One of my wall outlets seems to not be grounded? - Page 1
Forum section: electronics / beginners

author: dentaku
author_rank: Frequent Contributor
timestamp: March 20, 2014, 09:23:01 pm
content: I got a new power strip from Canadian Tire this morning and plugged it into the outlet I have my analog oscilloscope usually plugged into.The "Grounded/Mise a terre" LED doesn't light up. When I plug it into the other outlets in the same room the LED is on so they all seem fine.I remember plugging my UPS into that outlet in the past and the Ground Fault warning light came on so I plugged it on the other wall.What makes an outlet act like this? My oscilloscope seems to have worked fine even though it's always plugged into that outlet.Is this a bad thing for my old BK Precision 1472C?

author: IanB
author_rank: Super Contributor
timestamp: March 20, 2014, 09:30:44 pm
content: Quote from: dentaku on March 20, 2014, 09:23:01 pmUsually when there is a break in the ground connection back to the distribution panel. It can happen, house wiring often has faults.

author: Falcon69
author_rank: Super Contributor
timestamp: March 20, 2014, 09:41:56 pm
content: Anything is possible.I hope you are able to fix it yourself. My roommate had to pay to have an electrician come and fix his electrical before I had got there. $700.00 for 4 hours of work, and still didn't completely fix the problem. In his bedroom, somewhere inside the wall, the bare copper wire which is usually ground, was connected to hot!It was shorting his TV out every time he plugged his coax cable from his cable into it. Fried two TV's before realizing what was going on. (Coax was arcing on the back of the chassis of the TV, NOT GOOD).It's amazing what you find in homes that you don't build yourself. Later, I remodeled his kitchen for him, I won't go into that, but I will say that it was worse than his bedroom.Sometimes old houses, especially the one I live in, has such old cable, all you have running through it is a neutral and a hot wire. No ground wire at all.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 20, 2014, 10:02:50 pm
content: Quote from: IanB on March 20, 2014, 09:30:44 pmConsidering my scope seems to work just fine on this outlet is there any reason I should avoid it?

author: IanB
author_rank: Super Contributor
timestamp: March 20, 2014, 10:10:12 pm
content: Quote from: dentaku on March 20, 2014, 10:02:50 pmYes, it is dangerous.Of course your scope seems to work fine. A missing ground connection will not stop it displaying signals on the screen.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 20, 2014, 10:25:39 pm
content: Quote from: IanB on March 20, 2014, 10:10:12 pmWell, I guess I'm going to have to figure out which breaker shuts off the power to that outlet and check it out.

author: Falcon69
author_rank: Super Contributor
timestamp: March 20, 2014, 10:31:10 pm
content: if this is a ranch house, or on an upper floor, do you have room to crawl in your attack? Running a new wire is fairly easy. Just get up there, string a new cable, drill a hole in the header of the wall, feed the cable down, re-wire into a new grounded outlet, then string the cable in the attic over to the wall where your panel box is, fish it down the wall into your panel box, and wire it into a breaker. It's not hard to do, should only take you about an hour. Just keep in mind that you'll want a grommet where you bring it into the panel box.I recently just did this to bring an updated outlet to each room in this old house....after the electrician installed a new 200amp panel box and meter. (i couldn't do that, city wouldn't have liked it).

author: VK5RC
author_rank: Unknown
timestamp: March 21, 2014, 12:25:57 am
content: Usually power circuits are wired in 'runs' from a circuit breaker on the distribution panel, it would be worthwhile finding out which power points are on that 'run' (by switching off the circuit breaker), the power points are usually wired with the physically closest to the distribution board often the 1st electrically as well, it may be an interupted earth either for the whole run, or just part of the 'run'. It is definitely worth solving!ps have you checked the active and neutral are correct as well?

author: pickle9000
author_rank: Super Contributor
timestamp: March 21, 2014, 01:05:09 am
content: You may have dropped the "box ground", switch the power off and pop the receptacle out. Do the easy stuff first.It's also possible for the main panel or any box in between to be missing the ground. These things happen with "handyman" type repairs. New plate covers are an excellent place to start looking.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 21, 2014, 05:16:35 am
content: Since all your other outlets seem to be grounded, It's probably a simple fix. If the ground in the outlet box is insulated, depending on your local codes and wiring methods, multifamily homes are almost always insulated here, it could be that a ground wasn't mechanically twisted together well before binding them with a wire nut. I've seen that a lot. Often times, insulated grounds will be stranded wire, which doesn't make a good "mechanical connection." Unlike solid wire, which a good electrician will twist tightbeforebinding with a wire nut, stranded wire wants to unravel.Point is, it's very likely a simple issue, but it could be just about anything. And it could also be the ground was dropped in a nearby box as well. Look to outlets and switches nearest to the one not working (assuming everything looks good in the outlet in question). Also check any boxes on the other side of the wall that may be on the same circuit (sometimes multiple circuits can also be in the same box, so be careful with that too.) A loose ground under a wire nut isn't uncommon.More I think about it... Local codes vary greatly. You wouldn't happen to live in a multifamily would you? If the wire is in conduit and the building is a little older, they used to allow the metal conduit to carry the ground. Stopped that about 35 years ago, I believe. Take some pictures of the outlet if you need more help. There are so many wiring methods, it'll make your head spin. It would help if I could see what yours is like.

author: nanofrog
author_rank: Super Contributor
timestamp: March 21, 2014, 02:44:46 pm
content: +1 on checking the easy stuff first.I had the same issue once, cut the power, opened the outlet, and discovered the screw had come loose on the ground connection over time. Very quick and simple fix in that instance, and you might have something similarly simple.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 21, 2014, 03:06:51 pm
content: Someone probably replaced the receptacle at some point and left the grounding conductor off.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 21, 2014, 03:11:40 pm
content: Well, I guess I know what I'm doing when I get back form work this afternoon.If it's not something simple like the ground wire not being screwed down I can always ask my friend down the road who has done electrical work before.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 21, 2014, 08:21:13 pm
content: Quote from: pickle9000 on March 21, 2014, 01:05:09 amThe quote Adam Savage"Now THERE'S your problem"That outlet is a mess.It has a big four conductor wire running into the box and only the black and white are used. No ground wire at all.I'm guessing my father did this back in the 80's.

author: w2aew
author_rank: Super Contributor
timestamp: March 21, 2014, 08:23:23 pm
content: Looks like there is enough romex in that box to strip back the sheathing and wire-nut on two pigtails - one for the receptacle, and one to connect to the box. Then you should be good to go.

author: nanofrog
author_rank: Super Contributor
timestamp: March 21, 2014, 08:25:37 pm
content: Quote from: dentaku on March 21, 2014, 08:21:13 pmI see a bare wire and barely a 4th with red insulation in the pic. What's the other wire color on the stripped/bare copper?And can you trace it back to where it's connected to (i.e. breaker panel hopefully)?

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 21, 2014, 08:39:00 pm
content: Looks like your standard 3 conductor romex with ground. Dead end circuit. Easy fix. Use a voltage tester first. Ensure that you have 120v between the bare wire and the black one.0v between bare and whiteWouldn't hurt to check the voltage between white and red too. That red may or may not be connected to anything. But, I'll bet there's a switch in the room that controls that red wire. Someone wanted both receptacles (top and bottom) hot all the time and just cut the red wire flush and replaced the outlet.Be careful with the red wire.... it's possible (though not likely) there is 120v on it fromthe other legwhich means it could be live, AND 240vac to the black one. My money is on a switch somewhere.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 21, 2014, 08:42:33 pm
content: Quote from: w2aew on March 21, 2014, 08:23:23 pm+1This is an easy fix, perfectly legal, safe and rather ordinary. You just want to make sure the ground goes back to the panel. Confirm with a meter.

author: Excavatoree
author_rank: Frequent Contributor
timestamp: March 21, 2014, 08:50:47 pm
content: I didn't know my father in law ever went to Canada and wired any receptacles - looks like his work.Fortunately, as someone said earlier, it's an easy fix. Don't forget to put a wire nut on that red wire.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 21, 2014, 08:53:33 pm
content: ... and lest you be tempted.... NO SOLDER!

author: IanB
author_rank: Super Contributor
timestamp: March 22, 2014, 01:02:24 am
content: Quote from: Excavatoree on March 21, 2014, 08:50:47 pmSeconded. That red wire could easily have 120 V on it. Leaving it chopped off and exposed like that is a very bad idea. When you put the outlet back into the box the wires get bent and squeezed together. If the bare end of the red wire was live and it touched a metal part of the (un-grounded in this case) outlet, you have a hazard just waiting for a victim.Strip back half an inch of the red insulation, put a wire nut on it, and wrap it in electrical tape for good measure.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 22, 2014, 01:22:37 am
content: Quote from: chipwitch on March 21, 2014, 08:39:00 pmYup, 120V between black and the bare wire, 0V between white and the bare one, nothing between white and red.I found a better, more modern receptacle downstairs so I guess tomorrow I'll switch off the breaker that leads to it and replace the whole thing.The receptacle seems to lead to a junction box that branches off to a bunch of other places including the water pump and the furnace. I then traced the wire going INTO this box and it leads to the circuit breaker section that's labeled pump and furnace.Lots of the outlets in the house are connected to breakers named PLUGS including the other two outlets in this room but this one seems to have just been added later so it shares with other stuff.By the way, why would you connect the ground wire to the box anyway?The junction box this wire goes to has the bare ground wire screwed into the box though.

author: IvoS
author_rank: Frequent Contributor
timestamp: March 22, 2014, 01:57:24 am
content: Quote from: dentaku on March 22, 2014, 01:22:37 amBecause it's a code.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 22, 2014, 02:39:03 am
content: Quote from: dentaku on March 22, 2014, 01:22:37 amYes, grounding the box is code, but it's really just customary on anything to ground anything metal that isn't directly electrified. The reason is because a chafed wire, broken down insulation, a gum wrapper in the wrong place or anything could inadvertently make contact with a hot wire (see that screw on the receptacle where the black wire goes? Pretty close to the box, eh?) and the metal box. Then you'd have a box that's exposed for anyone to touch and "zap". A lot of people don't know this, but the frame of the receptacle is in electrical contact with the box. And the trim screw that holds on the plate screws into the frame. If the box gets electrified and it's not grounded, anyone who touches that screw with bare feet on tile could conceivably be killed.There's also a less nefarious reason... If the neutral wire touches the box, or even if the box is mounted to a metal conduit that goes under ground, there may be a potential difference (voltage) between the box and the ground you're standing on. I've gotten mild shocks that way. Seen the same thing with a metal kitchen sink before too.If you can't ground the box easily, if you have a "self-grounding" receptacle, it will act as a ground for the box. It's no longer legal, by code, but it was legal up to about 15 maybe 20 years ago. Ground it if you can.Listen to the warnings about the red wire. They are valid. Though, stripping the wire and taping are overkill. The wire nut is sufficient. Whatever you do, don't cut it flush with the sheathing. Code says a minimum of 6" needs to stick out of the box. That "rule" is nearly ALWAYS violated by electricians because it isn't always practical. Just leave as close to that as you can and you're good.One more thing... that receptacle you're going to replace it with... if it's used, make sure you get the black and white on the right screw black is on the right, white is on the left as you're facing it with the ground jack down. Also, you will see two screws for the black and two for the white. Look closely, there is a small jumper that juts out a bit that electrically ties together those two screws. They're intended to be broken off to isolate the top and bottom receptacles in case you want to feed them with separate circuits or have one on a switch. Make sure the jumpers are there or else one receptacle will be dead. Of course, you can jump it with a piece of copper wire. 14awg for 15A circuit. 12awg for 20A.I hope I'm not being too presumptuous by volunteering so much info?

author: IanB
author_rank: Super Contributor
timestamp: March 22, 2014, 02:56:41 am
content: Quote from: chipwitch on March 22, 2014, 02:39:03 amBut the frame of the receptacle is also directly connected to the ground wire (if the ground wire is attached to ground screw on the receptacle). So ultimately all metal parts are connected and grounded. I know it may not be to code, but I don't feel too bad about grounding the receptacle and letting the box share the same ground. Sometimes it's fiddly to make lots of pigtails.QuoteEspecially if there are two or three cables entering the boxA useful trick is to form the cables into a spring like spiral inside the box before you connect them to the receptacle. Then they go back in much more easily than if you just try to squash them in randomly.QuoteI also noticed in the photo that the black wire is hooked the wrong way round on the screw. The screw tightens clockwise, so the wire should go the same way. That way, when the screw is tightened it winds the wire tighter into the screw instead of winding it off. There's also a fair bit too much bare copper hanging off in my opinion

author: IanB
author_rank: Super Contributor
timestamp: March 22, 2014, 03:04:10 am
content: Quote from: chipwitch on March 22, 2014, 02:39:03 amYeah, I want to ask about that."Just break off the tab. Put a screw driver in the slot and wiggle it back and forth and the tab will pop right off."Yeah, right. In your dreams. Put a screwdriver in the slot and try to wiggle it and the slot will break. Try to grab the tab with pliers and there is not enough room to grasp it or wiggle it.I'd like to know what mastermind came up with that design, and how exactly they think it is supposed to work? Am I missing some clever electrician's trick? Because I end up resorting to a Dremel and a cutting wheel

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 22, 2014, 03:22:16 am
content: Pair of Klein's (lineman's pliers). One jaw on theback, one on the tab. Squeeze. It won't break, but it bends. Then, put one jaw on thefrontand one on the tab. Squeeze. Usually comes off but sometimes needs another squeeze or two. Just keep alternating the direction you squeeze the tab and let metal fatigue do the rest.

author: pickle9000
author_rank: Super Contributor
timestamp: March 22, 2014, 04:13:52 am
content: In Canada it's perfectly legal to wire your own home provided you have a plan and get it inspected by the municipality (as far as I'm aware). You can get a simplified code book at the local building supply (Electrical Code Simplified House Wiring Guide) , it's province specific and it has all rules. The book is about 150 pages and is well diagrammed, it's updated whenever the code changes. I would recommend reading it even if you just want to understand what is in your walls.The receptacles you buy are well marked with wire strip lengths and colour coded screws (silver=white bronze=black and green is ground). Screws are Robertson (square drive) and slotted. The red handled Roberson driver is used for rough in and green handle for electrical connections (except in a breaker panel). For anyone that has not used Roberson screws they allow the screw to stay on the driver without assistance. Similar to a tight fitting cap head, really nice to use.Even though it's legal to wire your own home most people use a professional, repairs are common enough.15 amp circuits are the norm.

author: Clear as mud
author_rank: Regular Contributor
timestamp: March 22, 2014, 02:39:49 pm
content: Quote from: IanB on March 22, 2014, 03:04:10 amNo, it really is easy with just a screwdriver, if the screwdriver is small enough to fit in the little space. The trick is to use metal fatigue to your advantage, and just keep bending it back and forth until it breaks off. It only takes about 4 or 5 times going back and forth. You can use the same method to break a piece of wire with your bare hands, with no tools at all. Just take the wire and quickly bend it back and forth until it breaks. Sometimes it gets too hot to hold before it breaks, though. It helps to go quickly. Also in the case of the metal tab on the receptacle, you want to bend back and forth about once per second, not too slowly. Assertively, but not forcefully enough to break anything (besides the metal tab, of course).But I'm not sure why we're talking about breaking the metal tab, with regard to the original post. It's possible that the red wire is a switched hot that could feed half of the receptacle, but without knowing for sure where the cable comes from, we can't just assume that. Some testing or tracing of wires is required.

author: Clear as mud
author_rank: Regular Contributor
timestamp: March 22, 2014, 03:05:19 pm
content: Quote from: dentaku on March 21, 2014, 08:21:13 pmBefore modifying it in any way at all, I would trace that cable to where it comes from. My guess is that the other end also has only the black and white connected. To add a ground, you'll have to connect the ground at both ends. That's not too hard, assuming everything else is grounded. But if the box where that cable comes from is also not grounded, you'll have to connect ground there as well, and so on back to the main panel.From your description, it appears to me as if the outlet was added by someone else after most of the wiring was already done. It may have been your father, as you said. But whoever added it thought the ground was not important. Possibly they thought that outlet would only be used for a lamp, which doesn't even use the equipment ground. Or, possibly they thought grounded outlets were a new-fangled thing and not worth the effort to run a third conductor, since for so many years nothing had that extra ground wire. I've seen whole houses wired that way, with every ground wire cut off in every box. In fact, I've rewired a whole house that was wired that way, re-using each wire in a place where a slightly shorter wire was required, so that it would be long enough to connect the grounds which were originally cut too short to connect.If the red wire is not being used for anything, you could cap it off at each end, or you could replace the whole cable with one with only two insulated conductors, and re-use the 3 conductor one someplace else where you need the extra conductor. That looks like 14-gauge wire to me, so it should be relatively cheap and easy to work with, but if the circuit is 20 amps, it should be 12-gauge instead of 14. Truthfully, you'll probably be OK leaving it at 14-gauge even if it is a 20 amp circuit. I've seen whole houses wired with 14 AWG, where the original 10 or 15 amp fuses had all been replaced with 30-amp fuses, and the wiring operated for years like that without causing a fire. But you have to be aware that the probability for a fire is higher than if you used the correct size wire, and also that after such a fire, your insurance company may not cover the loss if they are aware that you were aware the wire size was too small.20-Amp circuits with 12 AWG wire are the norm around here (Oklahoma), but I'm well aware that in a lot of other areas, 15-Amp are more common because of the thinner and cheaper wire required.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 22, 2014, 03:06:19 pm
content: Quote from: chipwitch on March 22, 2014, 02:39:03 amYesterday I watched some videos on how to wire an outlet so I could visualise everything you said. It's always nice to have good information so thanks.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 22, 2014, 03:12:48 pm
content: Quote from: IanB on March 22, 2014, 02:56:41 amYup, the receptacle I'm going to replace the ugly old brown one with has the green ground screw connected to the tab that screws into the box so it'll be in contact with the box anyway.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 22, 2014, 03:15:01 pm
content: It was a reasonable guess... 3 conductor costs almost twice as much as two conductor. It's a dead end circuit, meaning the red wire was most likely intended to feed something in THAT box. Mentioning something as a possible or likely doesn't imply it is at the exclusion of all else. In the end, the red wire is irrelevant.Why is "some testing or tracing of wiresrequired?" The red wire wasn't connected to anything and the OP isn't planning on using it for anything. Whether it's hot, neutral, grounded or not connected is irrelevant. Put a wire nut on it and call it a day. Someone asked about the red wire. I simply offered a plausible explanation.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 22, 2014, 03:34:21 pm
content: Quote from: dentaku on March 22, 2014, 03:12:48 pmSounds like you have it under control. Isn't the internet a wonderful thing? I mean videos and everything! I suppose it's not real crucial, but be advised, as far as I can remember, the green screw has always been mechanically connected to the "yoke" or receptacle frame, but THAT is NOT what makes it "self-grounding." If you look behind one of the "ears," the part that the 6-32 screw goes through to attach the receptacle to the wall, you should see a little brass sheet metal clip that makes constant contact between the screw and the yoke. THIS is what makes it self-grounding (other implementations are possible).Look at it this way, a good ground can only occur if you have constant force at every junction ensuring contact all the time. Typically, the receptacle is supported by drywall, not the box. The screws make good contact with the box through the thread, but the receptacle is essentially "floating" free between the box and screw head. Before self-grounding receptacles, it was possible to apply a little force on the outlet, such as when plugging in a lamp, and the drywall would give enough to break contact between the yoke and the screw. Meaning, the ground could potentially be lost.Without that clip, I would urge you to make a proper mechanical connection. The romex has a ground. The box should be firmly grounded. So should the receptacle be grounded. I probably wouldn't be quite so concerned about cutting corners on this if it weren't for the fact you have test equipment plugged into it.Just to be clear modern code requires a ground wire firmly linking every box, outlet and switch, regardless of self-grounding devices. As I said, I might relax on this point in my own home because it wasn't that long ago the code said it was okay to rely on self-grounding devices, but I would insist on either self-grounding OR wire and screw connection.

author: Clear as mud
author_rank: Regular Contributor
timestamp: March 22, 2014, 03:59:08 pm
content: Quote from: chipwitch on March 22, 2014, 03:15:01 pmIt would indeed be nice if the red wire were connected to a switch on the other end, so that's why I would attempt to test or trace to verify. Because if so, then you can make use of that feature and split the outlet into a switched and non-switched half instead of simply capping it off.The other reason some further testing isrequiredis that the initial test that you suggested doesnotverify that the clipped-short ground wire is connected to anything at all at the other end. You said to test voltage between the white and bare and make sure that it's zero volts. A multimeter will read zero volts on that test if both are connected to ground back at the main panel as they should be, but it would also read zero volts if the other end of the wire were simply cut off, as this end is, which I thought was a more likely explanation than that the red wire is switched. One reason I thought that was more likely is that both wires are cut off. If they had simply had one electrician do the rough-in and another do the final installation, maybe they would cut off the red wire, not knowing that it was a switched hot. But they still would have connected the ground. The fact thatbothwires are cut off strongly suggests that this is a DIY repair and they simply only used two wires, which would also suggest that the other end of the cable may be done the same way.I think in a later post you suggested that the ground wire should indeed be tested for good ground, but you didn't say how to do it. A better way than verifying that white-to-ground is zero volts, would be to verify that black-to-ground is 120 volts. It still doesn't tell you whether it might have a weak connection, but it at least tells you it is connected.

author: pickle9000
author_rank: Super Contributor
timestamp: March 22, 2014, 05:02:11 pm
content: I would agree that the outlet looks like a handyman special. It would be nice to know if there is a switch on the red wire but as long as it is in the box and capped it's in code. The problem with this sort of stuff is that you can't see inside the wall. It's entirely possible this is an extension just tagged in, no box just tape and wires. The only way to tell is to open the wall or scope (endoscope) it. I had a conversation with an inspector (many years ago) and his opinion was this. If the outlet wiring is questionable cap it off / lock it out and put a blank plate on it or verify it, then put in a new outlet a couple feet away. If you are unable, do not alter or tie into to the circuit. The follow up was even a professional makes mistakes, the code is such that it encourages failures to happen in electrical boxes. Always have concern for the next person doing work on the system.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 22, 2014, 05:16:41 pm
content: @clear as mud... Man, you assume an awful lot.You assume he'd want a half switched outlet. He made no indication. You assume I was testing the ground for connection. I wasn't. I was testing to make sure the damn thing wasn't hot and THAT's why it wasn't connected in the first place. You assume that bare wire wasn't hot. I didn't. You know what they say about assuming... when it comes to electricity, it can fry your ass. The way it was wired doesn't "suggest" it wasn't done by an electrician... it WASN'T... period. Never assume a bare wire is safe to touch.You suggest testing the bare wire to hot... THAT's obvious. Especially, on a forum dedicated to electron-headed nerds like us all. If I say test the bare for ground, I have faith he'd know how to do that OR he'd ask. How many other people here suggested that bare wire might be hot? What if it had been?

author: dentaku
author_rank: Frequent Contributor
timestamp: March 22, 2014, 11:58:20 pm
content: I switched off the circuit breaker that leads to this outlet, checked it and it was dead.I removed the ugly old brown one and replaced it with the better looking white one, stripped back the wire, cut them all to the same length, capped the uesless red one that's connected to nothing at both ends, the connected the three wires.This wire is rather big gauge and ridiculously stiff to work with.Now my new power strip doesn't complain that it's not grounded anymore.

author: IanB
author_rank: Super Contributor
timestamp: March 23, 2014, 12:00:21 am
content: Quote from: dentaku on March 22, 2014, 11:58:20 pmTrue, dat. 12 gauge wire is surprisingly more painful to deal with than 14 gauge wire.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 12:10:32 am
content: Yay! Bravo Dentaku. BravoWell done.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 23, 2014, 12:48:02 am
content: My father said that he put that outlet in himself which explains why it's a piece of recycled 12 gauge wire with an extra conductor that probably came from a fish processing plant of some sort.I find it strange that the ground wire actually was connected to the box on the junction box it comes from downstairs

author: IanB
author_rank: Super Contributor
timestamp: March 23, 2014, 12:57:19 am
content: Quote from: dentaku on March 23, 2014, 12:48:02 amTake a look at all the devices you own with mains plugs. Count how many of them have three pin plugs. In America, doesn't it seem like a ground connection is an "optional extra"?

author: dentaku
author_rank: Frequent Contributor
timestamp: March 23, 2014, 01:28:59 am
content: Quote from: IanB on March 23, 2014, 12:57:19 amOther than laptop "power bricks" I've never seen a wallwart/plugpack with a ground pin.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 01:37:20 am
content: Or table lamps or lots of things. There's no reason to ground something that has no metal parts exposed but the prongs. What would you ground? Plastic? Ceramic or glass (in the case of table lamps).

author: nihilism
author_rank: Regular Contributor
timestamp: March 23, 2014, 01:40:03 am
content: Quote from: IanB on March 23, 2014, 12:57:19 amRegardless of the lack of use of the ground by many appliances, as mentioned before in this thread, you still need the box and any metal on the outlet grounded, in case an accidental short is made between that metal and an active conductor. Better to have a tripped circuit breaker, rcd (or gfi? as you guys call them) or blown fuse than an electrified human.No offense intended, but electrical installations in USA and Canada scare me. I think it is better here where only licensed electricians can do electrical work, it at least discourages people that don't know what they're doing from attempting electrical work. And you guys really just twist mains wiring together and use those wire nut things?? Just asking for a high resistance connection to develop, which can quite easily cause a fire, especially at the higher currents on a 110v system.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 01:49:55 am
content: There's nothing wrong with wire nuts. It's all in how they're used. The wires are required to make a good mechanical connection independent of the wire nut. In other words, the wires shall be twisted together in such a manner that they cannot pull apart without untwisting. Then the wirenut is only intended to act as a cap to insulate the bare wires and prevent the wires from untwisting. These things have been around forever and have an incredibly safe record. Your fears about them are wholly unfounded.

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2014, 03:32:04 am
content: Rest of us did away with damaging solid conductors with twisting years ago..Not to mention the amusingly exposed terminals and wire loop connections.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 04:45:38 am
content: That is so cute. Maybe if you blokes used a sensible voltage for powering your light bulbs, you'd find twisted wires more than sufficient a connection.

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2014, 04:46:46 am
content: Quote from: chipwitch on March 23, 2014, 04:45:38 amSorry, you've got it backwards, you're the one with twice the current to handle for no gain.

author: VK5RC
author_rank: Unknown
timestamp: March 23, 2014, 05:30:36 am
content: I also have to add that I think 230V is prob also 'safer' , at that voltage you tend to get less ventricular fibrillation induced.We do have the switches the wrong way around though, up should be on, so you can switch off faster.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 05:54:10 am
content: Quite right. Our currents are higher, true. But the problems you have with high voltage and ring mains. More people die in the UK (per capita) than in our system. (I'll let you look that up). Plus, the stats I see seem to dispute your safety record where fires are concerned. UK had 7763 residential fires cause by electrical fault in 2011/12 according to the Electrical safety council in the UK. Plus, more than 10,000 more electrical fires due to misuse!http://www.esc.org.uk/industry/policies-and-research/statistics/Based on 63 million population, 7763 fires equates to 1 fire for every 8100 Brits.In the US, our FEMA showshttp://www.usfa.fema.gov/statistics/estimates/index.shtmthat we had less than 30,000 (more like 28k) fires due to "electrical malfunction." Let's see, accounting for 317 million people in the US... Oops... only 1 electrical fire per 10,500 people (that number is even higher due to my liberal reading of the number of fires). Not to mention, in the US we have HOUSES, not your little girly "flats." HOUSES havecopiousamounts of twisted copper wire joints to spark, heat up and plague the lives of innocent, unsuspecting stupid Americans.You know, for all the talk about American "exceptionalism," a thing I detest by the way, maybe it has something to do with every little piss ant wanting to whip out his genitals to compare sizes. I don't know why so many people are concerned about being "better" than someone in another country ordoingthis or that better, rather than looking to their own and just trying to make theirs the best they can. Truth is.... I DON'T CARE if it's better over there! What I do care about are FACTS. And people perpetuating bullshit based on little more than myth, conjecture and just plain wishful thinking really annoy me. I get enough of that from my fellow Americans. I have always harbored some fanciful notion that Europeans were a little more rational. France, being the seat of Reason. Apparently, proximity is no guarantee of like-mindedness and American "exceptionalism" is universal. I can die now in my own despair, that there is no escape from such foolishness. Seems perhaps I'm being punished for my doing a little of myownbrand of "wishful" thinking.The truth is no one thing makes either of us better. For everything you can pick on us about, you leave yourself open to criticism. It's an endless cycle that leads nowhere. Getting back to my point. Wire nuts have been around a long time and are perfectly safe, taking into account cost/benefit.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 05:56:08 am
content: Quote from: VK5RC on March 23, 2014, 05:30:36 am

author: nihilism
author_rank: Regular Contributor
timestamp: March 23, 2014, 06:08:47 am
content: Quote from: chipwitch on March 23, 2014, 05:54:10 amNo ring mains in au. i also think that ring mains are a crazy idea.

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2014, 06:17:49 am
content: Quote from: chipwitch on March 23, 2014, 05:54:10 amQuoteTry that one again when you know the difference between a ring main and a ring final.QuoteNot of shock, you've got us flat out beaten there.QuoteNow let's head over to some other statistics, from the NFPA, and find that number is suddenly 47,000 when you factor in equipment (like with the 7763 figure you used from the ESC):http://www.nfpa.org/research/reports-and-statistics/fire-causes/electricalOops, I sunk your invalid-comparison-ship.Do you want to dispense with the cheap shots now?

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 06:30:25 am
content: Monkeh, did you not see where I said, "I DON'T CARE?" What's the phrase you Brits use? Oh yeah... PISS OFF! At this point, anything you have to say is specious.

author: Monkeh
author_rank: Super Contributor
timestamp: March 23, 2014, 06:32:42 am
content: What a delightful fellow you are. I also saw where you said you care about facts.. right after mangling them to suit your purposes. You could just, y'know.. not reply.

author: IanB
author_rank: Super Contributor
timestamp: March 23, 2014, 07:12:37 am
content: These never ending "my electrical system is better than your electrical system" debates do get a bit tiring.And who the hell cares whether it is a "ring main" or a "ring final"? Pedants of the world unite! Over in the UK Joe Public calls those big metal structures electricity "pylons" too! And guess what? So does the National Grid!Having grown up with the UK electrical system, and in recent years become exposed to the US electrical system, all I can say is they both work. Local customs may be different, but they are both functional. I have seen far more problems caused by bad workmanship than by bad regulations.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 07:22:32 am
content: SlowExactly!

author: nihilism
author_rank: Regular Contributor
timestamp: March 23, 2014, 08:26:52 am
content: But they're both crap and the Australian electrical system is better.

author: SeanB
author_rank: Super Contributor
timestamp: March 23, 2014, 08:49:45 am
content: Both are safe if installed, used and maintained properly. There is the problem, in that you find that parts degrade, are installed wrong or poorly but still work for decades.Here you have weekly reports of people killed by illegal connections, that often use a bare conductor, made from whatever is easily stolen, like fence wire, phone cabling or even existing fences, with an earth return. Protection is whatever burns out first, and there is no political will to stop this continuing. There are minisubs with illegal connections on both the LV and MV side.

author: sean0118
author_rank: Frequent Contributor
timestamp: March 23, 2014, 09:36:57 am
content: Quote from: dentaku on March 20, 2014, 09:23:01 pmSeeing that we are already off topic, can anyone explain how this sensor works?

author: G7PSK
author_rank: Super Contributor
timestamp: March 23, 2014, 09:55:40 am
content: Its about time we had a world standard for the mains voltage and frequency. How about 180 volts and 55 HZ, that way we need not argue about who is best.

author: SeanB
author_rank: Super Contributor
timestamp: March 23, 2014, 10:59:58 am
content: Quote from: sean0118 on March 23, 2014, 09:36:57 amVery simple, they have a resistor to bleed a small amount of current ( likely the resistor used in the power on indicator for the strip as it is there already) and have another indicator to show if there is a voltage between earth and neutral of at least 30V. So long as the current through the resistor along with any current through the Y capacitors is kept below the trip level of any RCD device it will work to detect a floating earth. Only disadvantage is that a floating earth can result in a low current shock hazard on the equipment metal housings from this detection current if the earth is open circuit. It will be detectable but not too dangerous.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 23, 2014, 05:35:47 pm
content: Quote from: SeanB on March 23, 2014, 10:59:58 amI was wondering that too after I fixed my outlet and saw the indicator light up.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 06:17:36 pm
content: dentaku, I want to apologize for my role in taking your thread off topic. It was inconsiderate and inexcusable. I am glad, however, that you're up and running again.

author: dentaku
author_rank: Frequent Contributor
timestamp: March 23, 2014, 09:35:25 pm
content: Quote from: chipwitch on March 23, 2014, 06:17:36 pmMost threads are off topic once you see them go past two pages.Luckily nobody argued Philips head screws versus the superior Robertson screws or funny green un-colour-coded American money, that would have gone off topic WAY faster

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 10:13:12 pm
content: pfft...

author: madires
author_rank: Super Contributor
timestamp: March 23, 2014, 10:30:40 pm
content: Quote from: chipwitch on March 23, 2014, 01:49:55 amTwisting mains cable together? Ever tried that with multiple 2.5mm² (AWG 13) wires? We're using connectors likethese. Simple to use, safe and you can also remove wires easily.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 23, 2014, 10:57:32 pm
content: Try multiple 6 AWG, about the largest I've seen done with wire nuts. Anything larger than that, we'd either use a split lug or multi-taps with friction tape.

author: pickle9000
author_rank: Super Contributor
timestamp: March 23, 2014, 11:17:44 pm
content: @madiresThe large mains cables always go into a block on a breaker panel. Large appliances that use larger cables will typically be run panel to socket. We have one style for a dryer and one for a stove/cooker. It is possible to have a large cable joined but in new construction the inspector would just say "run a continuous line".Below you will see a push in variation to the wire nut, these are widely used in new construction. The big black guy is a wire nut variation with a screw in it. These are rarely used but do exist. The wall outlets also support the push in connections (except for ground).@chipwhichUnfortunately the musical stylings of William Shatner are ours as well. Hopefully the discovery of insulin makes up for that in a small part.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 24, 2014, 12:04:37 am
content: Quote from: pickle9000 on March 23, 2014, 11:17:44 pmI hope none of my remarks have been misconstrued to mean I harbor any "fault" of any kind with any country. I think there's more than enough blame for all of us (countries) and it would be intellectually dishonest to think otherwise. When it comes to cruel "gifts" to the world, I think we've managed to outpace William Shatner by more than a modest margin, to speak conservatively. But, hey... you guys gave us hockey! I think you guys are paid forward for quite some time!

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 24, 2014, 03:48:05 am
content: Quote from: IanB on March 22, 2014, 02:56:41 amIt's code because it and anything further on that is grounded to the box becomes a floater if the receptacle is removed for service.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 24, 2014, 12:49:19 pm
content: Quote from: Mr. Coffee on March 24, 2014, 03:48:05 amThis is true. I was the one who originally suggested it would be "okay" to rely on the self-grounding receptacle to ground the box IF grounding the box was difficult. I failed to mention I was only referring to THIS particular case. It hadn't occurred to me before you pointed this out that someone else might read what I wrote and think it was okay... especially simply to avoid making a pigtail!Some older boxes don't have a threaded hole for a ground screw and in THIS case, being a dead-end receptacle, bending the rules a bit could be overlooked. However, it's NOT the best practice for the reasons you state. I wouldn't have suggested it had it not been a dead end circuit. But you are quite right...

author: IanB
author_rank: Super Contributor
timestamp: March 24, 2014, 02:32:21 pm
content: I know why youshouldground a metal box.But I'd just like to point out that if the box was metal and floating, and I removed the receptacle for service without first cutting power to the circuit, then the exposed terminal screws on the side of the receptacle are far more dangerous than the metal box! Those screws are definitely hot, whereas as the box only has the remotest possibility of being hot.If the electrical code really cared about safety, it should insist that receptacles are designed without any exposed metal parts that are hot during operation.

author: w2aew
author_rank: Super Contributor
timestamp: March 24, 2014, 03:37:00 pm
content: Quote from: IanB on March 24, 2014, 02:32:21 pmGrounding the box is to protect you from something hot that might touch the box (stray wire, screw terminal on receptacle). If the box were floating and was touched by something hot, then the ungrounded box would be hot (dangerous). Where, if the box is properly grounded, then something hot coming in contact with it would cause a short, trip the breaker, and keep you safe from touching a potentially hot box.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 24, 2014, 03:53:54 pm
content: Quote from: chipwitch on March 24, 2014, 12:49:19 pmYou can usually use a clip type attachment intended for attaching an equipment grounding wire to the lip of a metal box if local regulations allow.I just always figure that the house will probably be there 100 years or more. I try to watch out for the next owners, and the next, etc. They (and their exploring toddlers) won't know what you did or didn't do to the house wiring. That's just my practice.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 24, 2014, 04:56:17 pm
content: Quote from: Mr. Coffee on March 24, 2014, 03:53:54 pmIf your exploring toddler is servicing your receptacles, I'd say you've got bigger issues.At some point, given the medium, you have to choose what's really important. Otherwise, we could have just inserted the entire NEC and instructed the OP to figure it out for himself. I don't know who it serves more by being picayune, the OP or posters showing off their knowledge. Ground clips can do more harm than good in the hands of a DIYer. Is that subjective? Yup... along with just about everything else people want to argue (likemyelectric mains are better thanyours). There is no such thing as 100% safe in anything. And you can ALWAYS do thingsmoresafe than this way or that and eventhatis often subjective. If the OP topic was a debate on electrical safety, such remarks would be appropriate. Since the OP was searching for a practical solution to his problem, found it, made repairs and tested it back a couple pages ago, I'd say the medium worked. And it is safe within a practical margin (as is EVERYTHING printed in the code book). Besides, as far as we know, the OP used a proper ground screw attached to the box rendering your comment rather moot and off-topic.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 26, 2014, 03:56:01 pm
content: How could my post about the possible use of a grounding clip be any more moot and off topic than your previous post when you are the one that raised the issue that the OP's box may not have a threaded hole for a ground screw? I was just answering the concern.

author: chipwitch
author_rank: Frequent Contributor
timestamp: March 26, 2014, 06:37:18 pm
content: It was moot because he already had it done and tested.

author: Mr. Coffee
author_rank: Regular Contributor
timestamp: March 27, 2014, 03:52:42 am
content: Quote from: chipwitch on March 26, 2014, 06:37:18 pmMy bad.