House mains electricity issues - Page 1
Forum section: electronics / projects

author: akis
author_rank: Frequent Contributor
timestamp: May 13, 2017, 11:03:20 pm
content: What is the "neutral" wire connected to outside the house ? Is it connected to the earth at the nearest transformer station? What is the difference between the neutral and earth? What happens if you plug in an appliance that its neutral connects to earth?

author: Zero999
author_rank: Super Contributor
timestamp: May 13, 2017, 11:17:25 pm
content: 1) It depends on the earthing system. As far as I'm aware TN-C-S seems to be most common in the UK. The neutral and earth conductor surrounds the live, forming a co-axial cable, running from the substation to the property.https://en.wikipedia.org/wiki/Earthing_system2) In a modern property, the neutral goes through the RCD in the consumer unit and the earth does not. In an old property there's no difference, except it can often be disconnected by a double pole isolator where it enters the property.3) A device's neutral should never connect to earth. If it does, there's a good chance it will trip the RCD, as it will detect an imbalance in currents between the live and neutral.

author: akis
author_rank: Frequent Contributor
timestamp: May 13, 2017, 11:35:43 pm
content: I have one of those bathroom shaver sockets (with a small transformer attached). I wire it to the nearest light switch but there is no neutral in the light switch so I use the switches earth. It works fine until I try to turn the lights on. Then fireworks and fuses pop out. No RCD in the house. What happened?

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 13, 2017, 11:51:18 pm
content: You wired it wrong. So don't do any more house wiring till you know what you are doing.The neutral and active are for carrying the power.The earth is not normally meant to conduct any electricity, it is only there for safety reasons.Neutral and earth are tied together in TN-C-S in the building and connected to an earth stake, but they have different roles.Get your house wired with RCDs on each circuit. They are that good.

author: Delta
author_rank: Super Contributor
timestamp: May 14, 2017, 12:19:14 am
content: Pardon my french, but you are a fucking idiot. Please don't ever do anything like that again. In fact, PLEASE don't touch mains wiring again - that shit will kill you or someone else."There was no neutral so I just used the earth instead"! If electricity doesn't kill you for doing such a thing, a mob of angry electricians will.

author: james_s
author_rank: Super Contributor
timestamp: May 14, 2017, 04:11:54 am
content: While I agree that the OP should call an electrician for this one, I'm at a loss as to why it worked until the light was turned on. While not safe, it should technically work when connected between the live in the switch box and earth and it shouldn't make any difference whether the light is on or off.As others have already said, the earth conductor is for safety and should never be used as neutral even though they are bonded together somewhere. In the US it would be in the breaker panel but I don't recall how it's done in the UK.

author: P90
author_rank: Frequent Contributor
timestamp: May 14, 2017, 04:25:46 am
content: ahhh, Darwinism at work...LOL

author: NiHaoMike
author_rank: Super Contributor
timestamp: May 14, 2017, 05:46:06 am
content: Most likely the load side of the switch got shorted to ground by accident. Could easily happen if care is not taken to prevent the bare ground wire from making contact with exposed terminals.And here's an explanation of why using ground as return violates code even though it's electrically equivalent:http://www.repairfaq.org/sam/appfaq.htm#afwysncgtnThere is one exception - a device can use ground for return if its current draw is low enough to be within ground leakage limits *and* the current limiting is done by a device approved for bridging hot to ground such as a Y class capacitor. (That limit is very low like well below 1mA and therefore rarely sees actual use.) Even if safe and compliant, it is discouraged since they can contribute to false tripping of GFCIs/RCDs.

author: akis
author_rank: Frequent Contributor
timestamp: May 14, 2017, 07:31:20 am
content: On throwing the switch there was a shorting flash and the relevant fuse popped out at the consumer unit and fused the contacts of the light switch together so it is now permanently on.Obviously there is a short. The question is where. The electrical shaver socket has/is a transformer. It has a L, a N and an earth attached to the body of the transformer. It was very happy working with the ceiling lights off. The light switch connects a live to the ceiling light bulb (and then to the neutral). This is the circuit that was switched in and caused my contraption to short. With the switch in the "off" position, the shaver socket had worked fine for a few hours.

author: Monkeh
author_rank: Super Contributor
timestamp: May 14, 2017, 07:43:27 am
content: Put the screwdriver away.

author: akis
author_rank: Frequent Contributor
timestamp: May 14, 2017, 08:20:23 am
content: Quote from: Monkeh on May 14, 2017, 07:43:27 amDoes your comment mean that you do not have a clue what's going on? Otherwise why do you not share your knowledge? Isn't this what the forum is all about? Sharing of knowledge?

author: P90
author_rank: Frequent Contributor
timestamp: May 14, 2017, 08:32:27 am
content: I'm all for sharing knowledge... but working on mains circuit is dangerous and should not be done by those not qualified for that sort of work. Stop before someone gets hurt...

author: tggzzz
author_rank: Super Contributor
timestamp: May 14, 2017, 08:35:36 am
content: Quote from: akis on May 14, 2017, 08:20:23 amHe is indicating thatyoudo not have a clue what's going on! At least you have, belatedly, asked for advice.I certainly won't share my knowledge in this area, sinceI haven't got time to shareallthenecessaryknowledgeI cannot assess whether you have understood it or need further explanationsI haven't a clue about your specific installation, nor plansI don't want it on my head that I have said/done anything that might lead to someone's injury. While what you do to yourself is your business, in this case you might harm someone elseYou need to get taught properly by a professional.

author: SeanB
author_rank: Super Contributor
timestamp: May 14, 2017, 08:39:30 am
content: You have some wire in there on the return to the lamp with damaged insulation. Likely you also have metal conduit joining them, and a metal box the switch is in. When you pulled the switch off you put this damaged wire in close contact with a part of the conduit, or you had a small excess of wire that cracked insulation ( especially in an older house with DCC wire or very old PVC insulation, which is easy to see for DCC it has a woven cotton cover and crumbly rubber and old PVC will drip green goo) and touched the conduit or arced over on switch on.Now, you can fix this by using the old wire as a pull, to get a new set of 4 wires ( line in, neutral, return and a PE connection ) back to the likely source of the wire, in the lamp fitting. This then will get rid of the damaged wire, and give a neutral for the socket outlet, plus a better ground connection.In the light you will have to join the line to the existing and insulate it, either with a Wago connector or a ceramic wire nut and tape it up ( wire nut local code determines if you can use it, here it is an approved method with a ceramic nut) The neutral in the light will need to join 3 wires, one the neutral to the board, one the short stub to the light and the third the neutral to the switch. This also needs to be insulated as if it i live conductor, as it is one. The return wire can go straight to the lamp socket. The ground wire must be connected to the metal case of the ceiling rose using a screw, picking up the conduit there. Reason for separate ground is that the use of conduit as ground is no longer allowed, as there can be PVC conduit in there, which is not conductive, and which might have been put in during renovation, ideally the ground should be all the way back to the consumer unit and connect there to the earth busbar, but you will have to pull all the cabling along the way and replace all of it to do so, YMMV.Then you just replace the ceiling rose with the light socket attached to the new wires ( old one likely you will buy a new one), replace the lamp and cover. Switch side you connect the new switch, with the shaver socket cable fed out through a cable gland ( so as not to cut the sheath with time) and put the light switch back, turn on the circuit and check light works and shaver does as well.

author: akis
author_rank: Frequent Contributor
timestamp: May 14, 2017, 09:31:48 am
content: Quote from: SeanB on May 14, 2017, 08:39:30 amSpot on! I took the strongest torch I have and examined the return wire and sure enough the insulation has been chewed on the retaining screw that holds the light switch into its metal casing! By coincindence the electrical shaver was connected to the same circuit and I assumed the design was faulty somehow, when in fact it was the action of removing and then reinstalling the light switch that caused the problem. Or the wire had been damaged before and was looking for an excuse to make contact with the retaining screws/chassis!

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 14, 2017, 09:37:34 am
content: I just hope you don't kill anyone but yourself

author: P90
author_rank: Frequent Contributor
timestamp: May 14, 2017, 10:10:10 am
content: Quote from: RGB255_0_0 on May 14, 2017, 09:37:34 amFIFY

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 14, 2017, 10:29:07 am
content: Quote from: akis on May 14, 2017, 08:20:23 amyeah so do most of us here with lack and confusing information you provided. transformer shaver to what? can you at least draw some schematics? you tried to tap a light switch to earth, light outlet only contains live wire, a switch and a wire that goes back to the light appliance, up there, only there is a neutral line for the current to go back to the source. you turn on the switch at the outlet, both wire that you saw will be a live wires. tapping switch outlet is just as good as tapping a life line. you need to find the proper neutral path for it to go back after passing appliances.i dont agree with anyone who say put away the screwdriver or such, its a learning process. i was once there, electric shock as early as 10yrs old. but i do agree you need a guidance from experienced personnel so you'll have less chance of being a roasted turkey. please do install an RCD / ELCB, its between life or death choice, its alot lot more important than getting a proper expensive fuse for your DMM. just to get the idea, imagine a live wire accidentally touches your body during home improvement attempt, current run through the earth through your body to the leg, you are stuck there due to paralysis, and there is no other way to stop this... a proper RCD / ELCB installation will prohibit this. trust me been there. and burning house down to the ashes ground have occured from time to time around here due to improper wiring practice, the latest occurence is few days ago just few meters from where i work..before making further mod attempt, make sure RCD / ELCB is in place in fully and proper operation, otherwise.... put away the screwdriver

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 14, 2017, 10:31:53 am
content: Quote from: P90 on May 14, 2017, 10:10:10 amLet's be frank. If it wasn't for the RCD/over current protection, there could well have been a serious incident. He got protected because of the efforts of people who knew what they were doing by making and/or enforcing the rules.

author: Zero999
author_rank: Super Contributor
timestamp: May 14, 2017, 01:02:58 pm
content: Quote from: akis on May 14, 2017, 08:20:23 amAs mentioned above, we can only guess what's going on, in the absence of all the information required to figure it out.If you're offended by any of the flaming, then tough shitPeople here care far more about your personal safety and that of others than your hurt feelings, which is a very good thing, whether you realise it or not.Now I don't want to discourage anyone from learning electronics, just not on mains wiring, where a mistake could kill someone. Get yourself some AA batteries, a battery holder, a cheap multimeter (don't use it on mains though) some LEDs, resistors and switches and experiment with them. Even that's not perfectly safe, since the short circuit current from some batteries can be high enough to burn you but the limited energy in a small battery means no harm will result. You can then think about things you can do to make it even safer, such as adding a fuse or a PTC resistor if you want something resettable.

author: tggzzz
author_rank: Super Contributor
timestamp: May 14, 2017, 01:28:57 pm
content: Quote from: Hero999 on May 14, 2017, 01:02:58 pmQuite right tooPersonally I care far more that he might hurt thenext personto use/investigate one of his "installations". If he kills himself, then the consequences is merely to have improved the species.

author: Ian.M
author_rank: Super Contributor
timestamp: May 14, 2017, 01:38:49 pm
content: The O.P. cannot legally do this sort of electrical installation work in the UK.To summarise: under Part P of the Building Regulations, all electrical work other than like for like replacement of fittings and wiring on protected circuits, 'downstream' of the protection, not in restricted zones (e.g wet areas),requires notification to the local building authority, and if notifiable, has to be performed by a registered competent person or fully inspected by a registered qualified electrician.If the shaver socket is in a bathroom, it is likely to fall in a restricted zone, the regulations for which are quite complex, and it is obvious that the O.P. has no hope of passing the competent person certification without extensive formal training.The UK Wiring Regulations aren't quite as draconian as the Australian ones, but they are headed in that direction. The wiring colour code changed when the regulations were changed to restrict D.I.Y, and wire to the old colours is no longer sold, so any subsequent spot check can easily see if you have replaced or added circuits, and unless they are not notifiable or you have the right paperwork showing they were performed legally, at the minimum you will have to have a full electrical inspection, and at worst there could be considerable fines.As such the only advice we can legally and ethically give is:DON'T MESS WITH IT YOURSELFEMPLOY A REGISTERED QUALIFIED ELECTRICIAN

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 03:11:59 am
content: Yeah that's ridiculous. I'm perfectly ok with requiring an inspection, but damned if I'm going to hire an electrician to do electrical work in my own home. It's something that I personally am proficient at, I've been trained by a family member who spent his career as a licensed electrician and I've got a good understanding and a lot of experience. It just isn't something I chose as a career path.I think that while the intent is good, in practice requirements like this don't do anything to stop people who know just enough to be dangerous, they will still attempt to do it, only they will not have access to proper supplies, books and knowledgeable advice or an inspection. I've certainly seen plenty of examples of people who should not have tried to do electrical work. My house was originally built with an unfinished basement which was finished by the original owner. I had to redo much of the wiring because it was so badly done. All the light switches were on the neutral, all of the receptacles had been installed with the wires trimmed so short they would just barely reach to those horrid spring loaded backstab terminals. The receptacles were all the cheapest crap available and they were so loose plugs wouldn't stay in. When I pulled them out of the boxes several of them fell apart.

author: akis
author_rank: Frequent Contributor
timestamp: May 15, 2017, 06:06:38 am
content: Many thanks for all the comments of caution and others.To summarise :1) A fixing screw on a light switch cut into the insulation of a return wire making contact, and when the light was turned on it shorted live (L) against the casing/screw which was earthed (E). The light switch fused. The fixing screw has had a chunk taken off. That was a sloppy work on my part forcing a screw in like this when I clearly felt that the switch was not fitting in properly but it was very late at night and was too tired having worked all day.2) At the same time I had also connected a bathroom shaver socket to that light switch. When the main fuse tripped I thought it was something related to the shaver socket and I asked here. But it was simply a fixing screw grinding on a live wire.3) Someone asked why did I chose that light switch as a source of power. Because it is the nearest and only source of power in that location. The light switch lacked a N and so I wired the shaver socket's N to the E of the light switch. In future I will attempt to draw a new line into the light switch. Please note I have not connected the house's N to E.4) In this very large and unnecessarily hostile thread, there are, I think, just two messages referring to what might actually be wrong in connecting N to E inside the house, and I think there is only one message, posted late on the thread, on why it should not be done. To explain it for anyone that wonders, if you or an appliance connects N to E, inside the house, and if you then somehow remove/disconnect the E from the consumer unit and from all the other places that the house might be earthed at (eg water pipes etc) then you are in danger since the house is no longer earthed and your earth becomes live (through this appliance) thereby killing you when you say try to turn the tap on in your kitchen. Something like that. Just to make it clear, I did not connect N to E and there is no N at that location.5) There are PSUs and other gadgets and appliances, that do legitimately (?) connect L to E, so long as the leakage is very small - obviously smaller than the 15mA, or so, that would trip the RCD.6) In Germany there is at least two places (hotels) I have visited that have power sockets inside the bathroom, next to the sink, and I have used them to boil my kettle and my coffee maker which was resting on the sink. Either those hotels have illegal installations or they just do not care. Similar power sockets found in other EU countries I have visited, most modern hotels, above and below the sink in the bathroom. There are also other power sockets so you can plug in your washing machine in the bathroom. My bathroom (in UK), which is larger than a small bedroom, has no power sockets.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 06:31:56 am
content: Quote from: akis on May 15, 2017, 06:06:38 amThat doesn't matter, you've still created the potential for a dangerous fault. You are passing current through a non-current-carrying conductor with only the primary winding of a transformer to limit the current.Sorry, but I'm not going to coddle you: You should not be doing mains wiring. You don't know the regulations or, quite clearly, the reason behind them, and your installation is sufficiently out of date to not make any attempt to protect you from yourself, let alone others.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 15, 2017, 06:42:34 am
content: OP is lucky to be alive,not injured,no ladder fall rash,no metal and plastic shrapnel lodged in eyes,no skipping heart beat..and butt hurt that VERY concerned EXPERIENCED people here had an"unnecessarily hostile" ?!!go for seriously screwing up ? Please...How can you be sure the house wiring is not a total DISASTER waiting to happen, if others before you attempted similar cheapskate wiring practices too?Imagine a child in this scenario,bored and poking about, the kid gets silently toasted whilst the partners are bonking their brains out in the closed bedroomor on the computer giggling and sniping on Facebook.You need to get an experienced electrician in there YESTERDAY to give you the bad news,and a good price to stress test the entire installationto find and undo all the accumulated cheapskate wiring fiascos,end of story.

author: P90
author_rank: Frequent Contributor
timestamp: May 15, 2017, 07:08:01 am
content: I was doing some work at my friends house and discovered that some genious had added an additional light fixture in the living room by using the existing switch ground as a neutral, and the neutral line as a second hot to the new fixture. So, it appears these people are everywhere among us...

author: Electro Detective
author_rank: Super Contributor
timestamp: May 15, 2017, 07:20:50 am
content: Quote from: P90 on May 15, 2017, 07:08:01 amI eliminated some of the same vaGenius work years ago found lurking at 'immediate family' houses, I don't need the drama.Yes, these cheapskates are everywhere, and unfortunately even the latest high powered 'They Live' glassesdon't show up their handywork,only a suspicious non assuming person with electrical knowledge and proper test gear can ferret it out.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 07:25:53 am
content: Taking your points slightly out of order.The thread is hostile because dicking around with mains electricity is dangerous if you do not know what you are doing. Wooden box dangerous for you or someone else in your house, and the good denizens f this forumwillget worked up about that sort of thing.By using protective earth as the return for an appliance you risk making large amounts of stuff live if there is a separate fault in the earth wiring. Connecting E-N in the property is unlikely to cause any problems and, indeed, is done with some earthing schemes, but don't do it anyway.There are different rules on the continent and sockets are allowed in bathrooms as long as they are not in zone 0/1/2.Yes, there are rules about L-E leakage so a very small amount is allowed. You cannot extrapolate from that to "it is generally OK to use protective earth as a regular return connection".

author: P90
author_rank: Frequent Contributor
timestamp: May 15, 2017, 07:26:44 am
content: Quote from: Electro Detective on May 15, 2017, 07:20:50 amShe told me this genius that installed the said can light fixture was a so-called electrician... that's scary...

author: tggzzz
author_rank: Super Contributor
timestamp: May 15, 2017, 07:36:23 am
content: Oh dear.Quote from: akis on May 15, 2017, 06:06:38 amYou continue to miss the root cause of what is "wrong": someonethinkingthey understand X when clearly theydo notunderstand X - and finding all sorts of ways of avoiding that realisation.In the face of that and in the light of the potentially lethal consequences, people become more insistent and blunt. That is not being "hostile".QuoteName them.QuoteAnd why is that relevant to what you have attempted to do?

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 15, 2017, 07:54:31 am
content: Using Earth as a return supply not only has EMI repercussions but could make every grounded metal fixture an alternate path. So you can be using your shaver and injure someone else.

author: P90
author_rank: Frequent Contributor
timestamp: May 15, 2017, 08:01:04 am
content: Quote from: RGB255_0_0 on May 15, 2017, 07:54:31 amyup, you get a break in the ground connection somewhere down the wire, and suddenly your metal toaster housing is now energized.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 15, 2017, 08:15:35 am
content: "she'll be right lads, it's only three wires, not rocket science.. "

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 08:25:54 am
content: I'm not sure how this relates to the original post but since it came up I'll comment on it. The UK is the only place I've visited where mains sockets in bathrooms are not allowed. Throughout North America it's standard practice, there will always be a socket in the bathroom so you can plug in a shaver, hair dryer, electric toothbrush charger, curling iron, whatever. As of the late 70s these are required to be GFCI (RCD) protected but they're not isolated. It's been this way forever and it's not as if people are dropping dead every day. It has been far safer since "hot chassis" radios went away, there used to be incidents where someone would reach out of the shower/bath to adjust the radio and contact a live metal shaft with a damaged or missing knob.Now regarding the original topic, you guys are all correct of course but I will agree with the OP that some of you are being unnecessarily rude. There is no reason to call someone expletives even when they are wrong, there are more tactful ways of telling them that they are more likely to listen to. Obviously the OP should stop and preferably hire an electrician, but this sort of work is not out of reach of a relative beginner *provided* they take the time to read a book and understand the fundamentals, but clearly that has not been done here. It is never ok to use the earth ground as neutral to power a load. It may not be too difficult to drop a new run from the light or from a socket on the opposite side of the wall if there is one but I do echo the concerns of not proceeding until you know how to do it properly and why. This stuff really does have the potential for lethal consequences, particularly in 240V land and even more so in a damp location like a bathroom.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 08:28:33 am
content: Quote from: james_s on May 15, 2017, 08:25:54 amExcept they are.

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 08:40:24 am
content: Quote from: Monkeh on May 15, 2017, 08:28:33 amThat's news to me. The only thing close I ever saw in any of the homes I was in was a low power transformer isolated 110V shaver socket of the sort discussed here. Even the light switches were always outside of the room, and the exhaust fans all had pull cords dangling from the ceiling. It worked fine but it was definitely unusual compared to what I'm used to.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 08:42:11 am
content: Quote from: james_s on May 15, 2017, 08:40:24 amMost 'electricians' can't be bothered with the great complexities of simple measurement to meet the regulations, so they chicken out and just don't install things inside the room. And those are the ones who are bright enough to realise it's allowed, then we have the large number who think it's not.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 15, 2017, 08:43:18 am
content: Quote from: james_s on May 15, 2017, 08:40:24 amIt's somewhat legacy considering the RCD standalone outlets you can get now but even RCD/GFCI devices do not protect you from 2-wire appliances being mis-used. So I do not see a problem with denying full mains outlets in bathrooms.Besides, our bathrooms are normally smaller, and dressing areas are normally in bedrooms here.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 08:46:34 am
content: Quote from: Monkeh on May 15, 2017, 08:28:33 amExcept that, as they have to be 3m from zone 1, most UK bathrooms are not large enough to allow them.

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 08:47:54 am
content: I don't have a problem with denying them, I just observed it as as being unusual compared to what I'm used to since I don't think I've ever seen a bathroom in the US that didn't have a socket in it. Even the smallest ones with just a toilet and sink will have a socket.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 08:48:42 am
content: Quote from: james_s on May 15, 2017, 08:47:54 amA toilet and a sink does not a bathroom make - no problem putting a socket in there.We can have shaver sockets installed rather closer, most people just don't.

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 08:51:08 am
content: Well in the US it's still called a "bathroom" even if there's no bath. That's the standard term used to describe any room with a toilet in it. Technically I think those are called a "1/3rd bath" if you look at house listings. A half bath means there's a toilet, sink and shower. It can be debated whether that makes any sense at all but that doesn't change what is, I didn't come up with the names.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 15, 2017, 09:13:48 am
content: Careful, electricity is not really a large killer in western society.A lot of that is because of the draconian rules. For good or bad that's just the way it is.This guy has hundreds of posts and is interested in electronics so try not to be so rude.Ask him to correct his ways and point out why, I think that is enough.To put it in context, suicide, automobiles and bad diet are far far far bigger killers.Btw i have seen the handiwork of plenty of bad and non electricians, I guess some of the temptation to DIY is the additional compliance costs of the electricians.Here's an electrical rules test for our Aussie sparkies. I haven't looked hard but I can't remember a rule against it, it just seems wrong.3 phase 20A Neutral and earth gpo.Is it mandatory to wire the neutral pin? Can someone point me to the rule in AS3000?I found some today with only 3 cores and earth run to them.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 09:15:49 am
content: Common sense alone says if it has a neutral pin it should be connected. They make them without, or at least the normal ones everyone else uses.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 15, 2017, 09:20:42 am
content: Yes common sense says that, so I think it will be in the rules.But where?

author: helius
author_rank: Super Contributor
timestamp: May 15, 2017, 09:21:33 am
content: QuoteWhich makes it confusing as to what to call a room with a sink but no toilet: in practice a variety of terms are used, like waiter's pantry, lavatory, wet bar, or scullery.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 09:23:25 am
content: Quote from: HackedFridgeMagnet on May 15, 2017, 09:20:42 amHell if I know. Over here it'd probably fall under the requirement to install according to manufacturers instructions (this applies toeverything).

author: akis
author_rank: Frequent Contributor
timestamp: May 15, 2017, 09:28:01 am
content: Quote from: tggzzz on May 15, 2017, 07:36:23 amI did not think I was doing anything "right" or "wrong". That is why I asked here. I have also said that I will rectify the issue.QuoteOne would and should say, "This is potentially hazardous for this and this reason". Not, "I hope you kill just yourself" and any of the other clearly arrogant and hostile quotes. It seems this forum is inhabited by too many unemployed electricians perhaps?QuoteLarge numbers of adaptors. We have had two threads discussing these here in the past.https://www.eevblog.com/forum/testgear/laptop-power-supply-adaptors-mains-on-the-output!/msg417774/#msg417774https://www.eevblog.com/forum/testgear/smps-leakage-currents-present-in-the-output-pins/msg592438/#msg592438QuoteAnd why is that relevant to what you have attempted to do?I was referring to some earlier post that mentioned bathrooms. As part of this discussion of what electrical work you should and should not do in a bathroom.I have since done a search on "shaver socket bathroom" and there are dozens of similar posts to mine dating back decades.I would ask the authors to delete all the arrogant and unnecessarily hostile posts and then this thread might offer some merit in years to come.

author: HackedFridgeMagnet
author_rank: Super Contributor
timestamp: May 15, 2017, 09:32:33 am
content: Sorry to sidetrack thread. - found it, in 'verification'. that's enough for me.8.3.7.2 ResultsProof that all active, neutral and protective earthing conductors in theelectrical installation are correctly connected to the corresponding terminalsof electrical equipment so that-etc.Yes I was thinking of the manufacturers instructions one too.good now I have a reason to rip them all out.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 09:33:51 am
content: Ah, verification and testing. Something the septic tanks could learn a thing or two about!

author: abraxa
author_rank: Frequent Contributor
timestamp: May 15, 2017, 09:57:32 am
content: QuoteFor the sake of completeness: this is because in Germany, bathrooms must be protected by RFDs/GFCIs in the main breaker box - this way, standard outlets can be used and no built-in RFD/GFCI is needed. Since 2007, *all* newly installed residential circuits must be protected by RFDs/GFCIs (except immovable lighting), not just the bathrooms. With that, it doesn't matter what you connect or where you connect it, it's always safe.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 09:58:14 am
content: Quote from: akis on May 15, 2017, 09:28:01 amYes, lots of equipment has EMI suppression caps from L-E and a small amount of leakage is allowed750uA for hand held class I appliancesUp to 3.5mA for certain Class I appliances such as computers.250uA for class II (to any exposed conductive part of the case).It does not mean it is a good idea to connect your shaver from L-E.

author: Zero999
author_rank: Super Contributor
timestamp: May 15, 2017, 10:01:08 am
content: Quote from: Monkeh on May 15, 2017, 08:48:42 amWhatever you call the room, the wiring regulations in the UK prohibit electrical switches and sockets within a certain distance of a sink, tap, bath, shower etc. unless they are adequately sealed or under a certain voltage. I can't remember the exact figures and theycan'tcanbe found using a search engine if you're interested. Sockets for shavers are allowed, providing they contain an isolation transformer.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 10:30:32 am
content: Quote from: Hero999 on May 15, 2017, 10:01:08 amBasically, lighting:Zone 0 (within bath or shower tray). IPx7 and SELVZone 1 (directly above Zone 0 to a height of 2.25m) IPx4Zone 2 (within 60cm horizontally from Zone 1 & 50cm vertically) IPx4Sockets - >3m from Zone 2, as long as no direct jet of water likely.Isolated shaver sockets are allowed in Zone 2 IIRC.As to continental rules I think sockets were allowed in France even before RCDs became mandatory. RCDs have been mandatory in the UK since 17th edition (2008, again IIRC).Disclaimer: I'm not an electrician so check the regulations yourself. As has already been pointed out all installations in Zone 0-2 fall under "Part P" so are not considered suitable for DIY work.

author: P90
author_rank: Frequent Contributor
timestamp: May 15, 2017, 11:07:41 am
content: Do they still use those silly ring circuits in the UK?

author: madires
author_rank: Super Contributor
timestamp: May 15, 2017, 11:19:50 am
content: Quote from: abraxa on May 15, 2017, 09:57:32 amBut we also got security zones with specific requirements defined. So you aren't allowed to place a mains outlet above the bathtub for example. And there's the right of continuance for old installations which comply with the requirements back then when the installation was done.

author: Gyro
author_rank: Super Contributor
timestamp: May 15, 2017, 11:37:11 am
content: Quote from: P90 on May 15, 2017, 11:07:41 amNothing silly about them - and no reason to sidetrack the tread further either.

author: akis
author_rank: Frequent Contributor
timestamp: May 15, 2017, 12:05:09 pm
content: Quote from: Monkeh on May 15, 2017, 06:31:56 amOK, thinking aloud, please do not shoot.I think I spotted an internal fuse in the shaver socket while installing it, but actually am not sure. May have been a thermistor to save the windings if you plugged in your hair dryer.When I started this I assumed that my "earth" and my "neutral" were synonymous, ie connected together at the consumer unit or somewhere else in the house (which, they actually are, at the consumer unit).Now, if we had an appliance that uses the E as N (say it had a fault). Would that then bypass the electricity meter and thus steal from the electricity company even if it is uA or mA ?

author: Zero999
author_rank: Super Contributor
timestamp: May 15, 2017, 12:15:38 pm
content: Quote from: akis on May 15, 2017, 12:05:09 pmThe transformer has to have some protection against overload and overheating. Whether the protection is resettable or one-shot, depends on the quality of the unit. A very good quality unit will have both a thermal fuse (non-resettable) and a bi-metal strip or PTC fuse for over-current & thermal protection.QuoteNo, since the meter only measures the current through the live conductor and voltage from live to neutral/earth.

author: IanB
author_rank: Super Contributor
timestamp: May 15, 2017, 02:31:03 pm
content: Quote from: akis on May 15, 2017, 12:05:09 pmIf they were to be equivalent, then why would they have separate names, separate conductors, and separate wiring colours? Failure of critical thinking here, IMHO.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 02:48:09 pm
content: A minor correction and addendum to my post above (might as well get it right).Sockets are allowed as long as > 3m from Zone1Shaver sockets to BS EN 61558-2-5 are allowed in Zone 2 even though they do not meet IPx4.There is a useful reference card herehttps://www.tlc-direct.co.uk/Technical/DataSheets/Firstlight/Zones.pdf

author: tggzzz
author_rank: Super Contributor
timestamp: May 15, 2017, 02:50:01 pm
content: Quote from: IanB on May 15, 2017, 02:31:03 pmNicely putNot the only failure of critical thinking, either

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 03:08:07 pm
content: Neutral is bonded to earth at the panel, it goes to the same place but that does not make it equivalent. The earth wire is a safety device and is not to be used to carry return current.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 03:25:55 pm
content: Quote from: james_s on May 15, 2017, 03:08:07 pmDepends on the earthing scheme. With TT or TN-S arrangements then neutral is not bonded to earth at the consumer panel.

author: james_s
author_rank: Super Contributor
timestamp: May 15, 2017, 03:39:43 pm
content: I should have specified, in the US neutral is bonded to earth in the panel, elsewhere it is still bonded somewhere. I am not and should not be taken as an authority on UK wiring practice although wiring in "other" places is something that interests me.

author: P90
author_rank: Frequent Contributor
timestamp: May 15, 2017, 03:51:02 pm
content: and in the US the ground is tied to the neutral bus bar at the main service panel, but ground and neutral are isolated at any subpanel.

author: akis
author_rank: Frequent Contributor
timestamp: May 15, 2017, 03:57:23 pm
content: Quote from: james_s on May 15, 2017, 03:39:43 pmI have checked and noticed a connection to the neutral at the panel and before the electricity meter, but I do not know and cannot be sure if there are not any more such connections in the house. Theoretically any plugged in appliance or hard wired installation could by design or by fault be connecting neutral to earth inside the house. How would you know - unless you have an RCD which older houses may not have.There are also connections of water and heating copper pipes that are buried in the concrete/ground, run outside to the garage and to the bottom of the garden tap. I am not sure if these provide some earthing. But if they do, maybe this eliminates all the potential hazards we discussed above?

author: helius
author_rank: Super Contributor
timestamp: May 15, 2017, 04:00:05 pm
content: Quote from: james_s on May 15, 2017, 03:39:43 pmThis article is pretty good:https://en.wikipedia.org/wiki/Earthing_systemIn the IT system neutral is not bonded to anything.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 15, 2017, 04:35:23 pm
content: Quote from: helius on May 15, 2017, 04:00:05 pmThere is also a fairly clear reference herehttp://electrical.theiet.org/wiring-matters/16/earthing-questions.cfm?type=pdf

author: RukyCon
author_rank: Contributor
timestamp: May 15, 2017, 05:47:29 pm
content: In my house, there's a outlet that has no ground running to it, it was done by the original owner.I think it would be a good idea to ground it someday.

author: Monkeh
author_rank: Super Contributor
timestamp: May 15, 2017, 06:01:39 pm
content: Quote from: Hero999 on May 15, 2017, 10:01:08 amNo, a sink doesnotapply. You do not stand in a sink.Quote from: akis on May 15, 2017, 12:05:09 pmA fuse will not protectyou. And no, earth and neutral should not be connected at your consumer unit - if they are, you have yet another fault in your installation.Quote from: akis on May 15, 2017, 03:57:23 pmWater pipework is not used as a ground conductor, it is only bonded. Andnothing eliminates the potential hazards except wiring the system correctly.

author: tggzzz
author_rank: Super Contributor
timestamp: May 15, 2017, 06:27:36 pm
content: Quote from: Monkeh on May 15, 2017, 06:01:39 pmIt is a shame that style is an appropriate response to a rather, um,disappointingquestion/statement. If nothing else, beginners that stumble on this thread sometime in the future are now alerted to the quality of some of the posts.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 16, 2017, 01:09:18 am
content: Quote from: akis on May 15, 2017, 03:57:23 pmneutral SHOULD NOT be connected intentionally to earth wire. if you aware of such installation in your house, please rectify that. but as previous warning, put away the screwdriver before installing RCD. once installed, if your house wiring is at fault, RCD will trip at the first run, then you'll know something is wrong... if RCD is not tripping, you have a better chance that your house wiring is ok.earth wiring is and should be an isolated system from mains L and N, its sole purpose is only for protecting your arse. and any devices/metal connected to it. if you see an earth wire is connected to water or copper pipe, not because the pipe will be used as earth return path, but meaning that, that pipe is to be protected from live connection. meaning you should be safe when touching the pipe and then live wire got connected to it, but only if RCD is already installed. earth return path is usually just outside your house consisting of a metal giant nail buried at some depth in earth and then buried by cement on top so no fool can play around with it...refer to page 27 (EARTHING OF ELECTRICAL INSTALLATIONS)...http://st.gov.my/index.php/en/download-page/category/94-guidelines-electricity.html?download=347:guidelines-for-electrical-wiring-in-residential-buildings

author: mtdoc
author_rank: Super Contributor
timestamp: May 16, 2017, 01:48:58 am
content: Quote from: Mechatrommer on May 16, 2017, 01:09:18 amAs others have noted, in the USA, neutral is bonded to earth at the service entrance (and no where else). In older homes the earthing was often done using buried water pipe instead of a dedicated ground rod.

author: Monkeh
author_rank: Super Contributor
timestamp: May 16, 2017, 01:49:51 am
content: Quote from: mtdoc on May 16, 2017, 01:48:58 amWhich is not relevant.

author: mtdoc
author_rank: Super Contributor
timestamp: May 16, 2017, 02:00:07 am
content: Quote from: Monkeh on May 16, 2017, 01:49:51 amI was responding to and clarifying Mechatomers unqualified statements:QuoteandQuoteWhich as stated are not fully accurate.

author: IanB
author_rank: Super Contributor
timestamp: May 16, 2017, 02:09:32 am
content: It is of course interesting how earthing systems vary from one country to another. For example, descriptions of protective earthing in the UK tend to say the neutral is bonded to earth "at the substation". However, here in the USA it is fairly traditional that there is no substation. Very often the transformer is in a metal can at the top of a wooden pole outside the house. It is far away from the ground and in any case wood is not a very good conductor. This state of affairs probably has a bearing on the different traditions in the two countries.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 16, 2017, 02:25:07 am
content: Quote from: mtdoc on May 16, 2017, 02:00:07 amin your 110V dry country only... in 220V wet country, you may be surprised if you get a shock, people died. maybe you can learn from 220V country code conduct and make your own proper substation (proper return path through RCD in the house. what i linked and stated is in accordance to our energy committe guideline, not some found by luck method. you country doesnt enforce it not necessarily means it is safe or valid... ymmv..Quotego figure i dont have time for...

author: Ian.M
author_rank: Super Contributor
timestamp: May 16, 2017, 02:41:46 am
content: In the UK, for domestic consumers, EITHER the supply company provides an earth (TN-S or TN-C-S systems) OR it does not, making the earthing system entirely the consumer's responsibility (TT). Any Earth-Neutral bond on the supply side of the meter (TN-C-S), is the supply company's responsibility, as all the L and N terminals up to the meter are sealed with tamper-proof seals, so any such bond has to have been approved by the supply company before they applied the seals. OTOH there should *NOT* be an Earth-Neutral bond after the meter - the installation either uses the Earth as supplied by the supply company or the L and N *MUST* pass through a RCD and then a local Earth electrode system (TT) can be used (and in some cases - e.g. feeds to caravans & boats - is required even if the incoming supply offers an Earth terminal). This differs considerably from American practice where IIRC it is more or less standard to have an Earth-Neutral (or in American Ground-Neutral) link in the main panel, but it is prohibited in sub-panels or elsewhere downstream of the main panel.

author: mtdoc
author_rank: Super Contributor
timestamp: May 16, 2017, 02:44:48 am
content: Because there is a variety of earthing systems employed in different countries (and no, the US is not unique) I think it is important to qualify statements and not assume that readers know that what one reads may not apply to their country. That in itself could prevent someone from doing something dangerous.Oh and FWIW, many parts of the USA are very wet and there is a National Electrical Code that is very safety focused and strictly enforced in most juristictions.

author: Monkeh
author_rank: Super Contributor
timestamp: May 16, 2017, 02:51:56 am
content: Welp, now we're off the rails and rolling downhill.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 16, 2017, 02:53:24 am
content: i dont know, but if one (non competent) take earthing at his own hand, there could be a tremendous waste of energy if there is short L to E, without any meter or panel telling or tripping it (you only know it from the bills you pay next month), there could be also fire hazard, not to mention the earlier mentioned life threatening issue. maybe the 110V countries took this lightly as death toll is probably on low side

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 02:54:16 am
content: The transformer that supplies my house and the one next door is in a small cabinet in the bushes near the sidewalk, this is typical of neighborhoods with underground power.I don't know what constitutes "wet" but here in the Northwest corner of the US there is an area classified as rainforest, and the area I live is wetter than average, notorious for gloomy gray skies and drizzle. The climate here in the Seattle area is very much like that in much of the UK. It's a big country and when it comes to climate we have a little of everything.

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 02:57:11 am
content: Quote from: Mechatrommer on May 16, 2017, 02:53:24 amWe have 240V too, although it's 120-0-120 center tapped. It's not possible to bypass the meter or the breakers by messing with the earth ground. You could tap off the live conductor and wire something between that and a separate ground rod driven into the yard and the meter will still register. If there's a potential way to steal electricity, you can bet somebody has tried it. The power companies are not stupid, they don't make it easy.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 16, 2017, 03:04:50 am
content: Quote from: james_s on May 16, 2017, 02:54:16 ami was refering to atmosphere relative humidity where probably it will affect your body and finger conductance. heavy rain may not necessarily affect average daily RH. one thing for sure, wet hand on a live wire is much more painfull than a dry hand.Quote from: james_s on May 16, 2017, 02:57:11 amstealing around here is easy, just do the job before the meter (tap both L and N), i'm guessing in coutries where N is non existence, just tap the L before the meter, no? but well, i'm not into stealing stuffs.

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 04:31:14 am
content: During times of heavy rain the RH goes way up, at times it can get almost tropical feeling when we have the occasional summer rain storm.I suppose it would be possible to tap off before the meter, I don't think the grounding scheme would affect that though. Pretty sure they have ways of detecting it too although I don't know for sure as I don't mind paying for my power. I think it's mostly people who are growing drugs and need large amounts of power to run grow lights that try to bypass the meter. Excess power consumption is one of the things that tips off the authorities.

author: Nusa
author_rank: Super Contributor
timestamp: May 16, 2017, 05:08:02 am
content: Quote from: IanB on May 16, 2017, 02:09:32 amActually those USA pole transformers should be grounded to earth at the pole. If you take a close at a transformer pole you'll probably notice the wire coming down it, probably under a wood molding that both protects and camouflages it.Now back to your regularly scheduled program about UK-specific electrical safety and laws.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 16, 2017, 05:20:13 am
content: It is interesting how many of the comments on this thread are recital of code, and how few discuss the thoughts behind the code. After reading the links and the thread a beginner should begin to understand that the intent of the earth/ground connection is to minimize hazard under fault conditions. While it is implied, none of the comments or references directly states that there is an underlying presumption that those protected are standing on a surface that is likely to be at earth potential. If this surface is conductive and a potential appears between the case of the equipment and ground bad things happen.The different systems in the UK and US likely are at least partly the result of geography and climate. In the soils of the UK, with the generally damp climate there is likely to be a low impedance between any service location and the bonding point at the substation. The surface that the protected person is standing on is very likely to be at the same potential as the bonding point, even if it is dozens or hundreds of meters away. This is true in large parts of the US, but unfortunately very untrue in other, also large parts. Dry soils and/or those with little ionic or metallic content can have extremely high impedances. I have observed potentials of half the line voltage between the local dirt and a bonding point a couple of hundred meters away. This is likely the reason for the requirement for local bonding. Those same soil conditions make it very challenging to actually get an earth connection. Fortunately they also are a strong limit on the fault currents that can develop through body contact with the floor so it is a somewhat self compensating problem.There is no substitute for following local code requirements. They are the result of decades of experience in what works and what does not. But I find it easier to understand and remember the code requirements when I have some understanding on why they have occurred. Simple things like wire size relations to current flowing in a circuit are obvious, but some are more subtle.

author: Unknown
author_rank: Unknown
timestamp: May 16, 2017, 06:08:15 am
content: Quote from: james_s on May 16, 2017, 04:31:14 amPeople do seem to try a lot of ways to steal power:Grappling hooks:https://www.wired.com/2010/06/military-bat-hook-sucks-free-power-from-overhead-lines/(military version of an urban legend of people tossing grappling hooks onto overhead lines)Induction:http://hackaday.com/2017/04/10/wirelessly-charge-your-phone-from-high-voltage-power-lines/Meter bypass:https://www.youtube.com/results?search_query=meter+bypassMore meter bypass (screwdrivers!), jumper cables:http://www.news4jax.com/news/local/thousands-stealing-power-from-jea-their-neighborsMore jumper cables:http://www.eastvalleytribune.com/business/utility-providers-boost-efforts-to-stop-theft-of-electricity-water/article_10b3438a-6234-11e0-8db1-001cc4c002e0.htmlOf course, my all time favorite:

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 16, 2017, 03:53:32 pm
content: It is interesting that none of the power thieves I have seen documented even approximate the appropriate electrical code in their connections. While code installations are clearly safer, the death rate among power thieves is not so high as to discourage the practice, or to improve their methodology. I have seen reports of death and injury among power thieves, but it isn't all that common.

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 04:11:00 pm
content: One can often get away with some really sketchy stuff. I have certainly rigged up temporary stuff that would make an electrician cringe. That said, I learned some of that stuff from my uncle who was a licensed commercial electrician. The power cord with alligator clips on the end for example.When it comes to power thieves, I don't think they're typically the sharpest tools in the shed. Brilliant people tend not to need to resort to such petty crimes even if they do lack honesty.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 04:25:21 pm
content: Quote from: james_s on May 16, 2017, 04:11:00 pmIf they had brains they'd be bankers or lawyers.

author: drussell
author_rank: Super Contributor
timestamp: May 16, 2017, 04:37:48 pm
content: Quote from: RGB255_0_0 on May 15, 2017, 08:43:18 amYes they do... The way they work is to measure the current flowing in and out of the line and neutral (or line and line on a North American 240v circuit) using a balanced current transformer arrangement. Any significant current flowing (here usually about 5ma) in the circuit that does NOT return via the other wire must be flowing through something else outside the intended circuit one way or another, so it trips.It has nothing to do with the earth conductor. It doesn't measure the current on the ground wire, it measures thedifferencebetween the current in the two current-carrying conductors. Eg., if you somehow leak more than 5ma from your 2-wire hair drier to the sink faucet, it will trip.Am I misunderstanding your use of "mis-used"?

author: Seekonk
author_rank: Super Contributor
timestamp: May 16, 2017, 04:58:36 pm
content: When I bought my house I went in the basement a found a one foot section of water pipe suspended from a wire. In the middle there was a clamp that had a big yellow tag. It said in bold letters, Do not remove this wire or clamp. Always read and follow safety instructions.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 05:03:00 pm
content: Quote from: drussell on May 16, 2017, 04:37:48 pm

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 05:24:00 pm
content: http://www.dailymail.co.uk/news/article-3004108/Shocking-moment-passers-refused-help-fatally-injured-South-African-man-burst-flames-stealing-copper-wires-electricity-substation.html

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 16, 2017, 07:00:17 pm
content: As others have mentioned, those stealing power are often not in the top tier of intelligence.Those who steal copper generally make the power thieves look like geniuses.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 07:23:42 pm
content: Quote from: Gyro on May 15, 2017, 11:37:11 amActually you're right, it's not silly, it's plain outright stupid and adds unnecessary complexity to the installation and testing. Relying on a100% functioning ring circuit to carry 32A over 2.5mm2 wire is asking for trouble. Yes, but you have fuses in your plugs, bravo...As for sidetracking the "tread," it's mains wiring and switch related...

author: Nusa
author_rank: Super Contributor
timestamp: May 16, 2017, 07:34:53 pm
content: Quote from: RGB255_0_0 on May 16, 2017, 05:03:00 pmTwo things wrong with those videos.a) They didn't demonstrate that it was a working GFCI device with the test button on the outlet.b) In these days of plastic sinks and plastic drainage pipe, they were testing in ungrounded pools of water. Easiest electrical return path is still the neutral in the cord. Drape a wire from a grounded metal object into the water and I bet it trips immediately. Understand the wire is a stand-in for your body.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 07:39:52 pm
content: yup, without a ground path to the water, the water across the line and neutral is seen by the gfci as a normal load.

author: DBecker
author_rank: Frequent Contributor
timestamp: May 16, 2017, 07:40:49 pm
content: Quote from: Gyro on May 15, 2017, 11:37:11 amIt's actually on-point for the conversation: providing line voltage electrical advice is extremely region specific. Wiring that is normal in one region is unsafe and forbidden in others.Ring mains are common in the UK. That's where the electrical outlets (receptacles and fixtures) are wired in sequence, and both ends terminate at the electrical panel. Every outlet thus has two paths, and the conductors only need to be half the size.This wiring is forbidden in the U.S. Here the circuit must only be supplied from a single point, and the wiring may branch. Instead of a ring, it's a tree.A few minutes thought makes it clear how different these wiring systems are, and how dangerous it is to use experience with one system on the other.Disconnecting a wire in the U.S. system leaves everything 'downstream' unpowered, If you unscrew a wirenut, only one of the wires will be live. In a ring main system when you remove the connector (which won't be a wirenut), both sides will be live. A single broken connection in a ring main system leaves the outlets powered but dangerously unprotected. In the U.S. everything downstream will be unpowered. A tradesman electrician from one region will do exactly the wrong thing in the other.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 07:52:08 pm
content: Quote from: Nusa on May 16, 2017, 07:34:53 pmMike Holt has one but I cannot find it on its own. Yes it's on a GFCI. But that's what I'm saying by 2-wire.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:01:05 pm
content: Quote from: P90 on May 16, 2017, 07:23:42 pmIt was brought in to save copper from what I understand. Our wiring method was brought in during the 40s or 60s.

author: Gyro
author_rank: Super Contributor
timestamp: May 16, 2017, 08:06:35 pm
content: Actually it is based on the fact that all standard UK plugs are fused (max fuse rating 13A), thus limiting the maximum drain at any point on the ring main (26A for a dual socket). The fuse / breaker for the ring is rated at 30/32A.It's still not "silly".

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:08:12 pm
content: Quote from: Gyro on May 16, 2017, 08:06:35 pmI thought it was brought in because silver wire was changed to copper or my memory is scrambled.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:11:45 pm
content: Quote from: Gyro on May 16, 2017, 08:06:35 pmthat says it all... I rest my case...

author: Gyro
author_rank: Super Contributor
timestamp: May 16, 2017, 08:12:05 pm
content: We've never used silver.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:15:33 pm
content: I'm guessing he was implying aluminum (that's aloonimium to you) LOL

author: Gyro
author_rank: Super Contributor
timestamp: May 16, 2017, 08:19:04 pm
content: Quote from: P90 on May 16, 2017, 08:11:45 pmI suggest you go and search out the thread where this was last discussed to death. 2.5mm2 T&E cable is rated to carry 26A continuously. In practice no one is ever going to pull 13A on both outlets on a dual socket simultaniously. Even a 30A fuse is going to blow in a fault situation way before a 26A continuouly rated cable gets into trouble, even in the unlikely situation that the ring gets broken.

author: RGB255_0_0
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:23:47 pm
content: Quote from: P90 on May 16, 2017, 08:15:33 pmI may have been confusing it with telephone wiring. I'm sure I have read that we used silver and it was salvaged and changed for copper during the war years. Because we used copper during the war there was a shortage so we had to make efficient use of it, which led to ring mains. Memory is either confused or clouded or full of misinformation/Chinese whispers.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:23:58 pm
content: I wonder if my Land Rover has a ring main electrical?

author: Gyro
author_rank: Super Contributor
timestamp: May 16, 2017, 08:34:37 pm
content: Quote from: RGB255_0_0 on May 16, 2017, 08:23:47 pmEven at its peak the British Empire wasn't wealthy enough to wire its houses in Silver. You'd have had wiring thefts by Jewellers.Aluiminium was used for a time in the '50s (I think) due to a copper shortage.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 16, 2017, 08:37:47 pm
content: Quote from: Gyro on May 16, 2017, 08:19:04 pmYou beat me to a very similar observation.You don't need to pull 26A out of one socket though - it can be over any number on the same leg of a broken ring and, while 2.5mm2T+E cable is rated at 26A (the table I have actually says 27A), that is infree airyou have to de-rate it if it is enclosed at all - down to 13.5A if totally enclosed by insulation in a stud wall for example. It is not difficult to imagine that some installations might be dangerous if there was heavy load on a broken ring but not all, or even most by any means.The 13A fuse in the plug is there to protect the appliance cable, not the ring.Having done some wiring in France I think I now prefer individual circuits over rings. French "normes" specify up to 8 sockets per circuit with 2.5mm2cable, protected by a 20A dual pole breaker. Not too wild about the fact that officially the sockets are only rated at 16A so you could try to pull all 20A through a single socket however I suspect that would actually work OK in practice, but whether a typical appliance cord would pass 20A without becoming a fire risk I'm much less certain about.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 08:40:37 pm
content: many old homes in the US burned to the ground as a result of aluminum wiring...they even had copper clad aluminum, any way to save a buck...

author: Gyro
author_rank: Super Contributor
timestamp: May 16, 2017, 08:42:02 pm
content: Quote from: P90 on May 16, 2017, 08:23:58 pmWell if it's an original one, the chassis is effectively a welded square, does that count?Here's the last thread on ring mains (I think). Knock yourself outhttps://www.eevblog.com/forum/chat/safest-mains-plug/P.S.QuoteYes, it was a worldwide copper shortage, some references to it here...http://ecmweb.com/content/1950s-1950-1959

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 09:50:35 pm
content: Aluminum wire is still used in some applications, or was until recently. My 200A service entry is aluminum and the 50A circuit that formerly powered the electric stove in my kitchen before it was switched to gas is aluminum wire. The issue was not so much the aluminum wire, but aluminum joined to copper or brass terminals designed for copper wire and done so without the grease that prevents oxidation.

author: drussell
author_rank: Super Contributor
timestamp: May 16, 2017, 09:57:40 pm
content: Quote from: P90 on May 16, 2017, 07:39:52 pmYeah... Using a hairdrier as an immersion heater is pretty silly but it is a valid load to the GFCI until you touch the water with a path to ground or something.... At which point the GFCI will trip and you'll survive, likely with just a quick tingle. A standard outlet would light you up like a Christmas tree if you're well enough connected to ground.Therefore, I would say the GFCI protects you from a 2-wire load, even if "mis-used", though perhaps not quite as "thoroughly" as if the hairdrier had a grounded metal part, of course...

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 09:59:50 pm
content: Quote from: james_s on May 16, 2017, 09:50:35 pmyes, the issue is mostly with the 10 and 12AWG, not so much the larger feeds.Thermal expansion and contraction causes looseing of the screw terminals over time, oxidation of the aluminum occurs, causing high resistance, and eventually leads to arcing and worse fire.

author: Seekonk
author_rank: Super Contributor
timestamp: May 16, 2017, 10:12:28 pm
content: I had an apartment in the 80's wired with aluminum. I had to tighten half the connections just for the light loads of the wall outlets to work.

author: P90
author_rank: Frequent Contributor
timestamp: May 16, 2017, 10:33:15 pm
content: I know if I lived in the UK, I would rewire my house to eliminate that ring main...

author: Zero999
author_rank: Super Contributor
timestamp: May 16, 2017, 10:36:55 pm
content: Quote from: P90 on May 16, 2017, 10:33:15 pmYou'd only be allowed to do that, if you're part P certified.Anyway, what's wrong with the ring circuit? So far all you've done is say you think it's bad but haven't actually said why.

author: Macbeth
author_rank: Super Contributor
timestamp: May 16, 2017, 11:28:42 pm
content: Quote from: Hero999 on May 16, 2017, 10:36:55 pmNot forgetting you can attach a spur to any ring outlet. Also wiring wise the pair of cables just goes up/down vertically into the floorboards - there is no real installation cost, the copper being the expensive item.It is also not an actual ring of cable going horizontally around the house sockets (which I am ashamed I originally thought was how it was done!)

author: james_s
author_rank: Super Contributor
timestamp: May 16, 2017, 11:41:55 pm
content: While the concept of a ringmain is quite foreign to me I can't really think of anything genuinely wrong with it. A British friend and I have discussed this sort of thing extensively, I've been over there and helped him out with some wiring projects and he's been over here and done the same. We've identified minor advantages and disadvantages of our respective systems, hardware and methods but no clear winner. I can't say that either system is superior to the other, they're just different.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 12:09:23 am
content: Quote from: P90 on May 16, 2017, 07:23:42 pmring is not silly its stated in the code and very well known in certified community. what is silly and sidetracking is that you are using 2.5mm2 single core wire for your house wiring and blame the ring code because your house burn due to 32A. do you think the code is made by a bunch of fools?

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 12:50:38 am
content: Quote from: james_s on May 16, 2017, 11:41:55 pmthen you don't fully understand the way the ring main works. As mentioned already, if there is a break somewhere in the wiring or connections, it no longer provides adequate current capacity in the remaining undersized conductors. It's a system that should be done away with. and spurs just add to the mess. They're constantly coming up with a new way to test the ring main.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 12:55:49 am
content: ring is another option for cheaper cost. if you take the worst case scenario, nothing on this world can be saved from your argument.

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 01:21:24 am
content: Quote from: P90 on May 17, 2017, 12:50:38 amI understand it perfectly well. Have you got any evidence of the scenario you mention ever occurring and leading to a fire? Don't you suppose there's enough overhead that the wire will not burn up should a break occur and the full load pass through a single run of it? A broken ring would lead to excess voltage drop and wasted energy heating up the wire but I seriously doubt it would catch fire.I have on the other hand encountered multiple near fires with the US branch system. See attached, this was at a home of a relative, a faulty connection in the crappy spring loaded terminals of a cheap receptacle heated up due to the load of a space heater on the end of the run in the other bathroom. It's very fortunate that the wire burned off and broke the circuit before setting the wood paneling on fire. Had this been a ringmain there would have been a redundant path which would have prevented this bad connection from getting so hot that it oxidized and dropped even more voltage.A similar thing happened years ago in my grandmother's house, she went to plug in her coffee grinder and saw something glowing inside the receptacle, turned out the same issue had occurred, oxidized connection in the spring loaded terminal, caused excess resistance and the refrigerator on the end of the run was enough load to heat it up. Had she not happened to notice it and shut off the circuit that could have ended much, much worse. In my own house I had yet another backstab terminal on a cheap receptacle fail, I was fortunate in that the load was small and the end of the wire oxidized heavily enough that it opened the circuit rather than causing a big meltdown.Anyway the point is faults can and do occur and they can lead to serious consequences, I don't see a ringmain as being any more prone to faults than a branch configuration. The real fault here of course is cheap crappy receptacles. The spring loaded backstab terminals are horrible, I wish they would ban them. Instead in the US they have mandated a bandaid, requiring the use of arc-fault breakers on virtually everything. They cause frequent nuisance trips but the trade unions get to keep the quick to install push-in terminals they love.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 01:27:07 am
content: and using 2.5mm2 core wire is not in the code, not even close. the smallest wire meant for household radial connection is 3 cored/strand wire each core can happily take 10A, twice or triple that at some warmer temperature, which the circuit breaker will trip long before that. for larger demand, you can use more expensive 4 cored or 5 cored iirc. using 4 cored on 2 radials can be costly prohibitive esp in large building. so ring connection using 3 core can save some penny, and use thicker plastic armour (conduit) if you wish to lessen the possiblity of the worst (the black rats), plastic conduit is much much cheaper compared to copper, even the thicker one.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 01:27:54 am
content: Quote from: Mechatrommer on May 17, 2017, 01:27:07 amI have no idea what code or type of wire you're talking about but it makes little sense.

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 01:45:26 am
content: Quote from: james_s on May 17, 2017, 01:21:24 amThat's the fault of the shitty backstab devices, not the wiring. recent outlets don't allow for 12awg wire only 14awg, to eliminate backstab connections on 20amp circuits, regargless backstabing should not be allowed by code.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 01:55:38 am
content: Quote from: Monkeh on May 17, 2017, 01:27:54 ami guess you havent buy few house/residential electrical wiring in hardware store that is recommended by the electrician. i'm not expert in the field those wires are rated in ampere or some mystique number i dont appreciate at remembering that. those are solid strands sold in rolls, not the usual wire you found on the outlets or on the desk. i have made expansion to the house wiring/panel box etc and still have the stock somewhere so i know what the picture is. there is no 2.5mm2 wire around in the overhead ceiling, except on hobby desk for tinkering. i believe if you have those tiny cable up there, regulation should not be blamed if your house catches fire.here some reference...http://www.homedepot.com/c/factors_to_consider_when_wiring_your_home_HT_BG_ELhttps://www.thespruce.com/electrical-wire-gauge-ampacity-1152864this are proper wire... not the 2.5mm2 area. and they are not cheap esp if the length measures in km..

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 02:03:00 am
content: Quote from: Mechatrommer on May 17, 2017, 01:55:38 amYou have absolutely no clue what you're talking about.2.5mm² is a fair size conductor and it does not make houses burn down.QuoteHere are some random links and a picture of an unknown size of multi-conductor solid core wire. Thanks for that.Please come back when you can adequately describe types of wire and conductor sizes.

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 02:15:19 am
content: I feel I'm in The Twilight Zone

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 02:16:11 am
content: Quote from: Mechatrommer on May 17, 2017, 02:07:06 amWhy would I read some random page from a US DIY store about wire types which aren't relevant to me?Approximately 1.8mm diameter off the top of my head. See, unlike you I know what wire is and how to specify it.Why don't you specify what these random wires you use are, and explain why you use them. It'll be a good exercise for you. While you're at it, explain why each and every conductor in my house is inappropriate and will cause my house to burn down, despite being appropriately sized and installed according to the regulations at the time. Yes, that includes the 2.5mm² in the ring finals (there are three of those, amazingly, none of them have caught fire yet).

author: DBecker
author_rank: Frequent Contributor
timestamp: May 17, 2017, 02:22:23 am
content: Quote from: Hero999 on May 16, 2017, 10:36:55 pmThe problem is not in operation, where it can potentially save copper, but in failure. If one connection fails, all of the current flows on only one segment of the ring rather than on both paths. There isn't any indication of a problem, so the fault can persist until it causes a fire.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 02:32:55 am
content: Quote from: DBecker on May 17, 2017, 02:22:23 amThis is indeed the flaw. On the upside: Fire does not generally occur, due to the conductor size (it takes an extreme combination to cause this), and open rings aren't all that common except when tampered with, as in general our wiring is fairly robust. There are no wire nuts or stupidly low quality push-in contacts (Which are a great invention: The ones on your sockets just suck.) to be found.As an added bonus: We have testing over here!

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 02:37:54 am
content: How does it cause a fire? I'll ask again, has anyone ever seen an incidence of it causing a fire? Has anyone calculated the maximum temperature rise of a single run of wire up to the trip current of the breakers used? I don't think you have, and I don't think anyone who is saying they're dangerous has ever even touched one. It reminds me of the British guy I once saw ranting about how terrible and dangerous the wire nuts common in the US are. He thought they were just a plastic cap, had absolutely no clue that they have a metal insert that bites into the wire, had no idea how secure of a connection they actually form, he had never even used one and yet was ranting that they're dangerous. That's exactly what I see a few people here doing regarding ringmains.Yes the faults I mentioned are the fault of shitty backstab connections, just like the proposed ringmain problems are the fault of hypothetical shitty connections, what's your point? Bad connections cause fires, whether ring or branch there are potential advantages and disadvantages, that still doesn't mean one or the other is inherently safer or superior.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 02:42:21 am
content: Quote from: james_s on May 17, 2017, 02:37:54 amI haven't lately, but the people who wrote the regulations certainly have.QuoteI am very much not a fan of wirenuts. They're not adequately reusable, they stress the conductor, they make visual inspection of the joint difficult to impossible, and you should destroy the used length of conductor if you remove one and rejoint. There are far better alternatives up to and including the simple screw terminal.Oh, and I have I mentioned it's very easy to inadequately install them? Yeah, not a fan.. They were, once upon a very long time ago, briefly used here. They did not last. Some really, really cheap sellers have brought them back, never seen anyone dare to use them.

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 02:55:42 am
content: I'm referring to the people saying that ringmains are dangerous when I ask about temperature rise calculations, not the people who actually have or have worked with them.Wire nuts have been standard for many decades here, trust me, they work very well. It's not difficult to install them properly, the good ones are reusable if necessary and if installed properly they don't damage the wire. Visual inspection is possible by looking up from the bottom, the bare copper should just be visible as it goes into the spring insert and the insulation should stop at the same level on all wires. Proper installation is not difficult, just like any electrical work there is a technique to it but that's why people who don't know how to do it properly are supposed to hire an electrician. They're actually very reliable and less likely than screw terminals to loosen up. Again I can't say there's a clear winner between the two but the wire nuts we have here work very well. You just don't see problems with them in general, they just work. If you were to pull on the wire hard enough in most cases the wire would break somewhere else before the wire nut would fail. Note that the type available over there may be different, if you've had the problems you describe then I suspect they are.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 02:57:58 am
content: Oh, I've never used any of the ones sold over here. Over there, I have used maybe a half dozen different examples, ranging from the terrifyingly bad to the merely "I'd rather not". I'll still take my screw terminals. Or, preferably, a nice Wago. Yet to have an issue with those.

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 03:06:18 am
content: I mostly use Ideal branded wingnuts, in ~25 years going through hundreds of them, wired a couple of houses and countless workshops, sheds and small projects, I don't recall a single problem with one. The knockoffs are not very good, and I don't particularly care for the 3M wire nuts from the 1960s, those are somewhat rubbery which hardens with age, I don't like to reuse those. There's absolutely nothing wrong with wire nuts.

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 04:12:33 am
content: wirenuts are a terrible device, and i've seen plenty of so called professional electricians install wirenuts incorrectly which is easy to do. wirenuts fatigue the wire and often times allow a conductor to be missed partially. most common electrical problems I've seen have been at a backstabbed outlet or a loose wirenut which is hard to detect when installing. Just because wirenuts have been used for many years doesn't make them a good choice. European barrier strips are better, and one can visually see if a connection is properly made while installing. Also reusing wire after removing is a mess, like when trying to add onto an existing connection during renovation. Wirenuts are a shitty solution to making a solid reliable connection, thats why the rest of the world doesn't use them.

author: Electro Detective
author_rank: Super Contributor
timestamp: May 17, 2017, 04:28:51 am
content: I've tried to love wire nuts but they are a ball breakerthe worst being the case where you are 'twisting' it home and the plastic is not gripping or slipping on the metal insert.or if there are 3 smaller wires going in, you can't visually inspect if all three have equal 'meat' going into the twist zone.If a plastic cap fails at a future date and some DIYer sticks his hands in, OUCH !Screw down terminals gets my vote, thank you

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 04:58:43 am
content: Quote from: Monkeh on May 17, 2017, 02:03:00 amright i was at work and confusing wire radius and diameter. but when a troll saying 2.5mm2 (14AWG 35A chassis current rated wirehttps://www.tedpella.com/company_html/wire-gauge-vs-dia.htmand 15A household current rating) cannot take 32A, you are on rush hour and bad internet connection, you'll (not you) start generating gases out of your ear (brainfart). if any, there will be slight temp rise far from melting the rubber sheath, let alone to burn a house. there is another solution which is using 2 16A breakers at both end of the ring, if one is to even use a cheapskate smaller than 2.5mm2 rated wire so damage due to 32A is out of question. and if one is to really use the full capacity of 7KW device, then he should be rethinking of his home's life. instead of relying on the approved 15A wire. wiring alone is not only the one point of failure.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 05:15:46 am
content: Quote from: Mechatrommer on May 17, 2017, 04:58:43 am2.5mm² is larger than 14AWG, and neither is rated for 35A in any regular installation. And 15A's amusingly low!QuoteUsing two breakers is A: Dumb, and B: Not compliant. Same goes for using any wire other than 2.5mm².

author: RukyCon
author_rank: Contributor
timestamp: May 17, 2017, 05:18:11 am
content: I really don't have a problem with wire caps but i don't like to reuse them too often because the spring could be corroded or it could have no spring at all.Though thinking about the no spring one it would not stay on if it had no spring.

author: Unknown
author_rank: Unknown
timestamp: May 17, 2017, 05:19:19 am
content: Quote from: james_s on May 17, 2017, 01:21:24 amI absolutely loathe those "builder grade" stab-only plugs. When I see them they're usually falling apart with chunks of plastic missing, and are barely able to hold the prongs of a plug anymore.I went through a few years ago and ripped out all the ones in my house and replaced them withLeviton "Industrial Grade" receptacles. Also the similarly cheesy light switches were chucked and replace with the similarly ruggedLeviton "Industrial Grade" 277 volt versions. Ugly plastic cover plates were all replaced with brushed stainless steel. Not that expensive all things considered, and I will probably never need to replace them again.Industrial or Hospital grade is the way to go for receptacles. A night and day difference; now it actually takes force to remove plugs, they don't just fall out under their own weight.Also, it hardly takes more than a few seconds to properly terminate wires with screw terminals. How lazy can you get? I suppose stabs really aren't out of character though, given the overall shoddy, minimum effort level of work you see in residential electric.

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 05:23:30 am
content: Quote from: Monkeh on May 17, 2017, 05:15:46 amas you seems to be the top notch engineer around here based on your "intelligent and informative" posts, maybe you can start elaborating why is that so.https://www.alibaba.com/product-detail/Kenya-Hot-selling-PVC-insulation-Copper_60472362866.html

author: DBecker
author_rank: Frequent Contributor
timestamp: May 17, 2017, 05:24:32 am
content: Quote from: Monkeh on May 17, 2017, 02:57:58 amI dislike being involved with meandering threads, but somehow that isn't stopping me.By 'Wago' I'm assuming you mean a specific spring clip connector, rather than the higher end stuff they make.I find them appealing, compact, convenient, error-resistant, and easy to inspect. But I can see they are not necessarily a better connector. The contact points are small and concentrated. One side bites into the wire at almost a single point. The other side might make a longer contact, but it's not certain to and the contact area is small.In contrast a wire nut is used with twisted-together wires that deform to have a large contact area. The helical steel spring inside forms threads into the wire at multiple points for high retention strength and the multiple wraps of the spring results in a high contact force. If the connection is made correctly, it is stronger and lower resistance. (The 'if' part is a big weakness.)

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 05:25:49 am
content: I always use spec grade receptacles myself, usually Pass & Seymore because that's what the local shop stocks. For switches the cheap ones seem to work ok but with receptacles it definitely makes a difference.Doesn't take long to use the screw terminals but does take longer than just poking the wires in the holes and it adds up if you're building houses and installing hundreds of them.

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 05:33:36 am
content: Quote from: Elf on May 17, 2017, 05:19:19 amUnfortunately, from what I've seen, that shoddy, minimum effort level work isn't only associated with electrical, rather all aspects of new construction...

author: P90
author_rank: Frequent Contributor
timestamp: May 17, 2017, 05:36:52 am
content: I always buy the spec grade outlets, the cheap $1.19 ones fall apart before you get to the job to install them, they are plastic welded halves, the spec grade have more metal and better contacts, plus the screw connections are poke and screw like gfci outlets.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 05:37:19 am
content: Quote from: DBecker on May 17, 2017, 05:24:32 amI mean their installation connectors in general. I've used most types - full size and compact push-in (773 and 2273 series), lever action (222 and 221 series), and the lighting connectors (I want to say 224 series, I have none on hand). Also various older types and clones thereof (tend to avoid those).QuoteThe contact points are more than adequate for the size of conductor they are rated for. Only one side is a current-carrying contact, the other is merely the spring load.QuoteAnd also unwanted deformation of the wires, work hardening, and stretching. There's no need for a lower contact resistance as it's already less than the resistance of the stripped wire you insert.Quote from: Mechatrommer on May 17, 2017, 05:23:30 amErr.. why what is so, and why am I looking at a cheap, untrustworthy source of wire?

author: Unknown
author_rank: Unknown
timestamp: May 17, 2017, 06:09:33 am
content: Quote from: james_s on May 17, 2017, 05:25:49 amP&S are pretty decent. With switches I suppose I've never seen an electrical problem with the cheap ones for lighting, but the tactile aspects of the industrial ones are nice. A nice solid thunk every time you flip it and a strong spring bias to either position.Quote from: james_s on May 17, 2017, 05:25:49 amRight. It just irks me though, I can't imagine what could possibly be less effort. Maybe stabs with some sort of insulation displacement so you don't even have to strip the wire? Self adhesive faceplates with no screw? Probably some patentable ideas there if you could convince the NFPA. I suppose it offends me because I actually take pride in the things I do and care about the end result.Quote from: P90 on May 17, 2017, 05:33:36 amYes, I think that is sadly the case. Although I do see decent commercial construction a lot more often than residential construction.Of course, my personal aesthetic is biased towards commercial. This is in my utility room downstairs:

author: mfratus2001
author_rank: Contributor
timestamp: May 17, 2017, 04:12:07 pm
content: Perhaps I missed it, (I did miss one in the first comment) but I did not see any references to anything... if this site is for learning, post some links!https://www.electriciancourses4u.co.uk/useful-resources/history-of-wiring-colours-cable-sheathing-bs7671/http://wiki.diyfaq.org.uk/index.php?title=House_Wiring_for_BeginnersFirst of all, I had no idea that wiring in England was so complex. I suppose it has to be, with the high voltage involved.In comparison, USA wiring is so simple, and so consistent.We don't have zones, but I think all USA regulations now require GFI (RCD in England) outlets in bathrooms and kitchens/laundry rooms.We have three wires in the USA - Hot, Neutral, and Ground. The ground wire is now as large as the other wires, because the last thing you want is for your ground wire to burn up. If there is a short to ground, you want the breaker to blow, not a fire. Hot and Neutral are the current-carrying wires, and Ground is for safety. Neutral connects to Ground at the breaker box. Neutral is never switched in modern wiring, although I have seen that in some older overhead light installations.

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2017, 04:42:04 pm
content: QuoteStrange how people on different sides of the pond can sometimes have such difficulty in following what those on the other side find so straightforward. To me, for instance, having to wire 240V circuits for high drain appliances and 120V for everything else seems complicated. UK /European wiring is all at the same voltage - and no specific added "high voltage" complexity related to it.QuoteExactly the same here (in terms of three wires etc). There are different grounding systems at the building supply entry point, but I think there are in the US too*. No we don't switch neutral in domestic systems either.*EDIT: As indeed there are around the world, Ref:https://en.wikipedia.org/wiki/Earthing_system

author: madires
author_rank: Super Contributor
timestamp: May 17, 2017, 05:02:34 pm
content: Quote from: Gyro on May 17, 2017, 04:42:04 pmI think, it's simply what you're used to. BTW, we got 3-phase systems adding some complexity

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2017, 05:22:48 pm
content: I was trying not to go there!At least they're not typically domestic.

author: madires
author_rank: Super Contributor
timestamp: May 17, 2017, 05:43:23 pm
content: In Germany usually any household get's 3-phase into the distribution box. You won't find IEC sockets, but the kitchen has a dedicated 3-phase junction box for the stove/oven, often also used to power a dish washer. Some home owners install an IEC socket for heavy machinery in their work shop or hobby room.

author: grumpydoc
author_rank: Super Contributor
timestamp: May 17, 2017, 05:53:13 pm
content: Quote from: madires on May 17, 2017, 05:43:23 pmIn France it's 3 phase once you go above 15kVA

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2017, 06:00:14 pm
content: In a domestic property the UK you only get 3 phase if you ask (and pay through the nose!) for it. The only time you'd typically get it in a house is if you are setting up a workshop with heavy duty machine tools.P.S.Quote from: madires on May 17, 2017, 05:43:23 pmHow many dishes do you guys wash???

author: BradC
author_rank: Super Contributor
timestamp: May 17, 2017, 06:05:05 pm
content: Quote from: Gyro on May 17, 2017, 06:00:14 pmThey're pretty common here too. Every house I've ever lived in (7 of 'em) had 3-phase.

author: Zero999
author_rank: Super Contributor
timestamp: May 17, 2017, 06:16:47 pm
content: Quote from: DBecker on May 17, 2017, 02:22:23 am1) I've never heard about a fire, due to that kind of failure.2) Any installation can be dangerous if one connection fails, such as the earth connection.3) One of the advantages of a ring main is if one earth connection breaks, there's still another earth connection to keep things safe.

author: CatalinaWOW
author_rank: Super Contributor
timestamp: May 17, 2017, 06:20:41 pm
content: Here in the US three phase is not generally available and is an extra cost option for domestic users.The extra cost depends on your situation. I am in a fairly rural area, and the high voltage distribution is single phase. There is a three phase line running along a highway a little more than a kilometer from me, so I am closer than many others in my area. But the cost of adding a kilometer + branch of the three phase system is more than I am interested in. If I ever develop a compelling need for three phase I'll install a rotary converter or the like.

author: madires
author_rank: Super Contributor
timestamp: May 17, 2017, 06:34:06 pm
content: Quote from: Gyro on May 17, 2017, 06:00:14 pmThe dish washer is connected in parallel with the stove, but just single phase. You never have enough wall sockets

author: Mechatrommer
author_rank: Super Contributor
timestamp: May 17, 2017, 06:55:45 pm
content: dish washer uses electricity meh? we use the hands... our 1KW induction cooker + smoke exhaust fan over there is mainly for decoration, albeit ring sockets are provided specially for them. btw our much complicated 3 phase only goes to commercial premises. higher rate, higher rate $$$ ... i guess we need special order delivery if we want it to residential place.

author: SeanB
author_rank: Super Contributor
timestamp: May 17, 2017, 07:04:37 pm
content: Germany 3 phase because you can use 4 wires of small diameter for the supply, and the load is going to be balanced down the street line, so you can use a smaller diameter neutral, as the current it has to handle is only the imbalance between phases, not the full phase current. Thus a lower cost of copper per house supply for the same power level, plus your distribution system has a large copper saving in smaller neutrals. the inherent balancing of load is also good for the supply side, less draw on one phase with peak cooling time is balanced down the street, and all loads are not on a single phase.UK uses ring mains, because of history, and they will not change, though the wire sizes have changed over the decades as cable insulation improved, the original cables used DCC gutta percha tinned copper, and a ring main would have been a 4mm cable, but the high temperature rise allowed on new PVC insulation means the cable size was relaxed to 2.5mm later on.The silver wire was used in the Manhattan Project, as they needed massive electromagnets in the early isotope separators, and copper was a war resource and scarce, so the US Mint loaned them hundreds of tons of silver, which was used to make wire used to wind them. Slight power saving as it had lower resistance, and after the war the silver was returned ( which is why none ended up as museum pieces) with only a small loss from all the processing and recovery.Wire nuts here in South Africa are not a plastic nut, but a ceramic unit with a thread formed in the inside, so you can twist the wire into them, and even in a fire they will not melt before the wire, even if they arc the cable melts first. Pretty reliable if applied right, like any other connector, and as before, differs per country. All sockets here and switches are not allowed to be push in, you have to have a screwed clamp on the wire, though the Wago style is becoming popular for joining cables in the junctions. Preferred though is a crimped ferrule and an insulating sleeve over it, used mostly on larger cables 4mm and higher, as that is the only method allowed other than a screw connector.Copper coated aluminium is very common, often used in windings of transformers, because it is cheaper, even if it has issues with creep and low melting point inside windings. If you have a newer microwave, new home appliance with an electric motor or any mains frequency chokes or transformers it is likely to be wound with CCA wire. A lot of the cheap premade cables are also that, or even copper coated ( hopefully) steel, or even some mystery wire of indeterminate type, most likely made from poor grade recycled metal. Buy a cheap set of jump leads and they are almost sure to be a CCA core in a very thick foamed plastic cover, so that they look like high capacity, but which are not even going to pass 10A without overheating.

author: Gyro
author_rank: Super Contributor
timestamp: May 17, 2017, 07:15:54 pm
content: QuoteI don't think so on that one actually - our old 15A round-pin sockets used to be on radial circuits, obviously back in the '20-'30s there weren't very many of them. The ring circuit came in at the same time as the 'modern' 13A square pin (fused plug) sockets iirc.Edit: There would also have been lower rated radial circuits for the smaller 5A round-pin sockets for lamps etc. The whole thing changed to a common ring circuit when it became posible to limit fault load on appliance flexes due to the range of available fuse sizes in the 13A plug.https://en.wikipedia.org/wiki/AC_power_plugs_and_sockets:_British_and_related_types#BS_1363_three-pin_.28rectangular.29_plugs_and_sockets

author: IanB
author_rank: Super Contributor
timestamp: May 17, 2017, 08:44:24 pm
content: Quote from: CatalinaWOW on May 17, 2017, 06:20:41 pmThe difference in the UK is that the high voltage distribution to anything other than a single isolated house in the middle of nowhere is invariably three phase. The supply is stepped down through a three phase transformer to give a three phase low voltage supply, and the three phases are then distributed evenly between the houses fed by that transformer, one phase to any given house.This means that most houses do have a three phase distribution cable outside in the street and a three phase supply could theoretically be provided into the house. The snag is that having more than phase present exposes the line voltage of 415 V in the supply cabinet. Electricians are usually prepared to do hot work on 240 V systems, but I think not so much on 415 V systems. (Also since the substation transformer is often large enough to supply dozens of houses the fault current capability is substantial.)

author: nali
author_rank: Frequent Contributor
timestamp: May 17, 2017, 08:58:51 pm
content: Quote from: IanB on May 17, 2017, 08:44:24 pmOddly enough, the house where I lived as a kid had 3 phases into the house. Only one of them supplied the meter the other two had no fuse or tails and were "protected" only by the crimped wire seal. I can't remember the age of the house, something like 1910-1930 IIRC.

author: Zero999
author_rank: Super Contributor
timestamp: May 17, 2017, 10:09:31 pm
content: Quote from: IanB on May 17, 2017, 08:44:24 pmYes and because the fault current is so high, each house has a large, high breaking capacity fuse (normally 100A but it probably depends on the size of the property) where the cable enters the property, before the meter.

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 10:12:08 pm
content: In the US you don't see fuses before the meter in residential situations, normally the primary of the distribution transformer on the pole or in a vault will be fused but otherwise the first protection device is the main breaker in the panel. 200A 240V service is typically standard these days though large houses may have 400A and very large houses (as in mcmansions) may have 600A service.

author: Monkeh
author_rank: Super Contributor
timestamp: May 17, 2017, 11:23:26 pm
content: Quote from: mfratus2001 on May 17, 2017, 04:12:07 pmThis is entirely unnecessary, as the current required to make the conductor fail is many times greater than the current required to open the breaker either magnetically or thermally. The greater risk (as seen by our regulations, at least) is raised ground voltage during a fault leading to shock risk. This is managed by ensuring the voltage cannot raise sufficiently high to be dangerous or ensuring immediate disconnection rather than waiting for a thermal trip (using an RCD(GFCI)).E: And I should mention that trip times of breakers are verified by measurement of the circuit, as opposed to "She'll be right".Quote from: james_s on May 17, 2017, 10:12:08 pmIn the UK you don't see transformers catching fire much.

author: james_s
author_rank: Super Contributor
timestamp: May 17, 2017, 11:45:36 pm
content: I don't think transformers catching fire is common anywhere. I've seen it once, when the substation next to my middle school received a direct lightning strike. The transformers are fused at the primary to protect against a fault on the secondary. Not common, but neither is a fault that trips the main breaker in a house, you still need to have protection.

author: Macbeth
author_rank: Super Contributor
timestamp: May 18, 2017, 12:41:25 am
content: I wrote a post of the pavements with underground transformer outside local shops going up in flames but realised my post was referring to a certain community and so had to delete it.Obviously the transformer went up in flames because it wasn't engineered correctly. Nothing to do with the people running the local shops who had to suffer loss of business and other stuff when it went up.

author: RukyCon
author_rank: Contributor
timestamp: May 18, 2017, 09:40:42 am
content: Side question:I built a custom fixture less than a year ago and i'm wondering if it's a good idea to ground the two metal boxes that cover the ballasts.

author: madires
author_rank: Super Contributor
timestamp: May 18, 2017, 09:53:47 am
content: Quote from: james_s on May 17, 2017, 10:12:08 pmStandard setup in Germany: The power cable goes into the house connection box, which got fuses (3-phase, NH fuses, usually 35 or 63A for a small house with one or two flats). Next step is the main distribution panel with power meters and NH fuses (typically 25 or 35A) for each flat. Each flat or floor has its local distribution box with RCDs, breakers on so on. The main distribution box might house the RCDs and breakers for the cellar. Old homes might have just the house connection box and the main distribution panel.

author: Monkeh
author_rank: Super Contributor
timestamp: May 18, 2017, 01:47:16 pm
content: Quote from: RukyCon on May 18, 2017, 09:40:42 amIf they contain a typical single-insulated ballast and single-insulated wiring, well, yes.

author: Gyro
author_rank: Super Contributor
timestamp: May 18, 2017, 01:53:18 pm
content: Quote from: madires on May 18, 2017, 09:53:47 amPah! You can still wash more dishes than usA typical house incoming supply fuse in the UK is around 80A, single phase.