"Backstabbed" wiring: bad rap?

[stan]

Back stabbers just an inherently poorer design. But as wth aluminum wiring; not every installation will give trouble etc.

Again as with Al wiring; not every incorrect replacement (by say a homeowner who doesn't know any better) using a 'Copper Only' light switch will give trouble or overheat. Have seen them 'discovered' often with the exclamation "Hey this switch/outlet isn't Al compatible. Wonder how long that's been there?". Although it never actually caught fire in that particular usage; same with back stabbers. There must be very small wire contact areas in most back stabbers?

Another typical situation being if/when someone was 'finishing their own basement area'. And maybe hitched up extra copper wiring and receptacles etc. bought from a local hardware outlet. On the basis of my uncle showed me how to do it!

And; "Hey Madge. Into XYZ store, pick me up a half dozen duplex outlets will ya! Them ivory ones; OK?".

I think have seen back-stab outlets that also had screws on the side and 99% certain, doing work mainly for self, would have used the screws. With relatively low wattage loads on duplex outlets in many living areas ) typically a few lamps maybe a domestic TV or 'stereo' there presumably would be less chance of problems with back stabbers anyway?

Anywhere there can be 'heavy' wattage loads, and/or frequent unplugging etc. such as kitchen outlets, around work benches always best to use high quality duplex and other outlets.

Recently replaced two well used outlets under work bench that were first installed in the late 1970s. One of them was cracked; don't know how, but glad we found it! Also when not in use 'all' tool power is turned off in work shop by one main individually fused 115/230 volt switch. Also found, to my surprise a single very old style duplex outlet that must have added for a small tube radio (about 30 watts) on a small high shelf also off the main workshop feed. Not a backstabber but so old as to have a weird pattern cover plate. Looks like the whole thing, metal box and all, might have come out of an old farmhouse or barn!

[Nate Nagel]

just wrap a turn of electrical tape around the recep in a tight box

nate

Andrew M. Saucci, Jr. wrote:

[RBM]

Back stabbers just an inherently poorer design. But as wth aluminum wiring; not every installation will give trouble etc.

Again as with Al wiring; not every incorrect replacement (by say a homeowner who doesn't know any better) using a 'Copper Only' light switch will give trouble or overheat. Have seen them 'discovered' often with the exclamation "Hey this switch/outlet isn't Al compatible. Wonder how long that's been there?". Although it never actually caught fire in that particular usage; same with back stabbers. There must be very small wire contact areas in most back stabbers?

Another typical situation being if/when someone was 'finishing their own basement area'. And maybe hitched up extra copper wiring and receptacles etc. bought from a local hardware outlet. On the basis of my uncle showed me how to do it!

And; "Hey Madge. Into XYZ store, pick me up a half dozen duplex outlets will ya! Them ivory ones; OK?".

I think have seen back-stab outlets that also had screws on the side and 99% certain, doing work mainly for self, would have used the screws. With relatively low wattage loads on duplex outlets in many living areas ) typically a few lamps maybe a domestic TV or 'stereo' there presumably would be less chance of problems with back stabbers anyway?

Anywhere there can be 'heavy' wattage loads, and/or frequent unplugging etc. such as kitchen outlets, around work benches always best to use high quality duplex and other outlets.

Recently replaced two well used outlets under work bench that were first installed in the late 1970s. One of them was cracked; don't know how, but glad we found it! Also when not in use 'all' tool power is turned off in work shop by one main individually fused 115/230 volt switch. Also found, to my surprise a single very old style duplex outlet that must have added for a small tube radio (about 30 watts) on a small high shelf also off the main workshop feed. Not a backstabber but so old as to have a weird pattern cover plate. Looks like the whole thing, metal box and all, might have come out of an old farmhouse or barn!

OK, but do you have any particular manufacturer that has given you these problems?

[Robert Green]

I agree. Why take the risk? But have you ever see a klutzy newbie try to bend a wire loop or screw down a solid copper wire? I'd say fully half the rank newbie work is not fully under the screw or formed into the proper curve and is destined to work loose. I'd say that reason and the "time is money" contracting rule is why backstabbing got started.

Never on my own work, not after trying to trace that damn intermittent in the backstabbed disposal switch, but I can see why some contractors do it. I think it's one of the things that separates the pros from the tyros. Just like lining up the two screws on a switch faceplate so they are in the same orientation. (-: I grew up next door to an old-world craftsman of an electrician who helped wire the NYC subway system. His work is still in use today. Quality work lasts. But I digress.

A much more critical newbie error is to cut into the wire while stripping it which is a risk for either sort of connection method, screw or backstab. Ah, for a nickle for every time I've seen or accidentally done that myself!

Newbies and wire nuts don't mix well, either. Stripped end of wires too long, too short, wrong size nut, wrong mix of wires, twist not twisted enough. There's no end to sad tales with wire nuts in the hands of the inexperienced. My favorite is three wires under one nut with a virtually untwisted center wire that pulls right out on the first tug. I am much more concerned with bad wire nutting than with backstabbing.

-- Bobby G.

[Robert Green]

Easy to believe. If they were made offshore, there's no way to tell whether someone dumped the metallurgical equivalent of melamine into the metal they used to make the springs that clip the wire in. Metal can change properties over time with corrosion and stresses of various kinds. A loss of springiness is easy to imagine. As I recall the bum switch I had was the same. The backstabbed wires came out without pressing in the release. That CAN'T be good!

-- Bobby G.

[JIMMIE]

I found problems with wire nuts also in my lighting. On several ovehead light the wires just pulled out of the nuts when I pulled them down for inspection. I also found 6 lights, two in the bathrooms and four outside that did not have J boxes They were just screwed to the wall withe the wirenuts tucked inside the wall. None of the light fixtures were grounded. I later heard that the electrician only did the electrical rough-in. The unskilled labour installed the lights and outlets.

Jimmie

[David Nebenzahl]

On 8/15/2009 3:01 PM Robert Green spake thus:

Since you mention it, this is certainly a potential source of frustration to anyone doing wiring, newbie or not.

I bought myself a really nice automatic wire stripper--the kind that strips the wire in one squeeze, made by GB (Gardner Bender). Very well-made tool, very useful. Except that it doesn't always strip the wire correctly. I actually returned the first one I bought because of this problem, but it seems to be due to inconsistencies in actual wire diameters between cables that are nominally identical (#12, for example). So sometimes it strips perfectly, but other times I have to go to the next-smaller set of teeth, which can nick the wire if you're not careful.

When this tool works correctly it's an absolute pleasure to use: put the wire into the right set of teeth, squeeze, and the insulation is ejected like a shell casing.

[Metspitzer]

They should send people to jail for such shoddy work.

[Robert Green]

I had a cable stripper that was set perfectly to strip RG6QS for the compression connectors I use. It was perfect but a buddy spun it backwards, the blades popped out and all the king's horses and all the king's men couldn't put it back together. A good cable stripper is a very helpful tool, indeed, and can save tedious hours of hand work on a big job.

I bought a pair of Klein Romex strippers that cut it like butter and removes the outer wrap and the inner insulation on both conductors in one operation. Works great when new, not sure how it will work after wiring up a house and the blades get duller. As you point out, though, not every roll of wire is created equally or exactly to spec so I check every new roll to see if it's nicking the wire.

I replaced all the switches in my house with X-10 remotely controlled ones and far too many of the switch wires broke right where the insulation had been stripped and the wire nicked. One wire broke off so short I had to pull the box and gouge out the plaster to repair it. Of course that meant redoing the attendant plastering and painting. Yuck.

-- Bobby G.

[Robert Green]

The same crew must have wired my house!

-- Bobby G.

[bud--]

By coincidence I have the UL standard [15 years old] for "Snap Switches". For AC-only switches (which is what are commonly used) the switch must pass all the following at rated voltage:

- 10,000 operations at rated current

- 10,000 operations at rated current and power factor around 0.8

- 10,000 operations at rated current controlling incandescent loads [high inrush current]

- 100 operations at 4.8x rated current and power factor around 0.5

IMHO this is testing for whether the switch will "function properly".

My recollection is receptacle tests are similarly rigorous and include plugging and unplugging and operating for a periods at significantly above rated current.

I think most of us would be very unhappy if fuses or circuit breakers that are UL listed did not "function properly".

For devices like TVs, it is not possible (or desirable) for UL to determine if the device is actually useful. The test is whether the device will "kill you or burn down your house".

Standards may not be perfect. They weren't for #12 backstabs, old technology #12 and #10 aluminum wire, or devices originally used with that wire. And standards for GFCIs have changed quite a bit.

IMHO standards are not adequate for #14 backstabs - maybe if they were limited to #20 wire or smaller....

The NEC has very few equipment construction requirements and I can't think of any performance requirements.

The 'prime directive' is that "equipment required or permitted by this Code shall be acceptable only if approved".

"Approved" is "acceptable to the authority having jurisdiction."

The NEC generally has only a few rather general guidelines on what should be acceptable. "Authorities" generally accept equipment that is "listed" or "labeled", but it is up to the "authorities".

The NEC did not eliminate #12 backstabs or change requirements for #12 and #10 aluminum wiring.

[E Z Peaces]

The connection would probably have been strong if all three wires had been virtually untwisted. When John Blomstrand filed to patent the wire nut in 1950, that was his intent. If wires are straight and solid and of equal gage with even ends, I suppose the threads of a wire nut should engage every wire in a bundle of as many as six, mashing them together with no wiggle room.

Thirty years ago it was apparently common for electricians to use wire nuts badly, twisting wires together clockwise before twisting on the connector clockwise, then hoping tape would hold everything in place. I've redone many.

I love wire nuts even for conductors of dissimilar gages and stranded conductors, each of which may make it trickier to use wire nuts. Nearly

40 years ago, I installed a fairing on my motorcycle, which entailed splicing splicing the six stranded conductors of the fairing's wiring harness to six stranded conductors on my motorcycle. I used wire nuts. I've ridden more than 100,000 miles since then and never parked indoors, and those connections have never needed attention.

Pruning shrubs five years ago, I snipped the cord of my expensive headphones. The copper strands were too fine to solder, so I taped the three conductors with masking tape and used a wire nut to apply pressure and provide mechanical strength. Those phones still work fine.

[gfretwell]

If that is the stack of metal plates with a couple razor blades in it, there should be a tool included to set the blade depth. It is a metal rod with fly cuts at the proper depth. Clamp it in the stripper, set the blades to just touch the rod and tighten up the screws holding the stack together..

[Twayne]

Agreed, but that doesn't make them preferable. They're used to save money, mostly by electricianls.

If it ain't broke, don't fix it. Backtabs are not a ticket to charing more money for fixing what ain't broke.

All irrelevent: Those are safety standards and the only thing they test for is that they meet their specs, won't create a shock hazard or a fire hazard. They could care less if they stopped working and sometign opened 3 hours after installation. As long as there's no safety hazard, they will be passed.

It's a pretty stupid person that posts something only to see the outcomes of a few who will bit on the troll bait.

Twayne`

[David Nebenzahl]

On 8/16/2009 10:25 AM Twayne spake thus:

Would you have felt differently if I had put a smiley face after that statement?

Hint: I don't do smiley faces.

[Pete C.]

The standard you quote may or may not test whether the device will "function properly" as you did not include the pass / fail standards. If the fail standard is "fire" and the pass standard is "no fire", then the switch could well stop functioning "properly" well under the cycle count limit and still pass the test.

[bud--]

The "pass standard", _as I stated_, is that "the switch must pass all the following". The switch must still work after over 30,000 operations. And that is only part of the standard.

UL standards, as they apply to wiring components (switches, receptacles, fuses, circuit breakers, panels, wire, motor starters, wire nuts, ...), is that those products will "function properly", not just that they will fail safely.

For some other equipment, like TVs and industrial control panels, it is not practical or desirable to test if the device functions as intended, and the test is that it fails safely. That may involve using "listed" or "recognized" component parts that are tested to "function properly" as above.

[Pete C.]

What you stated, did not include pass criteria as *I stated*.

You say that, but you did not post the actual UL test pass criteria.

All UL tests that I'm aware of test only for safety, not durability, reliability, or functionality. If the device does not cause a hazardous condition that might result in an insurance claim (note it is

*Underwriters* Laboratories, not *Consumers* Laboratories), it passes.

[bud--]

My original post said "the switch must pass all the following at rated voltage". I quoted a portion of that in my last post. With minimal reading ability anyone should be able to determine the UL test requires a switch to survive over 30,000 operations at rated voltage and at least rated current.

With minimal reading ability anyone should be able to determine switches need to pass all of the following:

- 10,000 operations at rated current

- 10,000 operations at rated current and power factor around 0.8

- 10,000 operations at rated current controlling incandescent loads [high inrush current]

- 100 operations at 4.8x rated current and power factor around 0.5

That is what my original post said and the requirements were taken from the UL standard.

Then you are apparently not aware of a lot of UL tests.

[Robert Green]

If only it went back together and stayed together. Once it threw the blades, it didn't go back together worth a damn. It's very possible that some tiny wire springs popped out when it "barfed its blades." I've not be able to find a similar, three-bladed replacement but I keep looking. ); Thanks for your input.

-- Bobby G.