Somewhat OT electrical wiring-related question - Page 1
Forum section: electronics / general

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 02:07:31 am
content: OK, I've got one for anybody on here familiar with electrical work.As I've mentioned before on here, the electrical wiring in my house is a disaster, and I've been redoing it one small section at a time. (Yes, where I live, it's legal for me to do it myself.) I encountered something interesting today in the kitchen. In one outlet box, there's an extra three-wire cable; just the ground wire is connected in with the other ground wires in the box. (Well, "connected"... it was just twisted around them and about to fall off!) Line and neutral are not connected anywhere. I've probed the wires and determined that all three are floating at the other end as well. Obviously, I left the ground connected (properly this time), in case some dumbass decided to use the entire cable as a makeshift ground lead for god knows what.This isn't so much an electrical question as an installation/rework question: does anybody have any clever ways to ascertain where that cable goes? It just heads up the wall a ways and I can't really think of anything in the vicinity that would need a single ground lead. I opened a few nearby boxes to see if the other end was in them but it wasn't. It's right by an addition onto the house, so for all I know whatever it went to no longer exists and the wire was left. I'd really like to figure out where it goes to, but I don't care to start cutting into the wall right now...

author: Paul Moir
author_rank: Frequent Contributor
timestamp: July 09, 2013, 02:34:29 am
content: Given that's it's in the kitchen, the box might have been wired for a split plug. For those outside N/A, this is where you wire one socket of a duplex plug to one "phase", one to the other, and use a common neutral. This gives you a full 1750W on each socket, which is useful in a kitchen where you might have a toaster and a microwave plugged into the same duplex outlet.The only issue is it doesn't work out all that great for GFCI outlets, since these cannot normally be configured that way.Personally I'd go have a look down in the panel for a suspicious 3 wire coming in which is taped off.Also those wireless wire tracers are really handy for this sort of thing. They're pretty cheap these days. 'Course they can't see inside metal boxes, but they give you a hint.

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 02:48:49 am
content: Quote from: Paul Moir on July 09, 2013, 02:34:29 amYeah, that was my first thought, but the outlet itself appears to be as old as the entire house (not that old, really), and the metal tabs joining the two are intact. (Also, it's right by the kitchen-living room doorway and actually wired into the living room circuit.) Judging by the age of the house and the apparent age of the wiring, I don't think anything has been changed except for the addition.QuoteThat is agreatidea. I actually considered pumping an audio-modulated RF signal into the wire and tracing it with a handheld radio, but I'm a bit ashamed to admit I didn't consider somebody else may have had the same idea and made a product...I will definitely look into that, it will come in handy more than once I'm sure. I've got a couple disconnected grounds to trace out, as well...Even more OT: Anyone who installs an electrical circuit without labeling the breaker should be sentenced to a month of locating unlabeled circuits with nothing but a voltage tester and his feet. Anyone who cuts the wire too short to later cut off the original, now-crusty connection and redo it at least once should be sentenced to a month of cutting electrical wire with nothing but kitchen scissors. Anyone who incorrectly grounds an outlet?Five years' hard labor.

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 02:55:31 am
content: Quote from: Paul Moir on July 09, 2013, 02:34:29 amWait a minute.... unless I'm looking in all the wrong places, you've got a funny definition of "pretty cheap"!Oh well, I suppose I know how to make a low-power AM transmitter and stick it on the wire...

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 03:07:01 am
content: Quote from: c4757p on July 09, 2013, 02:48:49 amIt took me a whole day to go round my house and draw a map of which outlets are on which breakers. It doesn't help when the breaker panel is labeled with hand-written sharpie that turns out to be out of date (I think A/C was a later addition and someone reshuffled the breaker panel to add the new circuit).And what do you say to a single 15 A circuit that serves 19 outlets spanning four rooms?(Someone perhaps figured that the only thing you plug into outlets in bedrooms is lamps and alarm clocks, but what about electric clothes irons?)

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:19:57 am
content: Quote from: IanB on July 09, 2013, 03:07:01 amWhat I say to that is that if I can't stand in one spot and point to everything on that circuit, it's spread out too far.... I shouldnothave to figure out why the vacuum cleaner trips the breaker when it's the only thing plugged inin that room. Aunt Sally shouldn't have to be familiar with the layout of her house's wiring.As a suggestion to anyone dealing with poorly planned circuits: in rooms serviced by multiple circuits, like the kitchen, I've taken to writing the breaker number on the outlet, on the part hidden by the outlet cover. Some of them are split up too illogically for me to come up with an accurate and brief description to write on the chart, so I've found it really helps to be able to just pop off the cover and see which breaker controls it.And a question to people who live in places where you must have a license to do electrical work: Do you see quite as many shoddy crap installations as we have in places like this? It saddens me to think that I'm actually surprised whenever I see a residential installation done correctly.

author: MacAttak
author_rank: Unknown
timestamp: July 09, 2013, 03:25:49 am
content: Could be other explanations for it too.Since you said this is right near an addition, it could have been running to another outlet that doesn't exist any longer. The other end of that wire could be chopped off and hidden inside the wall anywhere.It could also have been damaged during the addition work, and depending on where it runs might just have been easier to run a new circuit to that outlet (via a different route) than it would have been to find exactly where the damage was and splice it with a junction box. For all you know, the former homeowner might have really liked the wallpaper in that room and didn't want the drywall disturbed. So the electrician might have been forced to run it through a different part of the house than the original run.Or it could also just be an extra length of wire that goes to a location in a nearby wall/floor/ceiling/light where they were considering installing an outlet or switch or fixture, but changed their mind after the wiring was run and the walls/ceiling drywalled over. There could very well be an unterminated loop of romex wire hidden away behind a wall where someone thought they might need it but didn't.Lastly, since you say this outlet is in your kitchen, I'm guessing it might be up at countertop level. There is a possibility that at one time in the past, this wasn't purely a double outlet. It might have been a single outlet plus a switch (or even just a switch by itself). That switch could have been connected to under-counter lighting or a pantry light, or track lights in the ceiling, or anything else. And those lights might no longer exist, so rather than leave live wires in a plastered-over junction box, they might have just disconnected them at that outlet. And maybe simply forgot the ground line. Or maybe left it attached because they figured there was no harm in it.

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:26:01 am
content: The surprising part is that our panel looks like it was wired by a professional electrician with severe OCD, with the exception, of course, of the unlabeled breakers. It's one of the few I've ever seen that actually resembles therepresentative photo on the Wikipedia article for "distribution board"- actually, the wiring looks a bit neater than that.But the professional electrician with OCD just ran the wires to the middle of each room, and old Billy Bob took over from there, with a beer can in each fist and a rusty old pair of wire snips in his pocket.

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 03:30:36 am
content: Quote from: c4757p on July 09, 2013, 03:19:57 amAfter I made my map I discovered that certain sockets located in hallways and other central locations were mostly provided with their own dedicated circuits for you to plug in the vacuum cleaner. Of course it might have helped if the house had come with a user manual that explained this. One thing that houses never seem to come with is an instruction manual...

author: MacAttak
author_rank: Unknown
timestamp: July 09, 2013, 03:33:07 am
content: Quote from: c4757p on July 09, 2013, 03:19:57 amA licensed electrician can still do a poor job.Also, once licensed, many don't give a crap about continuing education and the relicensing itself is sometimes a joke. I worked as an apprentice during summer vacations while in college, and my mentor would have to take the clerk/inspector out to lunch in order to get his license renewed. No test. No other paperwork. Just buy them lunch at a restaurant of their choosing.That's how it worked in New Orleans back then. Probably still does.Job inspections worked the same way. I had a lot of amazingly delicious lunches during those summers.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: July 09, 2013, 03:36:26 am
content: It could have been for just about anything, even a future garbage disposal.....you'll have to trace it out.My license is up to date by the way......both of them.

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 03:37:08 am
content: Quote from: c4757p on July 09, 2013, 03:26:01 amThe other thing I discovered is how time is money. So they fit sockets with push fit terminals for the wires, because someone can install them in 30 seconds per socket instead of 2-3 minutes with screw terminals. And they fit the cheapest sockets too so that eventually all spring tension is lost and the plugs just fall out of them by the weight of the hanging power cord...

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:38:19 am
content: On that note - maybe it's an unreasonable wish coming from someone with more of a programming background (think code comments), but I really wish it were standard practice for people doing electrical work to leave notes somewhere (a notebook attached to the breaker panel would be great) listing any "nonstandard" things they've done (like leaving a disconnected end of a wire) and saying what is there and why it was done.Unfortunately, even if professionals did that, there is alotof stuff around this house (not just electrical) that looks to be done by a barely capable handyman rather than a professional. You name it - interior walls, the rock wall that holds the yard back out of our deep, excavated driveway (now starting to cave in), some of the plumbing, some of the heating system, the deck (seven feet high on one side - we're on a steep hill - and not very sturdy), on an on...

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: July 09, 2013, 03:41:57 am
content: The only way to get what you want is to build it yourself, it takes a lot of time but the sweat equity is worth it.

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 03:42:12 am
content: Quote from: c4757p on July 09, 2013, 03:38:19 amHeh. You just described my house. The previous occupant was evidently one of those perennial "I can do it myself" incompetents who make a complete mess of everything they touch. What's worse is the builders who built it had the same disease. If only I had known what to look for when buying a house before buying a house...

author: Rerouter
author_rank: Super Contributor
timestamp: July 09, 2013, 03:45:53 am
content: not much better over in aus, our house used to be owned by a man with an apprentice sparky for a son living with him, we have so far had to rewire every last bit we have touched (yes by trades people) from no earths on outlets, to live and neutral reversed, and even makeshift junctions out of twist and tape earths included,one of the more fun bits was a fuse holder installed underneath the house away from the fuse panel running to an outlet that was removed, however the wires were left live and taped over, with neutral and earth twistedfor the kitchen extraction fan an extension lead was chopped and twisted into his mess,and the best bit, the oven and stove wiring was done on lighting wire, 1.5mm^2 single phase shared between them, (about 18A load), which was a more involved run going between the roof and floor 3 times, even though both the roof and under the floor are open enough to manage a single run by the fattest tradie you could imagine,

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:48:07 am
content: Quote from: IanB on July 09, 2013, 03:37:08 amYep. Another thing I'll mini-rant about - in the U.S., the outlet/plug design is unsafe enough that if a plug starts to fall out, live conductors are exposed. With that in mind, it should not be legal to manufacture and sell outlets that cannot maintain enough tension over a very long lifetime not to start dropping plugs..."Time is money" is one reason why I've said before that being able to do electrical work unlicensed is both a blessing and a curse. There's some truly shoddy work out there, but I love that I can take a weekend and do a whole bunch of wiring myself and do averygood job andknowit's done well. I know nobody is taking any shortcuts to save time.I know I sound like every "I can do it myself" incompetent out there who thinks he can do a good job, but I really do take a lot of pride in the work I do and I'm not ever satisfied with the handyman mantra: "fuck it, it's good enough".

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:49:03 am
content: Quote from: Rerouter on July 09, 2013, 03:45:53 amOh boy, something about that just screams "recipe for disaster" to me...

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 03:54:00 am
content: Quote from: Rerouter on July 09, 2013, 03:45:53 amThe outlet box I'm talking about had the earths twisted andnot even taped! And two of them (in a fat copper sausage with five earth wires) were loose enough that I could move them.I understand the "mentally retarded handyman" point of view on that: earth wires in the U.S. aren't insulated anyway, so why bother with insulating tape? The moron had obviously not heard of mechanical support before. Dear lord, a spare bit of Scotch tape would have been safer than what was in that box...

author: Paul Moir
author_rank: Frequent Contributor
timestamp: July 09, 2013, 03:59:02 am
content: QuoteSometimes, halfway through the job the electrician gets fired, and a decent one comes in. Usually the panel gets wired last.Electrical should look good. It's a sign of workmanship. Unfortunately codified laws don't make good workmanship.No, not the actual good wire trackers. This is the tracker I'm talking about:http://www.homedepot.com/p/Gardner-Bender-Wire-Tracker-Wire-Tracer-GET-4110K/202867889#.UduLNuGb29sJust an AM radio and a crappy transmitter. But at least you didn't have to lash it together right?

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 04:03:05 am
content: That is much more reasonable. Thanks for the link!I may continue building mine (I've already started designing the circuit), just for the nostalgia of building some sort of radio circuit...Though the notion of 1 MHz being "RF" kind of cracks me up...

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: July 09, 2013, 04:04:43 am
content: Usually if the work is done by a professional it gets inspected by the local authority having jurisdiction, and they catch stuff like that.http://www.homedepot.com/p/Ideal-Greenie-Grounding-Wire-Connectors-92-Green-100-per-Package-30-192P/202894282?keyword=grounding+wirenuts#.UduLHDtwqHc

author: Paul Moir
author_rank: Frequent Contributor
timestamp: July 09, 2013, 04:11:49 am
content: Quote from: c4757p on July 09, 2013, 04:03:05 amAh, 1MHz, the new DC... Over on the Beginners forum there's a post about routing a 32MHz clock; I remember when I first saw squiggly equal length PCB tracks and though they were pretty cool. I guess the grey hairs are beginning to show. (Clearly I was never an RF guy...)

author: c4757p
author_rank: Super Contributor
timestamp: July 09, 2013, 04:20:31 am
content: Quote from: Paul Moir on July 09, 2013, 04:11:49 amTheyarecool. PCB layout is one of my favorite things (it fulfills the same "puzzle" part of my life that most people use crossword puzzles for), and I just love it when the PCB is actually part of the circuit. The next things on my "test equipment junkie list" are a couple bits of RF stuff, and then I'd like to try to get into RF design.But yes, 1 MHz is DC. Anyone who has "high frequency"-type troubles at 1 MHz has clearly forgotten to take the wire off the spool before using it.

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 04:22:01 am
content: Quote from: c4757p on July 09, 2013, 03:48:07 amThey have a cure for that. When the plugs start dropping out they arc at the loose contacts, so now they have mandated the installation of arc fault circuit interrupters to meet code. Talk about curing the symptoms rather than the cause...

author: Monkeh
author_rank: Super Contributor
timestamp: July 09, 2013, 04:49:13 am
content: Quote from: 4to20Milliamps on July 09, 2013, 04:04:43 amBare CPCs, twisted solid cores, 'covered for safety' (it's called not working live).. The 70s called, they want their wiring practices back.

author: IanB
author_rank: Super Contributor
timestamp: July 09, 2013, 05:25:34 am
content: Quote from: Monkeh on July 09, 2013, 04:49:13 amSo how would you make a compact splice between three or more wires if you you couldn't use a wire nut?

author: Monkeh
author_rank: Super Contributor
timestamp: July 09, 2013, 05:26:51 am
content: Quote from: IanB on July 09, 2013, 05:25:34 amCage clamp, screw terminal..

author: AlfBaz
author_rank: Super Contributor
timestamp: July 09, 2013, 07:49:41 am
content: In oz we refer to them as BP connectors. Fairly certain BP stands for blue point, probably a brand name...They come in different sizes or amperage ratings. Single screw variety for active and neutral, double screw for earthI've only ever seen those twist on thingies inside cheap arse consumer gear

author: richard.cs
author_rank: Super Contributor
timestamp: July 09, 2013, 11:49:09 am
content: Wire nuts have been banned in the UK for decades, the twisted joints were unreliable, lacked machanical support, and had a tendancy for the conductors to snap off at the start of the twist. The wire nut has also been known to fall off leaving exposed copper.Modern UK practice is to use either crimps or screw terminals, although there is a move towards wagos at the moment:Chocolate block is common in the UK, and is similar to the Australian stuff linked by AlfBaz except cables can be inserted from both ends (but don't have to be) It comes in srips of 12 that can be cut down and used individually if needed.

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: July 09, 2013, 11:49:38 am
content: You folks are clearly NOT electricians.Those little screw terminal connectors are fine for small super fine wire, definitely not for 14 or 12 guage.

author: richard.cs
author_rank: Super Contributor
timestamp: July 09, 2013, 01:15:59 pm
content: QuoteThe largest size choc block in common use here takes 16 mm2conductors, that's just under 5 awg. So you can join two 5 or 6 awg wires end to end or splice 3 or 4 wires together each 8-10 awg. They come in many sizes for small or large conductors. Sometimes they're the most appropriate connector for the job, other times it's better to use a proper junction box like these ones:

author: Kevin.D
author_rank: Frequent Contributor
timestamp: July 09, 2013, 01:29:28 pm
content: those choc boxes are crap ,they feel really really cheap .I used those waggo boxes ,and waggo connectors the other week they seem really good .

author: richard.cs
author_rank: Super Contributor
timestamp: July 09, 2013, 01:39:56 pm
content: QuoteYeah they're not great but I'd use them for temporary stuff. Just happened that the photo I picked had one of those boxes rather than any other enclosure.

author: AlfBaz
author_rank: Super Contributor
timestamp: July 09, 2013, 01:55:25 pm
content: Quote from: 4to20Milliamps on July 09, 2013, 11:49:38 amif 14 gauge is about 2.5mm2 you can easily fit 3 x 7 strand wires twisted together with pliers in a standard 10 amp BP connector (ie the one shown in the picture)

author: dfmischler
author_rank: Frequent Contributor
timestamp: July 09, 2013, 02:03:38 pm
content: Quote from: AlfBaz on July 09, 2013, 01:55:25 pmIn the US, 14 gauge circuits are specified for up to 15 amps, and this is the minimum common circuit breaker size, so all connectors etc. must be rated for a minimum of 15 amps.

author: AlfBaz
author_rank: Super Contributor
timestamp: July 09, 2013, 02:40:30 pm
content: Quote from: dfmischler on July 09, 2013, 02:03:38 pmYeah we have 240V here so we don't need so many amps. Our outlets are generally rated for 10A. We do have 15A outlets that look very similar but have a wider earth pin so you can't plug a 15A device into a 10A outlet

author: SeanB
author_rank: Super Contributor
timestamp: July 09, 2013, 04:31:24 pm
content: I prefer crimped connectors myself, a lot more reliable if done right. Then again I use a lot of ceramic wire nuts as well, and have removed some that have been in place for 40 years plus ( install date on the fitting was 6 March 1967, it is almost the same age as me) that have given no problems over the decades.

author: Monkeh
author_rank: Super Contributor
timestamp: July 09, 2013, 04:50:19 pm
content: Quote from: 4to20Milliamps on July 09, 2013, 11:49:38 amI have screw terminals in use on 3 gauge. Screw terminals are actuallynotsuitable for fine wire (or fine stranded in general).

author: 4to20Milliamps
author_rank: Regular Contributor
timestamp: July 10, 2013, 10:11:49 am
content: You guys use 3 gauge for control circuits?No wonder you don't use wire nuts.http://www.altex.com/Belden-18AWG-2-Conductor-Shielded-Twisted-Pair-Cable-8760-BEL-P140298.aspxhttp://www.okwelectronics.com/pcb_terminal_blocks.html?gclid=CPKA86fUpLgCFY9xQgodVmQALwBack to the subject of wire tracing.....I've built both of those circuit tracer circuits and they work well unless the wire is in conduit or very far under ground, and since the grounds are tied together and in close proximity to the wires you are tracing, you will find the signal all over the place, so if you are going to design a circuit those things should probably be taken into consideration.