How to differentiate Line, Neutral and Earth when wire colours are indistinct? - Page 1
Forum section: electronics / general

author: HwAoRrDk
author_rank: Super Contributor
timestamp: November 11, 2024, 03:54:39 pm
content: Are there any methods using simple test equipment (e.g. just a multimeter) that can be used to differentiate which mains wires are Line, Neutral, and Earth? We're talking about UK mains wiring here.The context here is that I'm trying to advise my Father in his attempt to replace an old ceiling light fitting, but we've hit a bit of an unexpected snag. The mains wiring coming out of the ceiling is of rather indistinct colouring, such that we're not sure what wires are what! There are three conductors: two that appear black, and one that appears brown! The two black ones appear to be the L & N, as they are what are terminated to the old fitting, but the brown one is unknown. The new light fitting requires an Earth, but I have no idea if this unidentified third wire is actually Earth.This is a 1950s house, and according toWikipedia, the pre-1966 UK electrical standards specified red for Line but black for both NeutralandEarth!. But this doesn't quite match what we're seeing for the ceiling light wiring. And I gather years ago it was uncommon for Earth to have been run for lighting circuits anyway, so perhaps none of them are Earth!

author: nctnico
author_rank: Super Contributor
timestamp: November 11, 2024, 04:19:30 pm
content: Is there no way to trace the wires back to the switch / junction box?

author: themadhippy
author_rank: Super Contributor
timestamp: November 11, 2024, 04:38:42 pm
content: First id give the wires a gentle pull to see if they've stuffed the wires in the ceiling,if not test the voltage between all combinations of the wires,that should tell you the live,check in the fuse board to see if the lighting is earthed,if it is then with the circuit disconnected from the board short pairs of wires out and do a continuity test at the light,youll soon id which wire is which.If that fails make the wires safe ,power up and see what don't work

author: Siwastaja
author_rank: Super Contributor
timestamp: November 11, 2024, 04:41:53 pm
content: This is the usual recipe for disaster: the old installation very likely does not have PEat all, and whoever thinks 3 wires need to connect to 3 wires creates a very actual death trap, this is actually one of the few remaining ways to actually kill someone still in 2000's.PE especially on device side is sacred and you must be 1100% sure you are only connecting PE to it. This is also why wire coloring is sacred and it's a criminal offense to connect any other color than yellow-green to PE. Old wires must be replaced to correct color by qualified electrician. Taping to color may be acceptable.Three wires on the ceiling could be there e.g. because of dual switch, or even if you currently don't have dual switch they would have still used three wires so that dual switch could be later installed. Then one would be neutral and the two would be lines depending on which two switches are on.You should be probably using a double insulated (double square symbol) lighting fixture which does not have PE connection at all, just line and neutral, and then find out between which two wires there is voltage when the light switch is on and connect those two.

author: themadhippy
author_rank: Super Contributor
timestamp: November 11, 2024, 05:09:53 pm
content: Quotenot under the uk regs (which aint legally binding anyway),installations that still comply with the regs they were installed under dont need bringing up to the current regs,however if your adding wiring with the new colour code then a warning notice is required at the fuseboardQuoteif you mean what we call 2 way switching then not unless its been wired in some strange way.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 11, 2024, 05:28:48 pm
content: Quote from: themadhippy on November 11, 2024, 05:09:53 pmI mean two switches that are used to switch two bulbs (or two groups of bulbs) separately within the same lighting fixture. I assume these must exist everywhere else too. There are not many ways to wire them up. It has to be one common wire (probably neutral) plus two separately switched wires (probably line) that branch off from a single line, then through the two switches.This would be the most obvious wiring arrangement for the OP IMHO, because in the past lighting fixtures were not considered appliances requiring earthing. And still most aren't.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: November 11, 2024, 05:55:42 pm
content: I'm not sure whether inspecting the fuse board will reveal much. It's still an old-style one that uses discrete fuse-wire! And as far as I remember (I'm not there right now to look), there are only two lighting circuits: one for all of downstairs, and one for all of upstairs. But I suppose it might reveal whether the lighting circuits do at least have Earth or not.As for testing voltages between wire combinations, I was thinking about that myself earlier and did an experiment here at home. I figured that there would be a small difference in measurable voltage between N-E when a circuit is under load. I tested that and was able to see approx. 1V... but only with a load of around 2000W! Just using a simple light bulb as load was useless, as there was no measurable voltage delta there. So I don't think that technique is going to be helpful for the lighting wiring.Regarding dual switching: my memory is fuzzy, but it may well have been the case that some kind of multi-switch or multi-light situation used to exist. At present the room has two lights, each with its own switch, but it wasn't always that way. I think maybe the second light might be a spur off the first, because my Dad said something about there being two wires twisted together in one of the screw terminals.Rest assured, I really am going to make absolutely sure that he does not just connect the third currently un-terminated wire to PE on the new light fixture! I am well aware that could make a very dangerous situation - hence why I'm asking these questions.

author: IanB
author_rank: Super Contributor
timestamp: November 11, 2024, 06:04:32 pm
content: Quote from: HwAoRrDk on November 11, 2024, 03:54:39 pmIt is very likely that old houses would not have PE in lighting circuits. It was usually just a 5 amp circuit going to a ceiling rose to support a pendant light. No earth was needed for those.Also, my impression was that the old colour code was red for line, black for neutral, and green for earth (if present).

author: m k
author_rank: Super Contributor
timestamp: November 11, 2024, 07:26:28 pm
content: Quote from: themadhippy on November 11, 2024, 05:09:53 pmIn my head that turns to staircase switching.Ceiling has a crown switch.

author: m k
author_rank: Super Contributor
timestamp: November 11, 2024, 07:29:56 pm
content: Quote from: HwAoRrDk on November 11, 2024, 05:55:42 pmThat is not simplifying.

author: themadhippy
author_rank: Super Contributor
timestamp: November 11, 2024, 07:54:15 pm
content: Quotewhip the switch controlling the light off and see what wires are in there,given the age of the installation it maybe wired in singles ,the live loops around the switches and a single wire goes from the switch to the light,the neutral loops around the light fittings,that could explain the 3 wires.

author: Andy Chee
author_rank: Super Contributor
timestamp: November 11, 2024, 08:13:08 pm
content: Quote from: HwAoRrDk on November 11, 2024, 03:54:39 pmI am going to assume the house is on a single phase power system.Step 1) Turn off breaker board master switch. Leave the ceiling light circuit breaker on, and a power point circuit breaker on.Step 2) Plug in a long power extension cord into a power point downstairs. Drag the socket end into the ceiling next to your wiring to be inspected.Step 3) Turn on light switch. Turn on power point. Test for continuity* between the questionable wire, and the active, neutral, & earth pins of the extension socket.*low resistance. The resistance of the house wiring and extension cord loop might not be low enough to trigger the beep in the multimeter in continuity mode.

author: Gregg
author_rank: Super Contributor
timestamp: November 11, 2024, 08:53:59 pm
content: Don't rule out the possibility that the neutral is switched. Common knob and tube wiring in North America routed the hot line to ceiling fixtures and routed neutral returns lower in the structure to all switches; somehow somebody thought it was safer that way or maybe it just used less wire.In your case the two hot wires could be spliced together at the fixture and the single return wire going to the switch.

author: Perkele
author_rank: Regular Contributor
timestamp: November 11, 2024, 09:11:37 pm
content: There are two methods:First method.If there's no RCD, go to "second method".If there's RCD, first test if it works correctly. Test it by using the button thingy. Then by tripping it on a randomly selected wall socket.If you don't know how to trip it without getting electrocuted, go to "second method".After that get a light socket (light pendant), a light bulb, some wire and terminal block/terminal strip.Find the live, take down the circuit breaker that's connected to that (live) line.Connect live to one side of light bulb. Then connect the other side to a randomly selected wire.Activate the circuit breaker.If it lights-up - congratulations, you have found the neutral. If you trip the RCD - that's the earth connection.If it does not light-up go to "second method".If you trip the fuse, oh, well, good luck then. Go to "second method".Second methodMate, get a registered and insured sparky.In those old houses you probably don't want to know what other wiring-related horrors are lurking in the walls.

author: Gyro
author_rank: Super Contributor
timestamp: November 11, 2024, 09:24:02 pm
content: If the insulation has degraded to the point where red looks brown, it could well be VIR (vitrifiedvulcanised India rubber) insulated. If so, it will be quite hardened by now and prone to cracking or completely breaking off if flexed. You might get away with appropriately coloured sleeving, but then it's a case of where do you stop. It could well be a case for an electrician.

author: coppice
author_rank: Super Contributor
timestamp: November 11, 2024, 10:04:14 pm
content: Quote from: Gyro on November 11, 2024, 09:24:02 pmIf its a very early 50s house its possible it was originally wired with rubber insulated cables, but its unlikely. Those cables have a lead sheath, and lead prices went through the roof due to the growing nuclear industry. So, PVC cables took over really quickly after their introduction at the end of the 40s. Any rubber cables still in place would be a serious safety hazard at the age they would be right now.

author: themadhippy
author_rank: Super Contributor
timestamp: November 11, 2024, 10:35:32 pm
content: Quoteive ripped out miles of old vir from that era over the years,and very little of it was lead covered

author: coppice
author_rank: Super Contributor
timestamp: November 11, 2024, 10:47:54 pm
content: Quote from: themadhippy on November 11, 2024, 10:35:32 pmI haven't seen rubber house wiring since the 80s, but the stuff I dealt with then was all lead sheathed. It was mostly from 1920s and 30s installations. What was the outer layer of the cables you have dealt with? Rubber plastered straight into a wall degraded extremely fast. I think there was a chemical reaction between rubber and anything alkaline, which plaster generally is.

author: themadhippy
author_rank: Super Contributor
timestamp: November 11, 2024, 11:17:47 pm
content: Quotebog standard rubber,in the walls normally its run in some form of metal covering,most often from that era oval split conduit

author: coppice
author_rank: Super Contributor
timestamp: November 11, 2024, 11:57:46 pm
content: Quote from: themadhippy on November 11, 2024, 11:17:47 pmMaybe that metal covering was a cheaper alternative to lead. I'm not sure I encountered that many 50s houses. There were mostly older, using lead sheathed rubber straight in the plaster. A lot of early 60s houses moved to round metal conduit with junction boxes at each node, and used red and black PVC covered wires with no secondary insulation layer. That seemed to be associated with a growth in solid concrete lower floor, spurred on by improvements in waterproof layer materials to embed in the concrete. They often relied entirely on the steel tube for the earth connection. That soon disappeared, and everything went to double insulated PVC in plaster, until they started talking about conduit again in the 80s, for no clear reason.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 12:26:48 am
content: Quoteno need the conduit is your second layer,still done today,especially in industrial installsQuoteagain perfectly normal,even today .

author: jonpaul
author_rank: Super Contributor
timestamp: November 12, 2024, 08:38:04 am
content: Try an Old electricians test light or a modern electrician test probe:OR DIY see diagram, Take any small neon lamp, 1..2 m series R, use ONE end of lamp other side to earth or hand...We have the excellent Fluke 1-AC probe.Jon

author: AVGresponding
author_rank: Super Contributor
timestamp: November 12, 2024, 11:05:41 am
content: Lots of bad, even potentially dangerous advice in this thread. First person to say something sensible was Perkele. Paraphrasing, "If you aren't sure about what you're looking at,get someone who is"Switched neutral is vanishingly unlikely.Most likely it is a loop-in wiring scheme, and no CPC. One of the black wires will be neutral, one will be switched live, and should have been sleeved/taped, but prior to EU colour harmonisation, this was not common practice.Without seeing the installation, I am hesitant to give advice,which should be the position of anyone competent. Older installations without a CPC will be flagged as a C2 at minimum, and C1 in some circumstances (C1 is "Danger present. Risk of injury. Immediate remedial action required" (the relevant circuit would be locked off/removed from the output of the circuit protective device). C2 is "Potentially dangerous - urgent remedial action required").Since the fitting you want to install needs a PE/CPC, you're going to have to rewire that circuit; adding a separate CPC in this case wouldnotbe acceptable, unless the circuit is protected by an RCD/RCBO, which I suspect is probably not the case, though I suppose you might have an older RCD protected split load board. Again, without seeing the installation, I am hesitant to give advice.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 11:55:40 am
content: Quote from: AVGresponding on November 12, 2024, 11:05:41 amWell, out of three first replies two were sensible and safe, and only one dangerous.QuoteNot at all. Working under this kind of assumption is dangerous. You must also realize that if the safety depends on correctly indicating the neutral, you are doing something wrong. So you must assume neutral being switched and you must also make sure that even if neutral and line are swapped, nothing dangerous still happens.

author: tom66
author_rank: Super Contributor
timestamp: November 12, 2024, 12:19:34 pm
content: You can use a circuit similar to a 'socket tester' which can distinguish most combinations of three wires. Unfortunately, it is very difficult to distinguish PE from N. One thing you could try is applying a 40mA load across pairs of wires. It should trip on L to PE but not L to N. If you don't have an RCD... then that is a lot more difficult and I think the only route is to actually test continuity.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 12:30:09 pm
content: Many replies concentrate1) on the initial assumption that there are Line, Neutral and Earth among those three wires2) on the idea that a lighting fixture needs these three wiresBoth assumptions are wrong, so trying to reply to the OP's question literally is useless and dangerous.An appliance which uses Protective Earth (Class 1) isextremelydangerous if miswired so it must be done correctly and with utmost care.Double-insulated appliances (Class 2) without Protective Earth connections cannot be miswired in a dangerous way at all.Therefore the OP should be using a light fixture which does not have protective earth connection, which is double insulated (double square symbol), e.g. random Google image search result:https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhtapAECiuWOtvBxUe6J2NM_xw-UwaLvXsj7unkmk4BexQuHDvumxYkF6PlndOW6roEEr_5_94ykBa_NbujvUBCMGZqxexMm6ZYBXtdGBC5CPDMRgRikKvooici5ZGgR1nxThlwtjCkxxCW/s1600/IMG_0465.JPGDouble insulated (class 2) appliance does not exposeanyof its input terminals to user even in presence of a single failure. Class 1 (earthed) appliancepurposelyexposes the user to one of its power input terminals so it should be obvious how dangerous a misidentification can be.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 12:55:36 pm
content: Quotemeanwhile in the cartels guides to codingQuote

author: nctnico
author_rank: Super Contributor
timestamp: November 12, 2024, 01:17:56 pm
content: Quote from: tom66 on November 12, 2024, 12:19:34 pmIf I encounter a situation the OP is outlining, I'd be highly motivated to take the time and rewire the whole thing with modern standard code colors. Even though that likely turns up some nasty surprises. That way I'm sure it is done right and safe.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 01:22:54 pm
content: Quote from: nctnico on November 12, 2024, 01:17:56 pmAt least this is safe advice, but it's quite expensive if the idea is to just replace an existing lighting fixture with a new one.For installing new sockets, I would tend to agree; new codes probably (depending on country) requires all new sockets are earthed; also installing new wire you can be sure about the cross sectional area.But a lighting circuit which is likely originally unearthed and for which a new Class 2 luminaire can be installed, probably not worth doing a large renovation "just because".

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 01:37:25 pm
content: QuoteSorry this is the uk,your not allowed to do your own rewires the cartels don't like it,you have to pay one of there members. Supposedly you can,but the loop hole is so tightly sewn up its cheaper to just bend over and take it.

author: tom66
author_rank: Super Contributor
timestamp: November 12, 2024, 03:55:29 pm
content: Quote from: themadhippy on November 12, 2024, 01:37:25 pmThere's no loophole, anything that involves touching the consumer unit requires the work to be signed off by at least building control. It helps to have a tamed sparky friend, I did most of my EV charger install work (drilling holes, mounting charger, pulling cable) and paid my friend the equivalent of a few beers to do the final install and test. But to an extent this is probably a good idea. There are lots of safety risks with DIY electrics and if you don't have a full appreciation of the risks electrical installations pose you shouldn't be doing work, even on your own home, because you will have visitors, or sell the home to someone else in the future...

author: tggzzz
author_rank: Super Contributor
timestamp: November 12, 2024, 04:21:50 pm
content: Quote from: themadhippy on November 12, 2024, 01:37:25 pmGiven the state of some wiring, that is a good thing.When a registered sparky was rewiring my daughter's kitchens, the bizarre existing circuits gave him electric shockstwice. There is some truly bizarrestuffout there.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: November 12, 2024, 04:26:56 pm
content: Speaking to my Dad again about this, and offering various suggestions as made here to try and determine the wiring configuration, he decided that he can't be arsed to mess around with any of that and is just going to return the new light he'd already bought and get one that is Class 2 double-insulated which doesn't require an Earth connection.We at least know for certain which pair of wires is the L+N (albeit not which is which) because of how the old light fitting is already wired, so only having to touch that looks like the sensible decision.But I did confirm what the wiring currently is, and it still makes me scratch my head:

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 04:28:35 pm
content: Quote from: HwAoRrDk on November 12, 2024, 04:26:56 pmDid the right thing IMO

author: nctnico
author_rank: Super Contributor
timestamp: November 12, 2024, 04:46:11 pm
content: Quote from: tom66 on November 12, 2024, 03:55:29 pmThe problem is not only DIY but also 'professional' builders who do electrical work on the side without having a clue what they are doing. A long time a go a friend of mine called me to fix the lamps in his new bathroom because the builder couldn't get it to work. The wiring was one big mess (some lamps where in series). The builder obviously didn't have any clue about electricity. I did manage to fix it though.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 04:59:28 pm
content: Quote from: nctnico on November 12, 2024, 04:46:11 pmThe issue with all regulated fields are the bad apples. Electricians, even doctors. There is no perfect solution for this, bad apples will always exist but at least here the problem is exacerbated by the attitude that piece of paper called "license" is sacred and work quality is secondary, it turns out that if a laymen illegally does a perfect installation which is perfectly legal in itself, they are scared to death by police, legal consequences, insurances and whatever. Meanwhile if a professional makes an actually illegal deathtrap no one bats an eye and they are very very unlikely to ever see any legal consequences because they have the paper. So I would like to see more focus on the legality and safety of the installs.So (illegal) DIY is highly frowned upon and legal installs praised to no end, and of coursestatisticallythat is true, DIY install ismore likelyto be wrong and dangerous but that average does not generalize and we should be calling out for poor and illegal professional installs. For example my illegal installs are fine.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 05:11:30 pm
content: Quotethat was meant to be an option , but £500+ to notify building control is a piss take ,and it needs to be tested by a competent electrician,there definition of competent electrician? be a member of one of the tradecartelsbodies and guess what, all the trade body's advise against signing off work by others,regardless of your qualifications and experience .Quoteand so called competent part p sparks aint immune from not having a clue either.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 05:21:52 pm
content: Quotesounds like the standard loop in loop out method the 2 blacks are the neutral in and out,the 3 browns(?) 2 go with the blacks and are the live in and live out,the 3rd brown goes to the switch and the single black is the return from the switch.the colours are different but this might help you understand thingsCredit to dave savery for the stunning artwork ,and good to see he's finally been allowed to play with the crayons again

author: tom66
author_rank: Super Contributor
timestamp: November 12, 2024, 06:14:37 pm
content: Quote from: themadhippy on November 12, 2024, 05:11:30 pmYet I've at least two electricians I've used for this kind of thing in the past.It's not a cartel, since anyone can be an NICEIC member (or one of the other groups). Annual membership fees (~£500) are not that significant compared to the course costs. And any competent sparky has 10x that much in basic test kit alone.You can still do basic work yourself as long as it is designed to BS7671. Installing sockets, changing face plates, moving stuff around all legal. Even adding a fused spur in. Can do quite a lot within that scope.

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 06:43:58 pm
content: Quotewhat else do you call a body controlling an industry? and as for membership how is a electrician who rarely gets involved in domestic work supposed to produce a suitable works portfolio?Quote£5k in test gear,yea right,mft around £600 ,voltage tester and proving unit ~£150,multimeter ~£200,and still change from a grand to get a plug in socket tester,and thats it ,if you look after the kit you wont be buying new every year

author: tggzzz
author_rank: Super Contributor
timestamp: November 12, 2024, 06:47:49 pm
content: Quote from: tom66 on November 12, 2024, 06:14:37 pmOh, but conspiracy theories are more fun and engaging. That's what matters, isn't it?They are especially beloved by those that have either been unable to join the "cartel" for whatever reason.

author: HwAoRrDk
author_rank: Super Contributor
timestamp: November 12, 2024, 06:55:20 pm
content: Quote from: themadhippy on November 12, 2024, 05:21:52 pmOh, that makes perfect sense! Thanks!There is a second light in the same room (with its own switch), so having the L+N going out again to that light would match that arrangement. Just the weird entirely non-standard colours making it nonsensical. I cast a hex upon whichever electrician did that!

author: Siwastaja
author_rank: Super Contributor
timestamp: November 12, 2024, 07:00:57 pm
content: Quote from: tom66 on November 12, 2024, 06:14:37 pmI'm surprised. Here installing a socket is one of the biggest crimes a normal human being can commit.And I think it's actually for a good reason. Sockets tend to be safety earthed and that is exactly the part which if you get wrong has real potential to kill by electrocution.Here one is still allowed to make an extension cord or replace the plug on an appliance which carry the same risk of miswiring PE. And actually miswired PEs in extension cords and appliance plugs did kill a few people every year here still in 1990's. Less today as I'm aware of, mostly because of attitude change (less DIY repair, and new extension cords being simply cheaper) and RCDs becoming more commonplace.An unearthed Class 2 lighting fixture does not have this problem, and even if it was earthed and miswired it is out of touch in the ceiling most of the time, except when you replace a bulb. But grasping a miswired dishwasher (socket, extension cord or appliance plug) with one hand while holding the earthed kitchen sink or tap with other hand have very real chances of killing, if there is no RCD.But of course traffic kills 100-1000x more, and no one is saying that only qualified professional car drivers should be allowed to drive.

author: Monkeh
author_rank: Super Contributor
timestamp: November 12, 2024, 07:11:50 pm
content: Quote from: HwAoRrDk on November 12, 2024, 06:55:20 pmIt's very likely the brown cables were, in fact, originally red (if they're rubber, the red tends to be a bit muted to begin with), and have simply darkened over time. There's nothing otherwise abnormal about the arrangement.Quote from: Siwastaja on November 12, 2024, 07:00:57 pmProfessional, no, but qualified.. yes. At least on this side of the pond, most take that pretty seriously, and the results speak for themselves compared to the US and Canada. Let's not speak of anywhere further south on that continent..

author: coppice
author_rank: Super Contributor
timestamp: November 12, 2024, 07:19:28 pm
content: Quote from: tggzzz on November 12, 2024, 04:21:50 pmSome of the worst things I've seen were done by registered electricians. I guess they are a bit less likely to do bad things than the average pleb, but they are no panacea.

author: Monkeh
author_rank: Super Contributor
timestamp: November 12, 2024, 07:20:23 pm
content: Quote from: tggzzz on November 12, 2024, 04:21:50 pmThat says as much about the electrician as the wiring.

author: tggzzz
author_rank: Super Contributor
timestamp: November 12, 2024, 07:42:57 pm
content: Quote from: coppice on November 12, 2024, 07:19:28 pmYup, it is a probability issue, not absolutes.

author: tggzzz
author_rank: Super Contributor
timestamp: November 12, 2024, 07:43:35 pm
content: Quote from: Monkeh on November 12, 2024, 07:20:23 pmI had similar thoughts

author: themadhippy
author_rank: Super Contributor
timestamp: November 12, 2024, 08:16:04 pm
content: QuoteNo conspiracy needed.take a look at your local building control and see what it says,council localish to meQuoteAnd then ring around your local niceic and napit members and see how many are members of the third party certification scheme willing to test your installation.Quotelike not doing more than 3 notifiable jobs in a year.

author: nctnico
author_rank: Super Contributor
timestamp: November 12, 2024, 09:17:09 pm
content: Quote from: tggzzz on November 12, 2024, 07:43:35 pmThat electrician clearly didn't got his shots then. One of my family members has been an electrician and at some point he had this funny conversation:- Sir, is that electrical panel live?- Yes.- Don't you get shocks then?- No. I got vaccinated to prevent that.

author: Gregg
author_rank: Super Contributor
timestamp: November 12, 2024, 10:00:20 pm
content: I am curious about how home owner’s electrical repairs or installs are policed in countries with strict regulations. Where I live it is only inspected if a permit is purchased from the usual government entity and a government employed inspector is involved.Of course there are nosy neighbors that will report a home owner either out of spite or if they suspect the home owner is not following the letter of the law. But nobody from the government ever shows up unannounced demanding to inspect a dwelling’s electrical system.Sometimes fire departments will routinely inspect commercial properties but they are mostly looking for easy targets like out of date tags on fire extinguishers to allow them to write up maximum fines for the least amount of work.In the US it is all driven by the big insurance industry which spends huge amounts to get politicians to pass legislation in their favor; by in their favor, it really means ways of denying insurance claims. The National Electric Code is written by the insurance companies and neatly packaged to get their code adopted as the legal requirements.

author: Someone
author_rank: Super Contributor
timestamp: November 13, 2024, 04:54:12 am
content: Quote from: Gregg on November 12, 2024, 10:00:20 pmWork is supposed to be done with a paper trail identifying which private contractors (linking back to their license) did which work. The overall "installation" can be assessed by a 3rd party (again private contractor) yet it's clearly not possible to check every single cable and junction in a finished property.Mostly warranted for things like insurance or public access/rental:https://www.consumer.vic.gov.au/housing/renting/repairs-alterations-safety-and-pets/gas-electrical-and-water-safety-standards/rental-providers-gas-and-electrical-safety

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2024, 08:30:58 am
content: Quote from: coppice on November 11, 2024, 11:57:46 pmI don't know about lead, but my parents' house is a similar age to the original posters and before it was rewired circa 20 years ago, it had red and black rubber insulated wire, in a rubber sheath. The lighting circuit was not earthed, but the sockets were. There was a separate circuit for the kitchen and a single ring for downstairs and each upstairs socket was a spur off the downstairs ring.Quote from: HwAoRrDk on November 12, 2024, 04:26:56 pmThat's the most sensible solution. It's certainly makes sense to avoid having to rewire the entire house. You'll probably end up with having to sort that out later.

author: tom66
author_rank: Super Contributor
timestamp: November 13, 2024, 09:35:54 am
content: The only requirement in the UK is when you go sell a house it's supposed to have an electrical installation condition report, or EICR. It's not a legal requirement but every solicitor worth their salt will ask for one. Essentially an electrician will check the condition of the installation and advise on any work needed to bring it up to standard. There is nothing stopping you buying or selling a house with a dangerous condition report, nor is there anything stopping you living in that house, though it would probably put off some buyers.

author: WatchfulEye
author_rank: Regular Contributor
timestamp: November 13, 2024, 01:31:29 pm
content: Quote from: Gregg on November 12, 2024, 10:00:20 pmIn the UK there isn't really much formal inspection for owner occupied housing. If an unqualified contractor or DIY work is done, it is doubtful that anyone would take much notice unless there was a specific reason such as buildings control getting involved for another reason (eg. As part of more extensive works) or there was a serious incident such as injury, death or fire where police or the HSE are likely to look for evidence of law breaking or an insurance company are trying to identify a negligent party.When buying or selling a property an EICR (electrical installation condition report - a standardised inspection) is desirable but not essential. Typically when buying, a buyer's legal advisor will check the buildings control register for any reason fc cially notified works and advise the buyer to check if this is consistent with thr state of the building (eg.a newly refurbished house should have an electrical works certificate on file with building control) but there is nothing to stop a sale proceeding with or without the documentation.Rented domestic properties must have a valid EICR before any new tenancy begins and every 5 years (at minimum) thereafter and a hard copy must be provided to the tenant. Enforcement varies regionally and with type of property. Some types of rented housing require a licence to let and the local authority will typically demand an up to date certificate before issuing or renewing a licence for the property.

author: coppice
author_rank: Super Contributor
timestamp: November 13, 2024, 05:47:34 pm
content: Quote from: WatchfulEye on November 13, 2024, 01:31:29 pmI thought the mortgage companies demanded them. That would affect a large fraction of home purchases.

author: Zero999
author_rank: Super Contributor
timestamp: November 13, 2024, 06:25:47 pm
content: What about insurance? I doubt you'd get insurance against fire, or perhaps liability, if the house wiring has been deemed to be dangerous.

author: coppice
author_rank: Super Contributor
timestamp: November 13, 2024, 06:34:52 pm
content: Quote from: Zero999 on November 13, 2024, 06:25:47 pmThat would assume it has failed a test, or can be found to be questionable after a disaster. Insurance applications don't ask for these documents, and many people don't have or need them.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 13, 2024, 07:12:34 pm
content: Quote from: coppice on November 13, 2024, 06:34:52 pmYeah, and they can't because there are no long-lived central registries for stuff like who did an electrical install. If there are papers like old invoices, they burn with the house. The company is likely nonexistent, whoever did the work retired, etc.If you plan to do illegal installs, the golden rules would be:(1) Only do it in your own home, where you plan on living for a long time (at least a decade maybe)(2) Learn the code, do everything so that theresultis definitelylegal(even if you doing it is not; two orthogonal things!), by the book, andsafeIf what you did is safe, then it will not cause a fire, and as a result won't be determined as a source of fire if there is a fire. If itdoescause a fire, then you deserve all the crap for doing it.

author: tggzzz
author_rank: Super Contributor
timestamp: November 13, 2024, 07:49:01 pm
content: Quote from: coppice on November 13, 2024, 06:34:52 pmNo company in the insurance ecosystem pays any attention to the application - until there is a claim. Then they examine it in forensic detail.

author: tom66
author_rank: Super Contributor
timestamp: November 14, 2024, 11:07:57 am
content: Quote from: coppice on November 13, 2024, 05:47:34 pmI don't recall our mortgage company stating that. They just wanted a survey and land registry details. Later on in the process we got EICR and the solicitor just looked it over and said nothing of concern. (The report summarises whether there are any problems in one of three categories, so you don't need to be an electrician to understand one.)

author: AVGresponding
author_rank: Super Contributor
timestamp: November 14, 2024, 01:05:36 pm
content: Quote from: Siwastaja on November 12, 2024, 11:55:40 amSpeaking from the POV of a UK sparky commenting on a UK installation, switched neutral isveryunlikely, barring incorrect termination. It should never be used, except where you are switching both L and N with a two-pole switch.DO NOT pull on wires, however gently, ESPECIALLY in a lighting circuit of this age; there is a VERY high probability of cooked and brittle insulation, which can easily flake off and cause a short outside of your view.Quote from: Siwastaja on November 11, 2024, 04:41:53 pmI don't know how lighting circuits are implemented in Finland, but that advice is not applicable to the UK, therefore POTENTIALLY DANGEROUS.Old wires do not have to be replaced unless they fail an EICR. Just the presence of old colours does NOT merit a C2 or C1, it is a C3 (improvement recommended).You would NOT have an extra conductor for a second switch, at least here. Two or more way switching is achieved at the switches, not the fitting.Having seen the OPs updated drawing, I'd say the two black wires together are N in and out, the three browns are the loop in, out, and switch feed, and the single black is the switched live, as per themadhippy's drawing, but without actually being there and testing it in person, I can't be sure, and neither can anyone else, whatever they may claim.

author: themadhippy
author_rank: Super Contributor
timestamp: November 14, 2024, 01:16:44 pm
content: Quotehow else are you supposed to see wots going on when all you're got is 2 or 3 bits of flex poking through the ceiling?

author: AVGresponding
author_rank: Super Contributor
timestamp: November 14, 2024, 03:20:07 pm
content: Quote from: themadhippy on November 14, 2024, 01:16:44 pmIf you know what you're doing (ie you're a sparks), then fine, but you better be prepared to do some rewiring if it goes badly

author: Siwastaja
author_rank: Super Contributor
timestamp: November 14, 2024, 03:40:58 pm
content: Quote from: AVGresponding on November 14, 2024, 01:05:36 pmDid you understandanythingabout the post you replied to? Did you even read it? Dismissing the warning about accidentally making the enclosure of class I equipment live and saying thatdiscussingabout this threat being dangerous is ridiculous.Yes, my advice completely applies to UK and every other country that uses any power transmission system. NEVER ****ING ASSUME* ANY WIRE IS PE.*) or use any method of measuring it you can't be 1100% sure aboutThe post you called the only correctstarted offwith accepting and amplifying the likely wrong assumption that one of the wires is PE, then going on with an elaborate and poorly laid out procedure to find which one, thankfully diluted by comments to call a sparky instead which saved the post but in the end it was useless.Again, misidentification of something which is not PE as PE and then connecting it to class I equipment PE is the most deadly thing one can do in house wiring. It is so dangerous you should not be taking even 0.1% risk. But I'm not surprised you don't understand this.Then going on to say you can assume no one would ever switch neutral in a old house is ridiculously irresponsible. It is common knowledge how old installs can beliterally anything, never assume, measure.And if you don't know what PE is, use Google.QuoteI don't know which kind of magic electricity you have there, but everywhere else if you have two separate switches switching two separate bulbs separately, you need at least three wires. You can easily deduce this being a necessity from Kirchoff laws. But I'm sure you just failed to follow the thread and misunderstood something basic as usual. You were not the only one who misunderstood, but all others understood the clarification in reply. Except you. Read the whole thread before getting on your high horse.(You also probably do not realize that one of the once popular methods to switchone(group) of lights usingtwoswitches involved switching neutral.)

author: themadhippy
author_rank: Super Contributor
timestamp: November 14, 2024, 04:49:23 pm
content: I thinks some of the confusion is language related and the term dual switch,its not a common term in the uk ,2 gang is how most here would describe it,when you add in 3 wires in to the mix its easy to assume you meant 2 (or 3 if yer a yank.why?) way switching.To add to the confusion,due to the way we tend to wire lighting circuits, a 2 gang switch will often have 4 (6 if you include earth) wires appearing at the switch.

author: IanB
author_rank: Super Contributor
timestamp: November 14, 2024, 04:53:37 pm
content: For me, a 2-gang switch is a faceplate with two switches in it. Hallways often have 3-gang switches, for example downstairs light, upstairs light, porch light. And you never guess the right switch first time

author: themadhippy
author_rank: Super Contributor
timestamp: November 14, 2024, 04:59:49 pm
content: Quotewire em all to 1 switch then yer right every time

author: flipper
author_rank: Regular Contributor
timestamp: November 15, 2024, 01:28:18 am
content: Lick them, you’ll soon find out 😂

author: AVGresponding
author_rank: Super Contributor
timestamp: November 16, 2024, 12:27:39 pm
content: Quote from: Siwastaja on November 14, 2024, 03:40:58 pmI didn't do anything of the sort. I explicity stated that UK lighting circuits do not work the way you suggested, that is all.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmIgnoring the hyperbole, I will reiterate what I said before: none of the conductors in that fitting are likely to be a CPC.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmI did not endorse the whole post, I explicitly stated that the advice of "not to touch something unless you know what you are doing" was the first good advice I'd seen.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmI understand it perfectly well, and have never suggested, implied, hinted, or stated, that anyone assume anything of the sort.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmAgain, I did not say what you claimed. I said it was very unlikely, and it is. No half decent sparky would ever do such a stupid thing. A really bad one might; I don't know any that bad, fortunately. The home owner also mightI also explicitly stated not to assume anything, and that without inspecting it personally, I also could not be absolutely sure.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmI know very well what PE is, and also the difference between PE and CPC, which apparently you do not.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmHere it would not be common practice to terminate the switched live for another fitting within a fitting. The switched live would be run directly to the relevant fitting. Again, I'm not familiar with lighting circuits in Finland; maybe it's acceptable there.Quote from: Siwastaja on November 14, 2024, 03:40:58 pmThat is not, and has never been, the case here. It is not permitted to switch circuits via the neutral, itmustbe the line/phase, or both L and N with a double pole switch.

author: Siwastaja
author_rank: Super Contributor
timestamp: November 16, 2024, 12:35:02 pm
content: Quote from: AVGresponding on November 16, 2024, 12:27:39 pmFine, show me exactly where I suggested anything about how UK lighting circuits work, and what was wrong about it.I mean, how "UK lighting circuits work" is totally irrelevant. From safety perspective, UK has the same concepts to most other countries (ignoring those of completely floating designs): protective earth or safety protective conductors (whichever term you use is irrelevant); dangerous enough AC voltages; same Kirchoff laws; classification of appliances, including lighting fixtures, into Class I and Class II devices.You commented on posts that essentially said nothing else but to never assume a wire would be a PE or a neutral and explained why, calling that advice dangerous and now you are adding that UK lighting circuits work in some other magical way, which you of course do not disclose. It appears to me you just wanted to click reply on any random post to show your own superiority without actually reading what you were responding to, as usual, and now you are digging yourself deeper into the hole as you are unable to say "oh, sorry, I replied to a wrong message" or "oh, sorry, I read that hastily".And as far as I know, PE and CPC are the same thing, just different name depending on country (just like RCD vs. GFCI) and if there is some subtle difference, it is utterly irrelevant in this context. The key lesson is the same: onappliance sidethis is connected directly to the metal chassis of the appliance and therefore anything which carries even a tiny risk of accidentally connecting this to a live* wire should be done with extreme care. And identifying "which of the three wires is 'Earth' (sic)" is exactly such risky business. Ithasto go right and must include the possibility that NONE of the wires is PE/CPC.*) Live wires being line and neutral; exactly because neutralcouldbe switched, or misidentified and thus swapped with line.Key lesson in safety critical stuff is that human beings are prone to fixating or locking into initial assumptions. If you start off with assumption that there is X within A,B,C then it is very human to pick the one out of A,B,C which isclosestto what X is. And in this case, misidentification of X is deadly.

author: nctnico
author_rank: Super Contributor
timestamp: November 16, 2024, 03:40:04 pm
content: From what I have understood from past discussions is that in the UK it is common to have a circuit in the form of a ring. So each outlet / lamp socket is supplied from two sides. This also explains the diagram posted earlier (reply #37) with the phase and neutral wires being looped through the lamp socket and the wires towards the switch are branching off.

author: SteveThackery
author_rank: Super Contributor
timestamp: November 16, 2024, 04:05:38 pm
content: Quote from: nctnico on November 16, 2024, 03:40:04 pmUsually in the UK, the sockets are fed from a ring. The lighting is not. I emphasise "usually" - as others have said, there are some eccentric installations.

author: Monkeh
author_rank: Super Contributor
timestamp: November 16, 2024, 04:29:40 pm
content: Quote from: nctnico on November 16, 2024, 03:40:04 pmThis is often the case for socket circuits, but it has nothing to do with the lighting circuit. The loop through simply moves on to the next light, it's a normal radial. You can do this at the light or the switch - the light is simply more common and standard fittings are designed for it.

author: tom66
author_rank: Super Contributor
timestamp: November 16, 2024, 04:38:12 pm
content: The lighting circuit in our house is a bit more like a mesh. I don't know who wired it, but some lamps are fed or feeding three other lights sometimes, in addition to themselves. I can only guess it happened as circuits were extended.Having said that it's not a safety risk as all that needs to be assured is that the consumer unit breaker interrupts any overload before any one wire in the system can become overloaded.I have a 6A circuit for lights, but it's done all with 1mm^2, which off the top of my head is rated to at least 13A, and all the light fittings have LEDs in them now anyway.

author: m k
author_rank: Super Contributor
timestamp: November 16, 2024, 05:48:03 pm
content: In Finland and in practice you're allowed to do much more than usually stated.You are allowed to do many things for your self.The catch is that by doing so you're many times changing things exclusively for you.In case of a house as a thing, no problem, just stay there and inform visitors.Luckily many Finns are aware enough to not remove inner walls just because.(usually roofs have some snow reserves, maybe around full of cars)Chain of feed of ceiling lights is a norm in Finland.Double light switch is wired with what you have, practically without a marking tape for after market doings.(I'll add it later stylish)So all switching cable colors can be live, including PE.Cables inside a wall can go by them selves, discrete wires must go in tubes.16A is 2.5mm2 and 10A 1.5mm2 wires.

author: AVGresponding
author_rank: Super Contributor
timestamp: November 16, 2024, 11:23:34 pm
content: Quote from: Monkeh on November 16, 2024, 04:29:40 pmTaking the feed to the switch firstcanmake it quite busy in the containment, which is why it's rarely done in domestic settings where your containment is likely capping (if anything...), though I have seen it. I prefer it, in commercial/industrial settings, as it's easier to check your supply from the board at the switch, rather than having to open up a fitting which might be 10 or more metres up.I have also seen the neutral taken to the switch first, but only by someone who thought himself a much better sparky than he actually is... His argument of "1x T+E is cheaper than 2x L+E and N(+E nowadays too)" was utter bollocks, especially in the context of him doing full weekends of overtime several weeks in a row and spending most of it on his phone looking at TikTok videos.When it comes to lighting being radial, yes. Sometimes a bit too radial, like the branches of a soddingtreeradial...Quote from: tom66 on November 16, 2024, 04:38:12 pmOof