How To Identify Wires? - Page 1
Forum section: electronics / beginners

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 07, 2011, 07:24:51 pm
content: I want to attach this plug:.. to this cable which consists of 3 wires:So i can use this splitter:Questions:1.How do i knowwhich wire is which? I am in Israel.2.I saw such plug which cost 5 times less. I asked dealer what is the difference and he said quality. Was it item's quality or just dealer's speculation?Thank you.

author: SgtRock
author_rank: Unknown
timestamp: November 07, 2011, 07:34:08 pm
content: Dear Boris_yo:--It is the darndest thing. I still cannot see your pictures or the links to them. Duh!"The telegraph is a kind of a very long cat. You pull his tail in New York and his head is meowing in Los Angeles. Radio operates the same way, except there is no cat."Albert Einstein 1879-1936Best RegardsClear Ether

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: November 07, 2011, 07:34:45 pm
content: Blue is NeutralBrown is Live (Line)Yellow/green is earth (ground)

author: metalphreak
author_rank: Frequent Contributor
timestamp: November 07, 2011, 07:41:03 pm
content: http://www.yegpowercords.co.uk/PDF/EL212.pdfhttp://www.qualtekusa.com/Catalog/Power_Cords/PDF%20Files/39800201.pdfLooking at the plug with the pins facing you, left pin is Live, right pin is Neutral, and the bottom pin is Ground.Wire colours are as mike statedSgtRock: doeswww.imgur.comload for you? That's where they are hosted.

author: Unknown
author_rank: Unknown
timestamp: November 07, 2011, 09:17:12 pm
content: Quote from: metalphreak on November 07, 2011, 07:41:03 pmWas going to suggest that's the opposite of most countries then I remembered Hebrew is always written right to left.Would be a good idea for the OP to have his work checked although I'm sure he can manage just fine.

author: metalphreak
author_rank: Frequent Contributor
timestamp: November 07, 2011, 09:53:56 pm
content: If he has any IEC cables (computer/kettle etc type) he can use a multimeter to find which pin is what. IEC pinout is universal and I can find many proper specs for those

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 07, 2011, 10:29:56 pm
content: Quote from: metalphreak on November 07, 2011, 09:53:56 pmHow can multimeter show me which wire is which?

author: SgtRock
author_rank: Unknown
timestamp: November 07, 2011, 10:44:32 pm
content: Dear Metalphreak:--Thanks for the help. Yes, I load the page alright. I can see a box underneath upload images and no box under view images. I get the "hand" when I point at the box or any of the links in blue.--By the way, does Uncle Vernon have you on ignore. Because, he has me on ignore, and almost every time somebody quotes me, he jumps in an says something like:"It stole my precious, we hates it for ever and ever" only with more profanity. Thanks again for the help.Dear Boris_yo:I am glad our courteous and intelligent staff was able to help you. They are all in all a very good bunch."I could see that, if not actually disgruntled, he was far from being gruntled."P. G. Wodehouse 1881 1975Best RegardsClear Ether

author: IanB
author_rank: Super Contributor
timestamp: November 07, 2011, 11:15:26 pm
content: Quote from: Boris_yo on November 07, 2011, 10:29:56 pmYou find an existing IEC cable from some piece of equipment and disconnect it from all power sources. Your IEC cable should have an IEC connector on one end of it and a local mains plug on the other end. Then you look up the standard pinout for an IEC connector on the Internet, so that you know which of the three terminals is live, neutral and earth. Having done that, you use the continuity mode of your multimeter to see which terminal of the IEC connector is connected to which pin of the mains plug on the other end.

author: Jimmy
author_rank: Regular Contributor
timestamp: November 07, 2011, 11:24:54 pm
content: Plug the plug into the splitter/power-board then with a multimeter on continuity/resistance test. Test between the wire and the terminal of the pin on the plug. Then wire it to the matching ones

author: Jon Chandler
author_rank: Frequent Contributor
timestamp: November 07, 2011, 11:29:05 pm
content: Quote from: Jimmy on November 07, 2011, 11:24:54 pmExactly! This is what matters because you don't know if they followed the color convention in the strip. Presumably they did, but this way you don't have to find a reference for the color codes.

author: IanB
author_rank: Super Contributor
timestamp: November 07, 2011, 11:51:44 pm
content: Quote from: Jimmy on November 07, 2011, 11:24:54 pmI must have missed this option because it was too obvious. That's my excuse anyway...

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 08, 2011, 07:33:12 am
content: Thanks guys and to my multimeter i have done it as you can see below.Tell me if it is correct please, because now i question myself why another power extender wire that is connected to microwave combi-oven was configured differently when my relative attached plug to it. Please see picture below:He said that if to switch wrongly neutral and live, the switch will jump, but did he make mistake? And why all this time we had no problems with microwave combi-oven operating correctly and no switch jumps?Thanks!

author: Unknown
author_rank: Unknown
timestamp: November 08, 2011, 07:46:20 am
content: 99% of the time a crossed extension cord will work fine, for the other 1% it can be extremely dangerous. This cord should be repaired measure with the meter the same way that the plug top polarity was confirmed. Breaking a Neutral will switch off a device but it will leave the majority of the device still at mains potential.Would be a good time to ensure the outer cable sheath was properly clamped too.

author: IanB
author_rank: Super Contributor
timestamp: November 08, 2011, 08:18:47 am
content: With the socket in its normal orientation as you have pictured it, the live contact is on the right and the neutral on the left. Therefore the power strip you have just attached the plug to is wired correctly.It would then appear that the other extension cord is wired incorrectly. This may not cause any immediate problems, but it is certainly unsafe. Also, as Uncle Vernon pointed out, the cable sheath should be properly secured and not hanging loose.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 08, 2011, 09:03:06 am
content: Quote from: IanB on November 08, 2011, 08:18:47 amYou mean when wired correctly if i touch either neutral or live both separately, i won't get shocked unless i touch them both, but if wired incorrecty and both switched on each other's places, i would get shocked even by touching one of them or only live?Also mentioned to secure cable sheath. Where is it? The one that has brown, blue and green inner wires open? If yes, all of them are sheathed so i don't know what to be affraid of.

author: metalphreak
author_rank: Frequent Contributor
timestamp: November 08, 2011, 09:43:16 am
content: Sheath is the outer layer which covers all 3 wires.Touching neutral won't normally give you a shock as its normally tied to ground in the distribution grid (but not at your house). At my house its only about ~2V above local ground potential. This might not always be the case though so I do not advise trying it for funIf you touch the live wire you will most definitely get a shock as you form a potential difference of 110-240V between live and ground (your feet touching the floor!)

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 08, 2011, 10:04:29 am
content: Quote from: metalphreak on November 08, 2011, 09:43:16 amThat is only in case of incorrect neutral and live wires switching, correct?

author: Unknown
author_rank: Unknown
timestamp: November 08, 2011, 10:09:57 am
content: Quote from: metalphreak on November 08, 2011, 09:43:16 amIf it is not it should be, while not all countries use such a strategy Australia has for many years had an MEN earth strategy. The neutral earthed at each premises.The exact rules for Australia can be found within AS:3000 but here's the FAQ.http://www.wiringrules.standards.org.au/LinkClick.aspx?fileticket=0dh1qsn5NBA%3D&tabid=380As for neutrals being safe to touch. No they aren't well they aren't when they aren't actually at neutral potential. A neutral break in the street feeder and that safe back strip will throw you out of the switchboard if touched. Likewise a black wire disconnected from the Neutral with a load still attached soon becomes an active. Mix that with bodged leads like our poster shows above and your in trouble again.Anyone who works with distributed systems knows it's not uncommon to have 50V+ differential between neutrals on differing floors of some older high rise buildings, particularly some of those using MIMS distribution feeders.Your quite correct that true neutral should have no potential to earth but neutral wires should be given the same caution and respect you give any mains cable.

author: Unknown
author_rank: Unknown
timestamp: November 08, 2011, 10:12:20 am
content: Quote from: Boris_yo on November 08, 2011, 10:04:29 amNo you touch anything with a potential to earth and you risk electrocution, electricityjust wants a path to earth and it care little about wiring order or insulation colour.

author: IanB
author_rank: Super Contributor
timestamp: November 08, 2011, 03:20:51 pm
content: Quote from: Boris_yo on November 08, 2011, 09:03:06 amNo, I don't mean any of that. I just mean that if you wire a plug or socket up wrongly it is unsafe (meaning that if some types of equipment fault occur you won't be protected as well as you should be).QuoteJust look at the socket hanging loose off the end of the extension cord with the coloured wires exposed. Isn't it obvious to you that it is wrong?

author: metalphreak
author_rank: Frequent Contributor
timestamp: November 08, 2011, 03:25:21 pm
content: I just assumed MEN systems just connected neutral to earth at the street transformer level, but doing so just before the meter box makes sense. The earth and neutral wires inside your home are separated though so the RCD systems can work. Speaking of which, don't always assume they will save you especially if they haven't been checked in a while. We had some work done on our house recently and the electrician found one of our RCDs was taking 3 times longer to trip than the minimum standard. When he replaced it, it kept tripping as we had a small neutral to earth current leak on a lighting circuit...As IandB said, if it is wired wrong, most (all?) devices will still work fine as its AC voltage. The problem is when there are fault conditions. Fuses are usually put on the live conductor, so when a fuse blows it completely disconnects the device. If the wires are switched, The fuse simply disconnects the neutral, and the device is still energised/hot. If the fault condition includes an internal short then the entire device casing could become live (which a fuse or other protective systems is supposed to prevent).

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 08, 2011, 04:35:58 pm
content: Quote from: IanB on November 08, 2011, 03:20:51 pmYes it does look wrong to me, but what could happen? The wires could become bent and after some time get cracks in them which would expose them?Quote from: metalphreakSo that would come down to microwave casing become live or computer chassis become live?

author: david77
author_rank: Frequent Contributor
timestamp: November 08, 2011, 04:46:17 pm
content: Quote from: Boris_yo on November 08, 2011, 04:35:58 pmThat might happen, what is more important though is the missing strain relief and the missing double insulation.It could easily happen that a tug on the cable might disconnect the PE (green/yellow) wire from the socket wich could turnappliances plugged into it into deadly time bombs. Their metal cases could give you a nasty shock, if an internal error appears the case could even be at full live potential.I don't know about rules in other countries, here in Germany the rule is to leave the PE wire in plugs and trailing sockets at least 5mm longer than the L and N wire. This makes sure that the last connection to break is the PE connection, should the cable be ripped violently out of the plug/socket.

author: Boris_yo
author_rank: Frequent Contributor
timestamp: November 08, 2011, 07:16:25 pm
content: So i should cut these long unsheathed wires until the point where there is 1.5cm left of them so they can fully get into plug and not left even 1mm of them outside?

author: Unknown
author_rank: Unknown
timestamp: November 08, 2011, 08:13:13 pm
content: Quote from: metalphreak on November 08, 2011, 03:25:21 pmIt's not something everyone Will encounter day to day more one for the electricians. But an understanding of what is going on never hurts.Quotetoo true and it's not just faulty RCDs, any RCD is only as good as it's points of reference, soggy earths and neutrals place havoc with their effective trip points. While I'm a real fan of RCDs (legislated or optional) I'll be the first recommend they not be assumed to provide absolute safety.In our crazy over legislated "protect us from thy selves" environment RCDs are mandatory for all GPOs in new works. At the same time, type approval is being given to no name 3KA rated devices of dubious origin which may or may not have undergone any form of compliance testing our side of the pond. You can guess what is being used in many shiny fronted developer build structures so I'll always be sure to not put too much reliance on being saved by protective devices.

author: vk6zgo
author_rank: Super Contributor
timestamp: November 09, 2011, 03:48:43 am
content: An AVO Model 8 on the 1000volt ac range connected between Active & Earth is a good tester for RCDs.Many moons ago,the Sparkies came in & installed an RCD on the workbench while I wasn't around.I had been working on a bit of faulty tube equipment.My usual habit was to check the incoming mains by hanging the AVO between Active & Earth,& Neutral & Earth in turn,rather than test across Active & Neutral,as it was more convenient to just poke around with one probe,with the other lead securely clipped to Earth.Imagine my surprise,when the whole bench turned off!There I was,scratching my head trying to figure out what could be wrong with the AVO to make what I thought was a new Circuit Breaker drop out.All was revealed when I took a closer look at the "Circuit Breaker"!That was my introduction to the wonderful world of RCDs!VK6ZGO