BACKSTAB wiring troubleshooting
toolbear
| Posted in Energy, Heating & Insulation on
Folks,
One of our Habitat crew leaders has what sounds like backstab wiring failure. Four of his outlets are suddenly off line. Place built in the ’90s.
What methods of troubleshooting backstab wiring failures do you find effective?
He has no circuit mapping so what runs where is unknown.
The ToolBear
“Never met a man who couldn’t teach me something.” Anon.
Replies
Go back and redo all of the connections and never backstab. There are circuit tracers that allow for hidden wiring. Google them and look for the kind that are very sensitive. Otherwise, kill the power and use a continuity tester on the ground wires to find the routing. Chances are, if the hot or neutral went away, all three didn't so find what lost its connection and use the rest to trace it out, then document everything.
I would start by finding out which recepticle had a high current draw appliance plugged into it. Do a visual for black marks on the plugs and recepticles.
> Otherwise, kill the power and use a continuity tester on the ground wires to find the routing.For that to work you'd have to disconect the ground wire at the breaker panel.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
That's fine, I just didn't mention it. It's late, I'm tired.
"I cut this piece four times and it's still too short."
Just use your intuition to guess what feeds what. The failure may be at either the first failed outlet or the last "good" outlet.
Check whether the failure is to neutral or hot. If neutral failed then you can use a circuit tracer to follow the wire in the wall from outlet to outlet.
In any event, you'll have to pull out each suspect outlet. Probably as soon as the "guilty party" is pulled out of it's box the connection will go "good", at least briefly, so it's good to keep some sort of indicator (a corded drill, with the button locked on, eg, or a fan) plugged into a failing outlet so you'll immediately see/hear when the connection is made.
Just FYI, the only time I've personally seen a failed backstab connection was when the electrician (and I suspect it was a "pro") erroneously stuck the wire into the release slot instead of the wire hole. It might be good to give the "easy" outlets a quick look-see to see if this is possibly what happened.
You have 3 wires. If any two of them are good you can use a signal tracer on them.And in fact I I have had some luck with using just one wire. Don't hve the range.But one trick that I stubled on and later saw written up some place was to use tone generator on a fish wire. Then you can locate where it is on the other side of the DW.
Sorry how does the tone generator trick work? Are you saying that you use the fish wire and when you want to locate its end within the wall you hookup the end that entered the wall to the tone generator and then take the tone detector and use it against the wall to find where the fish wire got stuck? I take it the tone detector can detect the tone through the drywall? Interesting idea.
The tone generator is just a 2 kHz or so audio generator. Normally to get a large enough electrical field you need two conductors. But you will get some with the single conductor of the metal fish tape. And the sensor is just an amplier with a speaker that senses the electric field.So yes, it works through any non-conductive material.
Yeah, there are several ways you can use a signal tracer. Worst case you can use another wire strung on the floor to complete the circuit.With a HF tone generator you don't need to complete the circuit, though pickup will tend to be less accurate.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
I worked for a home systems integrator and the one I used had a pair of wires with clips on the ends and actually plugged into a receptical for power, with another box with an egg-shaped sensor on a wire. If the sensor was within about 8' of the wire with the signal on it, you would start to hear the tone and it got louder as you moved it closer. Unforutnately, I don't remember who makes that one. There's another one called "Fox and Hound", which is another two piece set. They sell them at Home Depot and other places but they aren't cheap. Have you tried calling an electrical supply house and asking what they have for this kind of job? Since it's easy enough to find the circuit that is affected, with the wires for that one lifted, it should be easy enough to find where the problem is by using a multi-meter and checking for continuity.
"I cut this piece four times and it's still too short."
Yeah, I have a GB plug-in style circuit tracer. Not totally fantastic, but pretty good for tracing a circuit through walls, etc. It requires power from the outlet, though, so if that's missing due to a bad "hot", the "hot" will need to be "borrowed" from another circuit. If the neutral is out, the ground can be used instead.There are battery-powered tracers that work similarly to this one. They generally have a capacitor in them so they can be plugged into a hot circuit or a dead one, but if dead the wires need to be shorted at the other end.High-frequency tracers use a signal above about 10KHz to turn the wire into an antenna (where as the above units rely on induction between wire and detector). Th HF tracers allow you to follow a single "dead" wire, but don't work as well on one that's grounded (or otherwise "terminated") on the other end, and don't allow for as precise location of wires.For the really exotic, get a TDR unit. This is essentially "radar" for the wire. It won't tell you were the fault is, but it will tell you how far away it is, and each outlet or other connection along the way will show up as a "blip".
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
If you can hear the tone well, it's not 10KHz, more like <1KHz. I know the type, though. The sensor is like an amplifier with an improperly grounded input, which makes it into a good antenna. Another device that will tell the actual distance to the open is called a reflectometer and is used in low voltage systems, like phone, network and vodeo (coax). There may be something like this for electrical power wiring.
"I cut this piece four times and it's still too short."
Folks,
Thanks for the ideas. I copied the thread to Word and will mail it to the homeowner. Bet the wires are crammed into some undersized box, through-wired at the outlets, not a pigtail in sight.
Lacking tracers, I usually try to find the last hot box and the first dead one and see what is what. Unlike alum. UFer, I don't think he has wire rot.
Noticed that no one suggested it was a cause other than backstabbing gone bad.
I sidewire or use commercial spec backwire outlets. I would not make it wiring tracts.
Like the way the electician is wiring this Habitat job. All the boxes are deep. Love those 22 ci 1 gang boxes. He even ran smurf pipe from all the phone/cable drops into the attic to ease any later renovations. Even the panel is spacious.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
I take it he didn't use a structured wire approach and have one communcation panel where all the coax/ethernet/phone/fax are hooked into hubs? I am thinking about putting in a structured wiring panel for the above plus lights and a central heating computer that will talk to all thermostats. For lighting I found one dealer - http://www.centralite.com. I still have to look into a heating computer - they are mostly for commercial buildings and I haven't really looked into pricing them out but I think a centralized programmable thermostat system would be well worth buying if it pays back in 10 years. Anyone have experience with central lighting or heating systems?
With 10KHz you can hear the tone if it's modulated or if you beat it against 9KHz. Depends on what scheme is used. 1KHz doesn't radiate very far.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
I have several different ones.I have a #39.95 Idea Circuit breaker finder. Which sorta, sometimes almost works.This is an updated version. http://tinyurl.com/ynzpdg
Don't know if it works any better. The problem is that the probe does not realy discriminate enough and you are lucky to get within a breaker or two. It uses an RF and you can pick it up on an AM radio. So basically I use the radio and forget about the probe. Then I flip breakers until the signal stops. Worked on one house that has a 320 amp service with dual 150 amp main panels. One of which feed a sub-panel. One a couple of breakers where labeled and I think that was because of an additional circuit added to panel years ago. Trying to ID the breakers and with at least one I got hits on both main and the sub-panel. And I finaly found that it was on one of the main panels. I have not found it reliable enough to try an trace wires in a wall. But it sometimes gives good clues.But I have found tha you can run around the house with the radio and quickly spot what other receptacle are on the circuit.It requires AC to work.There are a number of more expensive versions. And Ideal says that there receiver has self adjusting sensitivity.Here are a number of them.http://www.professionalequipment.com/circuit-tracers/I have a cheap GB tone generator and probe for LV work. http://www.smarthome.com/90502.htmlIt works. But it has limited range. Has a cable, phone, and clip lead connectors covered with a clamshell back. That the probe stores in a slot.It is handy for connection to a cable and going to the other end where you have a bunch of them to ID which is which. The main problem with it is that it has a push button on/off on the front and if you carry it in a tool box it is always being hit, turned on and the batteries drained. The other think is that it also has auto off. So you might be runnin around a building looking for the other end of the cable and the transmitter has turned itself off.Then I got one of the Extech/Progressive/Greenlee Tone genertor/probes.http://www.professionalequipment.com/wire-tracer/I have not sure what the difference is between the versions, except I see one uses a filtered probe I guess to keep 60 Hz out of it. And there are several version of the transmitter. It is designed for telephone work with a phone plug and polarity indicator. But it also has clip leads and will work with an UNLOADED circuit.But it does limited work on loaded circuits or single ended circuits (such as clipping one wire on a fish tape.) But the range is real limited. I got it hopeing to trace some landscape lighting circuits. It would not do that because of the load of the lights. But hooked it up single ended. And then go to another place where there was a cable and see if it was on that circuit or not. But it is not real reliable.It uses an audio signal and capacitive pickup. I had to move an audio system from one house to another. It had a power amp for distributed sound driven from a Bose Lifestyle system with it's own powered sub-wolfer and local speakers.The HO could not tell me how the thing was setup or why some of the strange connection. so I needed to ID what wires at the amp drove which speaker. I hooked the generator up to the wires and was planing on going to the different speakers and disconnection them and using the probe. However, I could hear the tone coming from the speaker. So that made it real easy to ID them.Now you mentioned Fox and Hound. I just thought that slang for a generator/probe. But I see that it is a brand.http://technicalconnectionsinc.stores.yahoo.net/witrkitworfo.htmlAnd searching for that I see found a shematic for a RF signal generator. It is self powered and works with a radio.That might be handy to have.http://www.uoguelph.ca/~antoon/circ/foxhound.htmlNow if you look there are some $400 PLUS units. And I have not looked at the details of them, but some say that they will work on hot and open and shorted wires. One of the the probe will work in both capacitively coupled mode (which is what the Progressive units use) and inductive where you have closed loop.http://www.professionalequipment.com/wire-tracer/
http://www.professionalequipment.com/circuit-tracers/Also a while back someone posted a link to a TDR that could be set to with with different electrical cables (NM, UF, etc). It was "reasonably" priced if you did that kind of work all the time. I think something in the $700-1500 range.
"Just FYI, the only time I've personally seen a failed backstab connection was when the electrician (and I suspect it was a "pro") erroneously stuck the wire into the release slot instead of the wire hole."You mean like this one I found last week?BruceT
Basically the same. It was on a switch, IIRC, and a little different design. But essentially the same thing.
Seven blunders of the world that lead to violence: wealth without work, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, worship without sacrifice, politics without principle. --Mahatma Gandhi
usually I would think how I would run the circuits if I was was wiring the house. but first I would check for any gfi outlets or breakers that could be tripped, usually I go from the service panel to first junction box of a run and then on to the next box. so I would start with the dead box closest to the service panel, pull the outlet and check for power, if no power I would go back to a box that is hot, pull the outlet and check wires to see if there is power passing through the outlet, if there is power check the nuetral wire as well to be sure there is voltage across the hot and neutral. if there is power coming into the first dead box then the problem is in that outlet or a connection. again do not over look the neutral wire as the culprit. if this doesn't solve the problem, I would take each outlet out and inspect wiring and connections, also do not overlook switch and or light boxes although outlets should be on 20 amp and lights on 15 amp and not be in the same boxes. try this and if that doesn't work we'll get a little more involved.
orbs
Are the outlets in "high moisture" areas? If so, they might be wired off of the load side of a GFCI which has tripped.
Youth and Enthusiasm Are No Match
For Age and Treachery
A rule I follow is "Make your two best guesses, then start over, and be systematic."
Backstab failures? I've seen a few; many seemed to be a failure of the receptacle itself. When you remove a coverplate, and half the receptacle comes along... that's a 'clue' :D .
Much trouble would be avoided if circuits were mapped before there was a problem. That's where your first effort lies: determining just what circuits go to which outlets.
Next is to open the 'dead' receptacles until you find one that is "end of the line," that is, has only one set of wires to it. This will give you an idea as to which one of the remaining receptacles is the 'first' one without power.
Your failure is either at that receptacle, or the one before it.
Remembering that the circuit is still LIVE, check that receptacle for power in the box; this is best done with one of those 'tic' tracers (the pen like things that sound off in the presence of electricity). If there is power indicated, turn it off, and then take the box apart to examine and fix.
If there is no indication, open the connections, and verify with a real meter. Or, better yet, a 'wiggie' that applies a load to the circuit as well. Broken wires will often show a 'ghost,' or false reading on the wire.
Are there any wires in the box that are not accounted for? Wires that lead to a switch, perhaps? Here is where a toner, or even continuity meter, can be used to identify which wire goes where. Of course, to use a toner, you need one that works on a dead circuit; expect those to cost over $100.
(Such a toner will be destroyed if applied to a live circuit)
It helps to be able to visualize the structure inside the walls, to be able to guess how the guy routed the wire. You did say this was a 'habitat' home; such are usually made in multiples, and there may be a similar unit nearby, that you can use for comparison.
You also get to crawl through the attic and crawl space, tracing out the wires.
One advantage to a "habitat" home is that it is a minimal house; there are fewer things to check.
I would also be suspect of any additions / changes / repairs made since the place was completed. Don't be surprised to find the trouble at a flying splice that was added for the Xmas lights!
@@ One advantage to a "habitat" home is that it is a minimal house; there are fewer things to check.
Was on a remodel project in a $6 mil mansion in Emerald Cove on 2004. Four floors, pool, elevator, etc. and miles of cove molding. Nice views too.
Number of outlets in the garage? One.
Number of outlets in a habbie garage? One or more. In our Cypress project there were four - all at different heights. The ToolBear
"Never met a man who couldn't teach me something." Anon.
Hi,
I am wiring my basement workshop. Should I avoid making the connections to new receptacles using the backstab wiring portion? Am I right in understanding that by backstab you mean; the connectors on the back that you put the wire directly into, instead of the screw post connectors on the side? I have tightened the screws very firm when using the backstab connections. Thanks for the information.John
There are three different ways of connecting outlets:-- Side wiring (using screw terminals in the fashion you learned in elementary school)-- Back stabbing (poking the wire end into a hole in the back where it is grabbed by a spring in the outlet)-- Back wiring (poking the wire end into a hole in the back such that when the side screws are tightened a plate presses against the wire and holds it tight)Back-stabbing and back-wiring are mutually exclusive -- a single outlet can't be designed to do both.Back-stabbing is generally regarded as poor form, not only with friends, but when wiring outlets. The connection made is unreliable and will at best be marginal to handle the design current.Back-wiring, on the other hand, is the preferred way to wire, when the outlets are the type that permit it.
Seven blunders of the world that lead to violence: wealth without work, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, worship without sacrifice, politics without principle. --Mahatma Gandhi
DanH gave you the straight pro scoop. You mentioned tightening the screws when "backstabbing", unless the device is true "backwire" they have no effect other than making the width of the beast less.
Backwire is preferred in most cases as it is much simpler to strip to the strip guage length and insert it fully and tighten. While it is not rocket science, making the proper loop on sidewire seems to be a problem for some who do not do it for a living or at least often.
@@@ I am wiring my basement workshop. Should I avoid making the connections to new receptacles using the backstab wiring portion? Am I right in understanding that by backstab you mean; the connectors on the back that you put the wire directly into, instead of the screw post connectors on the side? I have tightened the screws very firm when using the backstab connections. Thanks for the information.
Dan has covered the field nicely. Read the fine print on the device and if you backstab, you are limited to 14g wire and 15A circuits, neither of which you want in your shop unless for lighting.
For a shop, I would use commercial spec. backwire outlets (HD has them). You can back or side wire with them. Go and compare one to the .49 outlet. Notice a lot of differences? If they can retail that for .49, how much value went into it?
When I can, I overwire shops - 10g in lieu of 12g for voltage drop, at least one 240v/50A circuit for welder or compressor or ____. A 240 circuit down both sides of the garage to the door is nice. A 240/30A circuit for lesser tools. A 120v20A balanced circuit down each wall with frequent outlets, etc.
All the runs are in surface mounted EMT and 4" drawn J boxes. (Unless you are new construction. Then you can put it in the studs.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
@@ You did say this was a 'habitat' home; such are usually made in multiples, and there may be a similar unit nearby, that you can use for comparison.
I hope I didn't give that impression. The guy was on my wiring crew yesterday at a Habitat project. The problem is in his home in Mission Viejo. Four dead outlets.
Habbie homes are generally built to much higher standards than the tract homes. We normally sidewire everything, there is 100% sheathing, etc. Did a project with Lennar Homes. Where it called for sheer, it got sheer. Rest was blueboard. Ours are all sheer.
(There are exceptions. Our Geezer Gang did the Cypress wiring. It made my teeth itch to look at it. None of the flow and grace that marks a pro job.) The ToolBear
"Never met a man who couldn't teach me something." Anon.
I did misunderstand, and thought you had said the problem house was a 'habitat' home. Don't read more into that than there is. It is to your advantage, in tracing the problem, that the circuit be as simple as possible- and that there be a 'working model' nearby which you can examine. In many cases, the same statements can be applied to older (but not too old) tract homes. Despite the trade bias, at this point you don't "Know" that the problem is backstabbing. Assume nothing. I did mention possible changes, made to the original wiring, as a likely source of the problems. The hardest part is to set down your toolbelt, step back, get out the pencil and paper, and take a good, long look at the place. You will be locating every receptacle, and mapping every circuit. Or, pretty darn near! You will need this information to get an idea of how the electrician was thinking, and to define the extent of the problem. The last time I did this sort of thing, it took two men six hours; we had to move many pieces of furniture, many piles of books. In the end, we found the problem in a working receptacle that we had no reason to suspect was part of the circuit.
I once paid my local auto repair shop $150 to apply a piece of tape to a tiny wire nick. And I was glad to do it. This was after I'd already spent about 10 hours on the problem, trying to find a short in my wife's car. Luckily my efforts had turned it from an intermittent to a solid short, otherwise I'd probably have paid about twice as much.
If Tyranny and Oppression come to this land, it will be in the guise of fighting a foreign enemy. --James Madison
Not all devices are equal.
Consider for a moment that the volunteer did good work. Certainly their heart was in it as well as all work is inspected on a Habitat home. Back or side wired both meet UL standards and if it worked out of the box it was probably wired properly.
Consider the quality of goods, that is where I think the problem lies. Did anyone really think it was only marketing that separates the 35 cent bargain bin duplex outlet from the 10 dollar hospital grade?
Cheapie outlets connections are made of lesser gauge brass (if it isn't brass plated) and parts on the cheap devices are made less ruggedly.
If you've ever sat thru a (one of the the most booring) presentation on the construction differences of duplex recepticals you would have a firm grasp of the internal differences. Every manufacturer, Hubbel, Pass & Seymour, Eagle, you name them.. make at least three grades of device. Some make 5. There is no universal real "standard" for metal and construction grades. There are however MTBF standards on each grade.
I for one will never use less than Construction grade and will always opt for the Spec grade. The outlets in question are high use or tough use outlets I'd bet. Generally kitchen (coffee pot or tea kettle outlets), and the Vacuum cleaner "Favorite" outlet are the ones that get reamed by the plugs.
These houses aren't the Taj. They probably got a good value outlet. In many applications the works fine for incidental use. Frequent use locations ought to be of a better quality.
For your own experience try to plug and unplug a hospital grade outlet (10$ ea) you'll find the dimples on the plug do have a purpose. they interlock with the interior of the hospital grade outlet. It makes it much harder to accidentally unplug your heart lung machine.
Oh yea, I side wire. I like to see it. However I use Wago push on wire nuts so I believe in the push on connection (you can see in the nut with Wago)
I think you missed the point that this was not on a Habitat House, it was the home of one of his HH volunteers I believe. Other than that good advice/info.
http://forums.taunton.com/tp-breaktime/messages?msg=80397.21
Edited 10/23/2006 7:18 pm ET by rasconc
@@@ I for one will never use less than Construction grade and will always opt for the Spec grade. The outlets in question are high use or tough use outlets I'd bet. Generally kitchen (coffee pot or tea kettle outlets), and the Vacuum cleaner "Favorite" outlet are the ones that get reamed by the plugs.
Yes, go for the spec. I am happy I convinced SonInLaw to forego the Decora look and put the money into commercial spec backwire outlets. Had fun with that job. He almost got the garage wiring right. Needs a few more 240/50 drops.
If they are hemming, hawing and sucking their teeth, put the crap grade (residential) outlets when they get no action and spec grade in the kitchen, bath, shop and high use areas. There are table lamps that have not been unplugged in 10 years here. Crap grade will work there, if we must.
The ToolBear
"Never met a man who couldn't teach me something." Anon.
240 / 50 Amp? Ok 1 compressor with a massive motor, a welder, what else could you get the SIL to run with a 50 amp breaker?
Maybe you are running the RV up to the garage door and plugging in when you visit. ;-)
You know the time will come where we no longer have the exposed side wire screws on a duplex. I haven't seen them yet but almost all electrical product used in control panels is "touch safe" meaning inadvertent touching won't shock you. It started with 600 volt rated devices (ie 480 volts) and it has moved down to every terminal block, relay, and goofy sensor or control unit.
So why then do we continue to have exposed conductors the most frequently sold and touched electrical device? Because of tradition. How many people have illuminated a box or jolted their hand with 110 while working a box hot. Thousands... probably every day. The GFI took away the Darwinistic thinning of the herd in wet locations. However we all get shocked.
It won't kill most of us but the time is near when side wired devices will disappear.Jack of all trades and master of none - you got a problem with that?
@@ 240 / 50 Amp? Ok 1 compressor with a massive motor, a welder, what else could you get the SIL to run with a 50 amp breaker?
Future welder.
You can use a smaller breaker, depending on the load, but the wire is rated for 50A.
Of course, that thought about hooking up the motor home has a lot of merit <g>. My motorhome is an E150 van, but we can hope. I do with 120/30A on the boat, but a lot of the big powerboats want 240/50 and come with splitters to get it. The ToolBear
"Never met a man who couldn't teach me something." Anon.
I have seen the merit of having lots of circuits. Or have not seen because of too few circuits.
I have run in my shops (yea I made one in the cottage up north as well as the garage there) multiple 15 & 20 amp 240 circuits. But never that large. Although there is space for it in the load center. I suppose when the allure of making sawdust goes away I'll have to switch or add in metal.
But multiple 50 amp circuits...Dueling welders?
I guess you could make "weld sabers" and do a Luke Skywalker and Darth vader thing.
Jack of all trades and master of none - you got a problem with that?
@@ But multiple 50 amp circuits...Dueling welders?
Welder to port, air tower to starboard. Plan for the future. It's cheap when the walls are open. Besides, we need that RV station.
This is a 3 car garage with a granny unit behind and engineered to add a small apartment or storage loft full width along the back wall. Plus, there is a cupulo (sic) on the roof with a light to guide cars in.
Not like my condo garage where the power is so bad that the lights go into orange when I light up a table saw and a manly compressor won't even start. 12g feeders, from long way off. The ToolBear
"Never met a man who couldn't teach me something." Anon.
This being your friend's own home, I'd advise not even trying to do tricky tracing to isolate the problem. Instead, go for the whole house electrical tune-up. Fix this problem by also fixing everything that might potentially become a problem. Turn off all the power, open every box, make everything right. Start at first light on a Saturday morning. Map out circuits as you turn them back on. Bottom line, at home you want everything to work right, not just to find and fix one thing.
-- J.S.
@@@ Instead, go for the whole house electrical tune-up.
Good suggestion. Told him to learn to sidewire and start going through the place.
It could be any number of things, but we do get a nice amount of business from these tracts and backstab failure is a high probability. I've asked him to tell me what it was and where. The ToolBear
"Never met a man who couldn't teach me something." Anon.
> ... I've asked him to tell me what it was and where.
Ah, that's the rub with the whole house tune-up. Sure, you'll fix it. You'll also fix maybe a half dozen more things that were either worn out, or done wrong in the first place. But you may never know which one was actually the "it" that got you started on this job. ;-)
-- J.S.
Beyond Backstab -
Was called in on one today. We got the drywall off and found the most interesting things. The house is '60s and was wiring in proto Romex, to code. Since then a legacy of renovations = chamber of horrors -
The cover photo will be the rats nest of a wiring junction inside the drywall and foamed in place with something that probably burns real well. No box. Nada. Very DIYer. You can tell - they never leave any wire for the next guy - or themselves in this case.
Then there is the zip cord wired into an outlet, run up inside the DW (even drilled a hole or two) out the top and run in channel to the light in the center of the room.
Or the gas pipe run across the top of the roof.
We want a scope change. The ToolBear
"Never met a man who couldn't teach me something." Anon.