? Thought not 😋

[@dsesuk]

@@JamesMossR33 Moschops?? Was that a TV show or something? It rings a bell...

[@liamjordan3470]

Dave what do you think of metrel testers to which i have 2 ,which has a funny story attached 🤔 they are always give me grief buttons ,any sign of cold 🥶????

[@imranmajid1978]

Please, please give up electrical work and become a stand up comedian! I simply love your scripting!

[@dsesuk]

Haha! It's alcohol powered humour Imran, electrical work drives you to drink so it's the only job I could do!

[@jaye8578]

Best & funniest sparky on utube😂🤣 And very knowledgeable too

[@davidmarsden8868]

@@jaye8578 gotta agree.. has me in stitches Similar sense of humour I guess

[@HeathenGeek]

If that can of special brew was sitting on a metal box, would it be classed as an extraneous-conductive-part?

[@dsesuk]

Yes, this is why I advise the use of beer in bottles rather than cans when working around live equipment.

[@rossmurdoch7870]

Excellent video again David. Informative and entertaining as always. Winnie the pervert may stick longer in my memory than the IR instructions but so be it, I can watch John Ward again

[@ashmanelectricalservices4318]

Brilliant video David, a lot of companies out there that claim to specialize in electrical saftey testing limit IR testing between live conductors irrespective of how many loads are on the circuit under test. I remember Sparkyninja being subcontracted to carry out an initial verification on an installation where integrated downlights and appliances had already been second fixed and switched on 😂😂😂

[@dsesuk]

Thanks for the feedback as always Alvin! I saw that vid too. It's nuts out there!

[@JBE]

Started to watch this on my phone but 2 minutes in Poldark went off and I watched the rest on the TV. Great information explained in an understandable way. I remember a few years back when I was still with the NICEIC my assessor made me remove all the USB sockets before carrying out an IR test, even then he said keep it in 250 volts just in case. Nowadays I just blast everything with a million volts and walk off FYI- I have no idea what Poldark is. Cheers for the mention Mr Savery as always nice video 👍.

[@dsesuk]

The pleasure of pointing out your lack of being able to properly nurture a Pot Noodle to full maturity is mine my friend! By the way, I have family in your neck of the woods who asked me last week if I knew an electrician. I'm afraid you're in the chair if the shit hits the fan up there!

[@noskills9577]

Good video, I always do a 250v before diving in for 500v. Almost a certainty theres a hidden socket with something in it somewhere 😂

[@dsesuk]

The ol' USB socket located in the secret sex dungeon/kidnap attic that the homeowner never tells you about.

[@noskills9577]

@@dsesuk I never get invited to those...

[@carlinglis7705]

Hi David, quick question - if there's a socket with USB charging points like the one in this video, is it good practice for me (as the homeowner) to put a note on the CU calling it out and mentioning where it is?

[@dsesuk]

It certainly wouldn't hurt, although anyone performing a competent inspection either because they intend to modify a circuit or because they're performing a periodic should work under the assumption that fixed loads are present or that there may be an item of connected equipment they've missed. Unless it's an initial verification, then cautious IR testing is called for, and in most cases I suspect L-N IR testing is omitted entirely.

[@adamsharp201]

Unless u r an electrician u shouldn't go anywhere near a fuseboard fool

[@NBundyElectrical]

🙌 cheers Dave always a pleasure to watch 👍

[@dsesuk]

Thanks Nick, i didn't miss you out this time.... Mainly because that screwdriver price gave me palpitations....

[@Mike_5]

@@dsesuk i think he got it cheap off the Tat man

[@dsesuk]

The copper recycling does pay off...

[@Mike_5]

@@dsesuk to be fair you need to be very careful about the sort of Tat man you go to i would personally avoid the one who has an endless supply of soap bars

[@NBundyElectrical]

When it arrived I got the (insert spring noise) but I do use the hell out of it so will pay for it self in a decade or so 👌

[@keithcoltron3171]

Hi David, you should be on KZbin :-) VERY informative and VERY entertaining which makes all the difference, keep on truckin', great!!!

[@dsesuk]

Not sure it's the platform for me Keith!

[@AndyK.1]

Nice refresher thanks.

[@anthonytoohey3813]

Great video man Very informative

[@neilcowen2831]

Love it mate great stuff 😂 great content

[@neilconroy2055]

Great video Dave, keep them coming!!

[@dsesuk]

Cheers Neil, I'll try!

[@garethwood439]

Thanks Dave for such an easy to understand, informative video.

[@MaxEpsom]

How would you test a ring circuit 2 lines 2 n and 2cpc !!

[@graemebell8242]

Do you have a wiring diagram for your test rig/consumer unit? I am looking to make up something similar for the apprentices to do some testing/fault finding on at the shop. And help greatly appreciated.

[@dsesuk]

There's nothing fancy here old sport, just five metres of wires looped up in that big box!

[@graemebell8242]

@@dsesuk thank you kind sir for providing me with that detailed wiring description. I shall set about measuring out 5 metres of the finest 6242y for this installation. How long is 5 metres? . I only work in 3.75 metre lengths.

[@dsesuk]

Maybe then install two x 3.75 metres... although with my shit maths, trying to figure out the resultant of that has already blown my toupee off!

[@teamsjonline]

Had a light fail when working on a DB in a dark room, up a ladder and forgotten spare batteries..nah never happended to me !

[@robkelly5722]

Educational and hilarious! My new favourite sparky channel!

[@TheChipmunk2008]

OSG.... bleargh LOL I carry the big blue BS7671 itself around, it inspires confidence in customers. I think. It's also handy for standing the tea mug on

[@dsesuk]

I know, what a load of shite. I have literally just this evening bookmarked my blue copy after already having it a year. It's the first time I've given it a basic flick-through, and the only reason I've tabbed the pages is for these videos so I can reference page numbers. Still, I need to show it on the coffee table when the NIC come a-knockin' every April.

[@TheChipmunk2008]

@@dsesuk We found you can get away with an e-copy on an ipad of the OSG ;)

[@matthewdale956]

David Savery Electrical Services also handy if no bog paper on site

[@robotanomonous7505]

Thanks Dave - Good informative video with real-life examples.

[@mundent]

Can you then test the board as a whole using the Line/neutral & earth without risk of damaging any sensitive equipment at 500v

[@dsesuk]

Hi Lee. If the neutral bar is connected to an RCD, then you may have to disconnect it to save shoving 500V into it. You could then disconnect all the line wires and common them together to perform the test. It's not ideal though as the result you'll get will be lower than the lowest individual circuit resistance because of Ohms law regarding resistances in parallel. As an example, if circuit 1 is >999MOhm, circuit 2 is 300MOhm and circuit 3 is 6MOhm, the number your tester will measure will be 5.8MOhm. It tells you something about the installation as a whole, but not the health of the individual circuits. This is shown in more detail on my video about insulation resistance and RCD's if it helps!

[@mundent]

Thanks David. If you perform the test as you describe it and your result is greater than 999 then does that then confirm that the whole installation is sound or could there still be issues on another circuit

[@dsesuk]

If you've commoned all the lines, joined them to the neutrals at the neutral bar and then tested to earth with a resultant reading off-scale on your tester, then that should indicate the installation as a whole is good and you don't need to test individual circuits. Oh, one other thing, the neutral bar would have to be disconnected (whether on an RCD or not) as neutral is connected to earth back at the intake (if PME) or at the transformer (if TNS) and would cause the test to fail if that connection remains!

[@ashmanelectricalservices4318]

Yes, you can... Carry out safe isolation on the main switch, if it's a dual RCD board, switch off the RCD's but keep the MCB's in the 'on' positon. Using a piggyback lead, connect croc clips to neutral bar 1 and line busbar 1, then connect remaining lead to earth terminal and zap... all clear, then test between neutral bar 1 and line busbar 1 and zap... all clear, then repeat all of the above on neutral bar 2 and line busbar 2.

[@matthaddock6490]

As all way another brilliant video have to say more of a Carlsberg export fan my self, cheers

[@dsesuk]

Thanks Matt!

[@albertkleyn111]

Excellent bloody excellent AnOTHER Great video. Many many thanks! Albert.

[@dsesuk]

Cheers Albert, and Happy New Year!

[@CrazySparkie63]

David, connected loads are a pain in the arse, but every time I approach the local barracks to ask for help disconnecting connected loads I'm told to " Do One", and hate having to put down LIM but unfortunately it's the way of the modern world. Bring back the 80's when all I had to do was bypass dimmer switches with a single pole switch or koblingsblokk, opps sorry I meant connecting block. (P.S. Koblingsblokk came from when in the 90's I was installing central heat recovery systems on a private estate and the destruction's were in Norwegian, koblingsblokk was their word for connecting block and it kind of stuck in my brain) lol!

[@dsesuk]

Koblingsblokk is a fantastic word! I might have to start using it!

[@CrazySparkie63]

@@dsesuk Also FYI Koblingsboks = Junction box !

[@abdessamedghettas7167]

Just a great Video, thanks

[@alanmurtagh4075]

Very informative and well demonstrated, 👌🏻

[@nickytesla1596]

Why is it necessary to have the neutral and live together, when in practice neutral and live have 230v potential between them anyway?

[@dsesuk]

Hi Nicky. Normally, L&N have 230VAC between them, however your IR tester is likely to be injecting 500VDC hence the need to join L&N in order to prevent a DC potential difference from existing between them which may damage components.

[@heffo1992]

Out of curiosity, what's in the big junction box beside the consumer unit?

[@dsesuk]

5.3 metres of wire!

[@heffo1992]

@@dsesuk what a disappointment, I thought it was going to be an electrical box of tricks 🤣

[@dsesuk]

Nah, nothing high-tech here my friend! That consumer unit was (literally) out of the bin at my local CEF, so no expense spent!

[@davidwatt865]

@@dsesuk I thought that said 5.3 metres of wine..

[@jaye8578]

IR test the reel of cable before use even new reel👍🏻👍🏻

[@ashmanelectricalservices4318]

😂😂😂 Good one

[@yangtse55]

Yet another good reason not to fit sockets with USB outlets - I even spotted one recentlywith a "handy" Bluetooth speaker in it.. Having watched far too many USB supply teardowns, I am VERY careful what I plug my devices into to charge ... I saw them being fitted in student areas in the university where I worked and I wonder what the liability would be in the event of iPhone destruction ...

[@krazylad84]

David you are a true legend! cheers mate for such a valuable info! you have got a new subscriber!

[@steveday7510]

Great Video! as always

[@robswingler]

There’s no way on a full rewire I’d send half a day going round wiring in Wago connectors everywhere so I could do an insulation resistance test on 1st fix .

[@dsesuk]

It's not just for insulation testing though, it's also so you can confirm ring continuity, or in the case of a radial, continuity to the end point. You don't have to check this shit, but you're fucked on second fix if something's wrong even if you suspect it's down to another trade having damaged your cabling. If you can't prove it was all good when you left site after first-fix, then the client's just going to assume you fucked up, and if you have to chase out newly plastered walls or pull up newly laid floors to fix it, then the expense for that may be expected to come out of your pocket. It's a risk assessment: do you skip the testing and hope it's all okay on second fix, or do you undertake the testing to cover your arse against things going to cock at second fix? I take the safer option because I've been on site where builders have damaged my cables in the past.

[@janesouth2943]

Dont understand the spring thing explain?

[@m101ist]

Potential energy. 🙄

[@HARRYSPADGE]

Hi David, thanks for the entertaining and informative videos. The grey box to the left of the consumer unit, can I ask what make it is and where they can be purchased. I need one like that for a project I have in mind. Do they come in larger sizes as well ? Thanks for any info.

[@001Neal100]

It looks like a timeguard 4 way weatherproof box like the ones you can get from tlc

[@dsesuk]

It's from Toolstation, code 67255, £19.06, 300x220mm and I think that's the biggest they do, but other suppliers may have something larger.

[@HARRYSPADGE]

@@dsesuk thank you. That one might just be big enough for what I need.

[@dsesuk]

It has 12 40mm holes, three around each side, and they come plugged with grommets.

[@rattlehead85]

Great vid as always David. Humour included!!! 😂😂👍🏻

[@dsesuk]

Ta!

[@jeremykemp3782]

Fantastic video

[@darrenrcps7219]

On my testing course they told us if you short live and neutral at the board you don't need to worry about unplugging anything????

[@dsesuk]

You can short line and neutral at the board (i.e. busbar to neutral bar with breakers in the ON position) to test the whole installation at once with respect to earth, but there are three things to note: 1. Make damn sure the installation is isolated and that the short is removed before anything goes live again (I really don't like the idea of this as it introduces the potential for a major fiery fuck-up). 2. The neutral bar would have to be disconnected, otherwise it's already connected to earth in a TN arrangement so the test would fail (again, I don't like this as some idiot may re-energise the installation after forgetting to reconnect the neutral bar making all appliances appear dead when they're actually live). 3. The resultant measurement would be lower than the lowest individual circuit measurement because of Ohms Law for resistances in parallel. This means your tester might give a reading of, say, 0.5MOhm simply because one or more of those circuits isn't optimal on its IR. That number only indicates something isn't 100%, it doesn't indicate which circuit(s) need further investigation. In short, it's a bad idea as whatever time it saves isn't worth the potential dangers being introduced, and the number you get out of it isn't particularly helpful. More on this can be found in my April video on IR and RCD's.

[@darrenrcps7219]

Yes they told us do the IR for the whole installation and then if the result is suspect you would then have to go to each circuit one by one to find your problem ....... I suppose it's the same thing as you doing live and neutral to earth for each circuit individually and not having to worry about unplugging etc if you missed something

[@dsesuk]

Personally, I wouldn't bother testing all circuits simultaneously on a periodic inspection, as it's pretty much guaranteed that one or more circuits will give a less than optimal reading, so for the effort of disconnecting the neutral bar and commoning up the lines and neutrals and the risk of making a cock-up when re-energising, you may as well just get on with testing the individual circuits anyway!

[@Marco-mg9tv]

David Savery Electrical Services Hi David great video. Your reply above wrt testing the whole installation at the board, with the main switch (DP) off, all circuit breakers/fuses on, why would you need to “disconnect the neutral bar” on a TN (S or CS) system ? There should be no path between neutral (or line) and earth on any and all final circuits ? (not withstanding there may be under fault or degradation circumstances)

[@Marco-mg9tv]

Hi David great video. Your reply above wrt testing the whole installation at the board, with the main switch (DP) off, all circuit breakers/fuses on, why would you need to “disconnect the neutral bar” on a TN (S or CS) system ? There should be no path between neutral (or line) and earth on any and all final circuits ? (not withstanding there may be under fault or degradation circumstances)

[@muzikman2008]

Another enlightening educational fun packed video Dave. I wish my lecturers at college in the 90,s had your sense of humour. I always start off at continuity, then 250V, then 500V IR test, so i'm already complying with the DSE code of practice :-) Try it on some T&E that's been installed outside, open to the elements for a few years. surprising how much the IR breaks down, which is why I always inform customers it needs containment in conduit or use a correctly IP/UV rated cable.They never believe me of course lol.

[@dsesuk]

I hate seeing T&E on the outside. It's not the sign of a professional installer in my opinion, and like you I've seen it degrade when exposed to the elements over time.

[@jaanusriiel4535]

Some light switches have their own indicator lights. Is testing possible or i have to remove switches?

[@markyd2633]

Have you done your testing course?

[@dsesuk]

There's no point IR testing anything L-N if any loads on the circuit are connected, this includes LED or neon indicators in switches. You'd have to remove and wire out the switches to get a reading for the wiring itself, and it's probably not worth the effort unless you're tracing an overload fault. You can still test L-N together with respect to earth as switches with indicators shouldn't be leaking anything to earth.

[@jaanusriiel4535]

@@dsesuk I saw answer in video too. Just managed to ask before you explained that point

[@dsesuk]

No worries chief!

[@jwflame]

That depends. If someone actually provided a neutral at the switch and the indicator is connected between L&N, it will show as a fault if testing between L&N, just like any other load does. If it's one of the old style ones wired between L & SL and only lights when the switch is off, it won't make any difference to the test. Such things are uncommon now as they only work properly with incandescent lamps. If some buffoon connected an indicator between L & E because no neutral was available, then it will show as a fault, and must be removed.

[@zu1875lu]

Hi from the thickies out here. It said 7.14 for 2.5 but you put 0.00741....can you pls explain 🙏

[@dsesuk]

Ah, sorry for the confusion! The On-Site Guide gives the resistance in milliOhms per metre, so that's 7.41mΩ (7.41 thousandths of an Ohm) as the book lists it. The calculation we're using uses Ohms, not milliOhms, so when writing it out we need to move the decimal point three places to the left: 7.41mΩ = 0.00741Ω. If we were to do the sum without moving the decimal point to correct for it being in milliOhms (i.e. just 0.04 / 7.41), we would get 0.005 as an answer as the decimal point is in the wrong place (it's out by a thousand). Another way of doing the sum would be (0.04 / 7.41) x 1000 as that would correct things without having to faff about with decimal points. I hope that makes sense!

[@zu1875lu]

@@dsesuk thx David, much appreciated!

[@deanpaterson301]

Just the information I was looking for... and laughed too.. excellent video ..

[@dsesuk]

Thanks Dean, I'm glad you found something of use in there!

[@chesharmy3873]

Great info thank you

[@MagnetechSolidSolutions]

Very informative video as usual David, is there a possibility on giving us a future video on the run down of the Fluke installation tester? Cheers, Noel.W, Magnetech Solid Solutions Ltd

[@dsesuk]

Thanks Noel. The only Fluke I've got is the 1651B which is long in the tooth now. I mainly use my Metrel MI3100s and TIS MFT Pro, both of which I've made videos about in the past.

[@gazdkw82]

Iv watched 1000's of KZbin electricians documenting their work. So when I first spotted your videos I thought to myself, oh no not another electrician doing videos. I'm kinda done with that. However im glad I persisted. You sir are the funniest electrician on KZbin, plus one of the most informative. Spat my coffee out at "fat end of fuckall" Brilliant.

[@dsesuk]

Thanks for your persistence Gareth!

[@johnavery15]

Great educational video as usual. You make me laugh out loud so much - love the humour! You have a great name too - but an 's' too many I'm afraid! Could you do a video or part of a video on under kitchen cabinet lights - what's available, how best to wire them, etc. Keep up the great work!

[@dsesuk]

Thanks David. An interesting idea. We're not on any kitchens at present, but something may pop up we can take a look at!

[@doncodman913]

Great explanation ,many thanks. Can't help think that you should have a Ade Edmonson from the young ones help you . Rgds Don.

[@dsesuk]

Thanks Don. If Nige wears his glasses instead of his contacts, then we do make quite the tribute act.

[@normanboyes4983]

Great content and humour.👍

[@OliverONeill]

What's your professional opinion on the Special Brew vs Tennent's Super debate?

[@dsesuk]

I could go either way Oliver. The Brewsters play the long game, but the Supers have a stronger offensive strike. Either way, I end up crying on the toilet.

[@muzikman2008]

@@dsesuk I had to ween myself off that shit in the late 80's pmsl...alcoholic treacle! :-) might get some for shitz n giggles though.

[@liamjordan3470]

I wish big firms put a decent price so this could be done hence I don't work for

[@ninav74]

Hi David. New to the industry so really appreciate the educational video. I'll be sure to watch all of your videos now. Can I just clarify my understanding please? So, if low IR between L&N, that means something is connected, but L/N&E should still give a high reading in that case. A low reading between L&N, but also low IR between L/N&E would indicate a fault. Is my thinking correct?

[@dsesuk]

Hi Nina, thanks for tuning in! A low reading between L&N *may* indicate a connected load; certainly that's more common than a fault condition. It's something that warrants further investigation if you want a number out of L/N. Connected loads shouldn't provide a path to earth though, at least not unless there's something providing an additional service between line/earth such as a surge protector. I'm speaking of domestic equipment of course; commercial or industrial equipment may have goodness knows what to confound things! A low reading between L/N&E, especially at 250V so SPD's aren't triggered, needs investigation. Something's causing it, and it can potentially cause trouble!

[@ninav74]

Thanks for your reply, David. Yep, it’s a domestic socket circuit. Definitely no surge protection and all accessories have been removed (as far as I can tell). L-N is reading 0.25M at 250V and L/N - E is reading 0.5M at 250V. Obviously, I didn’t test at 500V after such ominous readings!

[@dsesuk]

@@ninav74 Not great numbers those. I'd start braking down the circuit next. If it's a ring, then split it at a socket which ought to be around the mid-point and test each leg, then keep braking it down as best as possible until you find where it's bad. Of course, it may be difficult in a furnished house. We had one last year which we traced to a socket some idiot had spurred off and hidden under a floor where the neutral wire was leaking to the earthed knockout box through a split in the insulation. We only found it because they were remodelling the house; had the new carpet gone down we'd have been scuppered.

[@eddyberry8909]

@@dsesuk m

[@RWATraineeElectrician]

Thanks for the video 👍

[@dsesuk]

You're putting in the viewing hours at present Richard!

[@RWATraineeElectrician]

David Savery Electrical Services I sure am, getting balls... erm really into everything electrical, in anticipation for next year 😎

[@jamescol2766]

Great Video Dave, keep up the good work 👍🏻

[@dsesuk]

Cheers James

[@stuartmc18]

The IR test is my most hated test!

[@donnierobertson3088]

Great job again like always

[@56jmack]

learnt quite a bit there,good vid,enjoy your can

[@strongerandwiser2023]

Why do we test at 500v and not just 250v ?

[@dsesuk]

IR testing is a 'pressure test', so performing it at 500V puts the wiring system under some extra strain which, if it passes, ought to mean it will operate happily at a nominal lower voltage.

[@fennybenton8705]

Mr slavery you make fun learning mate, don’t ever stop making these videos.

[@terryselectricalservices8234]

Great vid mate , still got the old stock special brew lol

[@dsesuk]

Y'know, they were bought at Sainsbury's not too long ago. I guess they shift the stock quite slowly there!!

[@digitraxuk]

Just wanted to say bloody brilliant videos. You answered a couple of things that have bugged me for too long. Thanks so much for the CPD it is very much appreciated. It also explains why other electricians have been so much quicker when it comes to doing periodic inspections - sorry EICR?

[@dsesuk]

Thanks David, and you're right that inspections take time. If someone does it quickly, they've cut corners. Someone who does it quick and cheap hasn't really done it at all. Even if it only cost £60 instead of the legit guy who quoted £200, it's not value for money if it's not worth the A4 the results haven't been written on!

[@digitraxuk]

That’s truly good to hear. I often feel as if I’m earning nothing based on the time it takes me and hearing the contractor saying oh well the other electrician does it so much quicker than you it’s cause you’re not experienced (which might be true). I’ve never used LIM on my results as a) I work in the domestic environment and b) always felt uncomfortable leaving a property knowing I may have missed something by using the LIM. Then there’s the am I just pissing off customers because the powers off. At least I can sleep at night! But I gather the other guys do too. 😂

[@adamsharp201]

@@digitraxuk delusional