"Backstabbed" wiring: bad rap?
David Nebenzahl
"backstabbed" wiring is bad, evil, and always leads to failure--may not
be correct.
[To the perplexed, "backstabbed" means that instead of using screw
terminals to connect wires to devices such as outlets and switches, the
stripped (solid) wire is pushed into a connector that grabs the wire
inside the device. Very commonly used "in the field".]
The opinion one reads here most often is that this is an inferior wiring
method that must always be suspected when there are electrical problems,
that it should be avoided and that it should be corrected if found.
I'm not sure that's correct.
First of all, it is an approved, UL/CSA tested, and, most importantly,
code-approved (US building code) wiring method. If it was as all-fired
bad as folks here claim, why would it still be allowed? After all, the
building codes tend to err on the side of caution.
My own experience, as limited as it might be, has not shown backstabbed
connections to be the source of any trouble. I recently worked on a
house built in the 1960s in which all devices were backstabbed. I was
called to add a circuit, not to correct any problems. There was no
current problem with any device that I could see, nor was there any
history of any such problems.
I'd like to see some more evidence for the badness of backstabbed
connections. Everything I read here is either based on anecdotal
evidence, or just speculation and personal preference.
I will say that I personally don't like backstabbed connections; as
tempting as they are (a lot faster than
stripping/bending/screwing/crimping using screw connections), I prefer
the "old-school" method. But I do think they've gotten an unfairly bad
rap. Furthermore, I refrain from automatically correcting them
(replacing backstabbed connections with screwed ones) when I see them,
on the theory of "if it ain't broke, don't fix it", and I suggest this
to others. Especially newbies and DIYers; I think it's bad advice to
automatically suspect backstabbed connections as the source of a fault,
and to imply that they should all be ripped out and redone.
Let the brawling commence.
--
Found--the gene that causes belief in genetic determinism
bud--
>
> First of all, it is an approved, UL/CSA tested, and, most importantly,
> code-approved (US building code) wiring method. If it was as all-fired
> bad as folks here claim, why would it still be allowed? After all, the
> building codes tend to err on the side of caution.
They are allowed by the NEC because they are listed by UL.
UL used allow #12 wire in backstabs. Not anymore. Apparently their
original standard was flawed. (How about the #12 backstabs in use?)
Seems like several failures come up here in this rather limited forum
each year. IMHO they have minimal contact area, minimal clamping
pressure, and in slightly adverse environments are subject to chemical
deterioration. You will probably have no problem with backstabs. You
also probably won't need the pressure relief valve on your water heater.
I don't see any reason to take the chance.
--
bud--
Doug Miller
>I'm here to say that the conventional wisdom that one gets here--that
>"backstabbed" wiring is bad, evil, and always leads to failure--may not
>be correct.
>
>[To the perplexed, "backstabbed" means that instead of using screw
>terminals to connect wires to devices such as outlets and switches, the
>stripped (solid) wire is pushed into a connector that grabs the wire
>inside the device. Very commonly used "in the field".]
>
>The opinion one reads here most often is that this is an inferior wiring
>method that must always be suspected when there are electrical problems,
>that it should be avoided and that it should be corrected if found.
>
>I'm not sure that's correct.
>
>First of all, it is an approved, UL/CSA tested, and, most importantly,
>code-approved (US building code) wiring method. If it was as all-fired
>bad as folks here claim, why would it still be allowed? After all, the
>building codes tend to err on the side of caution.
Note that it is no longer approved for anything except AWG 14 conductors. Code
once permitted the use of AWG 12 conductors in backstabbed connections, as it
once permitted aluminum conductors in branch circuits and various other
practices and materials that have proven in experience to be less safe than
originally believed.
>
>My own experience, as limited as it might be, has not shown backstabbed
>connections to be the source of any trouble. I recently worked on a
>house built in the 1960s in which all devices were backstabbed. I was
>called to add a circuit, not to correct any problems. There was no
>current problem with any device that I could see, nor was there any
>history of any such problems.
If installed properly _and not disturbed_ it's unlikely they'll have much
problem. OTOH, if a backstabbed receptacle or switch is removed for any
reason, simply the act of moving the device can loosen the connections enough
to cause trouble.
>
>I'd like to see some more evidence for the badness of backstabbed
>connections. Everything I read here is either based on anecdotal
>evidence, or just speculation and personal preference.
I'd consider the de-listing of AWG 12 conductors to be sufficient evidence.
albee
wrote:
Solely anecdotal, but seems like quite a coincidence that I've had
problems with them staying connected, particularly in receptacles that
received frequent use (not taking out and working on, simply plugging
and unplugging of appliances). As a previous respondent said, if done
correctly and not disturbed... But if "anecdotally", merely using the
receptacle a lot in the manner intended is enough to cause such
disturbance, well, then it's not functioning as intended.
Now, I don't have non-backstabbed ones with which to compare them, but
I can't fathom that a non-backstabbed receptacle would have done the
same.
My amateur and anecdotal .02 worth.
RBM
"David Nebenzahl" <nob...@but.us.chickens> wrote in message
news:4a85b217$0$7446$8226...@news.adtechcomputers.com...
Turning a wire on a screw provides more surface area and more pressure on
the connection. An installer can see how well the connection is made, unlike
the blind connection of a backstab. I personally have used backstabs
thousands of times without any issues. I have the experience to feel when
the conductor is not fitting correctly in the blind clamp and needs to be
redone. The bulk of my business is electrical repair, and a large number of
open circuit problems turn out to be backstabbed outlets. I think some
manufacturers make better backstab connections than others, as there have
been times when I unscrew an outlet and pull it out of the box, leaving four
wires, unattached in the box
Stormin Mormon
we're all just random chance, and not evidence of a problem?
Scuse me while I go barf.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"David Nebenzahl" <nob...@but.us.chickens> wrote in message
news:4a85b217$0$7446$8226...@news.adtechcomputers.com...
Stormin Mormon
none with wrap around the screw types.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
"albee" <a...@a.com> wrote in message
news:lvkb85985oi6acitu...@4ax.com...
Don Phillipson
news:e666b$4a85c95f$cde8d592$14...@DIALUPUSA.NET...
> They are allowed by the NEC because they are listed by UL.
>
> UL used allow #12 wire in backstabs. Not anymore. Apparently their
> original standard was flawed. (How about the #12 backstabs in use?)
The practical point is that (in many jurisdictions) the Fire Safety Code
is the only part of the Building Code that is retroactive, i.e. when
the FSC is updated (some) property owners may be obligated to
retrofit (some) structures or fittings so that they comply with the
current code. (I do not know the American system, viz. whether
part or any of the NEC is also in the Fire Safety Code. But codes
are periodically revised, so code authorities may require this
in future.)
--
Don Phillipson
Carlsbad Springs
(Ottawa, Canada)
Pete C.
I've seen a number of problem push-wire / back-stabbed devices
personally, and they represent a sizable percentage of the number of
problem devices I've dealt with.
I have a house that happily has all 20A circuits with 12ga copper wire
(other than the larger dedicated circuits of course), and has many 12ga
push-wire connections that are no longer allowed.
I've not had specific failures of these connections as the devices seem
to be of reasonable quality, however where I have had opportunity to
replace these devices for other reasons (adding GFCIs or changing to
Decora style devices) I have seen evidence of less than optimum
push-wire connections, i.e. discolored area at the connection point from
heating.
The devices I have used for replacement have generally been the "spec
grade" variety and have had the much better clamp type back-wire
connections. These back-wire connections allow the same convenience of
inserting the stripped wire in a hole without the need to wrap around a
screw, but instead of relying on a feeble spring connection the wire is
captured between full size metal plates that clamp around it with screw
pressure, not a spring.
These back-wire devices also work nicely in my shop where I have
stranded wire pulled through conduit. Stranded wire doesn't work well
wrapped around screw terminals and not at all with the push-wire type
devices.
David Nebenzahl
> The devices I have used for replacement have generally been the "spec
> grade" variety and have had the much better clamp type back-wire
> connections. These back-wire connections allow the same convenience of
> inserting the stripped wire in a hole without the need to wrap around a
> screw, but instead of relying on a feeble spring connection the wire is
> captured between full size metal plates that clamp around it with screw
> pressure, not a spring.
You're talking about the kind of back-wire connections found on GFCI
outlets, right? To me, that's the best of both worlds: the convenience
and speed of back-wiring plus the positive connection offered by a screw
clamp. I think I'll start using those outlets instead of the el cheapo
Home Despot ones.
> These back-wire devices also work nicely in my shop where I have
> stranded wire pulled through conduit. Stranded wire doesn't work well
> wrapped around screw terminals and not at all with the push-wire type
> devices.
Being able to use stranded wire is definitely a plus.
David Nebenzahl
> You're talking about the kind of back-wire connections found on GFCI
> outlets, right? To me, that's the best of both worlds: the convenience
> and speed of back-wiring plus the positive connection offered by a screw
> clamp. I think I'll start using those outlets instead of the el cheapo
> Home Despot ones.
Follow-up to my own reply: Do those "spec-grade" outlets come in
non-Decora style? I generally don't like Decora outlets when installing
in older houses.
Nate Nagel
> On 8/14/2009 6:18 PM David Nebenzahl spake thus:
>
>> You're talking about the kind of back-wire connections found on GFCI
>> outlets, right? To me, that's the best of both worlds: the convenience
>> and speed of back-wiring plus the positive connection offered by a
>> screw clamp. I think I'll start using those outlets instead of the el
>> cheapo Home Despot ones.
>
> Follow-up to my own reply: Do those "spec-grade" outlets come in
> non-Decora style? I generally don't like Decora outlets when installing
> in older houses.
>
You can get "spec grade" outlets in the traditional style (I have
several boxes of them waiting for upstairs renovations) but not all of
them have back wire clamp type connections.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Pete C.
Yes, also I've yet to see a non Decora style GFCI, so for that you'd
have to resort to a horribly overpriced GFCI breaker to avoid the Decora
style, or else hide the Decora GFCI in a cabinet or similar and use non
Decora receptacles downstream.
Larry The Snake Guy
> First of all, it is an approved, UL/CSA tested, and, most importantly,
> code-approved (US building code) wiring method. If it was as all-fired
> bad as folks here claim, why would it still be allowed? After all, the
> building codes tend to err on the side of caution.
However, all kinds of unreliable crap is UL listed. A UL listing is a
pretty good indication that something probably won't kill you or burn
down your house, but says nothing at all about whether it will
function properly. Building codes put a little more emphasis on
function, but are also updated fairly regularly because things that
were once required are finally proven to be bad ideas.
Robert Green
<stuff snipped>
> >I'd like to see some more evidence for the badness of backstabbed
> >connections. Everything I read here is either based on anecdotal
> >evidence, or just speculation and personal preference.
>
> I'd consider the de-listing of AWG 12 conductors to be sufficient
evidence.
I've had two backstab failures, one near a disposal where the switch was
mounted on an outside wall and another on an inside wallswitch. I think the
thermal expansion/contraction plus the disposal vibration did the first one
in. Not sure why the second one failed. It's an indisputable fact, though,
that there's much more connection area in a screwed down wire than there is
with a pinch and grab kind of connector.
If the grabber is hard enough to bite into the copper to make a connection,
it's most likely strong enough to bite through it *eventually* if helped by
vibration, thermal forces and even the simple repeated toggling of the
connected switch. Once arcing starts, no matter how small, corrosion and
failure are likely to follow. More connection area in the screw connections
means less of a chance of arcing or pulling loose. Also, it's very much
harder to see a bad back stab than it is to see a wire not completely under
a screw. I'd agree that the delisted AWG 12 is a strong hint that anecdotal
evidence has added up to backstabbing being a bad idea, both with people and
electrical devices.
BW
Perry Aynum
and screw them down too much?
JIMMIE
Obviously you have never paid $300 for an electrician to find a bad
one or have the power in you livingroom go out when you have guest
coming over because of one. As far as I am concerned these things were
BROKE the day they were made. After my experience and expense with
them I made the decision to replace all the outlets and switches in my
home. When I started performing the replacements many of the wires
pulled out of the back of the switches and outlets when I was pulling
them out of the box. Most of the wires only required a firm tug to
pull them from the device and only a few actually required me to press
the release.
RBM
"JIMMIE" <JIMMIE...@YAHOO.COM> wrote in message
news:505bc2e9-40c4-4160...@s15g2000yqs.googlegroups.com...
Out of curiosity, do you know who the manufacturer was?
Andrew M. Saucci, Jr.
conductor is carefully trimmed, none of the conductor is actually exposed
inside the box. That can reduce the chance of a short, especially in a metal
box or where a bare grounding conductor is present. This would be a
particular advantage if screw terminals were not present at all (uncommon
these days).
Screw terminals can be dangerous too if they are over tightened or
under tightened, or if the conductor is poorly trimmed.
"David Nebenzahl" <nob...@but.us.chickens> wrote in message
news:4a85b217$0$7446$8226...@news.adtechcomputers.com...
stan
> "JIMMIE" <JIMMIEDEE...@YAHOO.COM> wrote in message
> coming over because of one. As far as I am concerned these things were
> BROKE the day they were made. After my experience and expense with
> them I made the decision to replace all the outlets and switches in my
> home. When I started performing the replacements many of the wires
> pulled out of the back of the switches and outlets when I was pulling
> them out of the box. Most of the wires only required a firm tug to
> pull them from the device and only a few actually required me to press
> the release.
>
>
> - Show quoted text -
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
nate
--
RBM
"stan" <tsan...@nf.sympatico.ca> wrote in message
news:56298c21-56a8-4e91...@p15g2000vbl.googlegroups.com...
OK, but do you have any particular manufacturer that has given you these
problems?
Robert Green
news:FMxhm.144020$zq1....@newsfe22.iad...
> Why take the risk? Is the extra two minutes required to pig-tail the ends
> and screw them down too much?
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
<stuff snipped>
<<When I started performing the replacements many of the wires
pulled out of the back of the switches and outlets when I was pulling
them out of the box. Most of the wires only required a firm tug to
pull them from the device and only a few actually required me to press
the release.>>
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
> 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!
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
<JIMMIE...@YAHOO.COM> wrote:
>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.
>
They should send people to jail for such shoddy work.
Robert Green
> On 8/15/2009 3:01 PM Robert Green spake thus:
<stuff snipped>
> 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.
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
<stuff snipped>
> 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.
<<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.>>
The same crew must have wired my house!
--
Bobby G.
bud--
> On Aug 14, 2:51 pm, David Nebenzahl <nob...@but.us.chickens> wrote:
>
>> First of all, it is an approved, UL/CSA tested, and, most importantly,
>> code-approved (US building code) wiring method. If it was as all-fired
>> bad as folks here claim, why would it still be allowed? After all, the
>> building codes tend to err on the side of caution.
>
> However, all kinds of unreliable crap is UL listed. A UL listing is a
> pretty good indication that something probably won't kill you or burn
> down your house, but says nothing at all about whether it will
> function properly.
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....
> Building codes put a little more emphasis on
> function, but are also updated fairly regularly because things that
> were once required are finally proven to be bad ideas.
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.
--
bud--
E Z Peaces
> 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.
>
>
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.
Twayne
> I'm here to say that the conventional wisdom that one gets here--that
> "backstabbed" wiring is bad, evil, and always leads to failure--may
> not be correct.
Agreed, but that doesn't make them preferable. They're used to save
money, mostly by electricianls.
> The opinion one reads here most often is that this is an inferior
> wiring method that must always be suspected when there are electrical
> problems, that it should be avoided and that it should be corrected
> if found.
> I'm not sure that's correct.
If it ain't broke, don't fix it. Backtabs are not a ticket to charing
more money for fixing what ain't broke.
>
> First of all, it is an approved, UL/CSA tested, and, most importantly,
> code-approved (US building code) wiring method. If it was as all-fired
> bad as folks here claim, why would it still be allowed? After all, the
> building codes tend to err on the side of caution.
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.
>
> Let the brawling commence.
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`
Smitty Two
"Twayne" <nob...@devnull.spamcop.net> wrote:
> It's a pretty stupid person that posts something only to see the
> outcomes of a few who will bit on the troll bait.
So how would you characterize those who bit?
David Nebenzahl
> "David Nebenzahl" <nob...@but.us.chickens> wrote in message
> news:4a85b217$0$7446$8226...@news.adtechcomputers.com
>
>> Let the brawling commence.
>
> It's a pretty stupid person that posts something only to see the
> outcomes of a few who will bit on the troll bait.
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.
--
bud--
Pete C.
What you stated, did not include pass criteria as *I stated*.
>
> 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.
You say that, but you did not post the actual UL test pass criteria.
>
> 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.
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.
>
>> 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.
>
> You say that, but you did not post the actual UL test pass criteria.
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.
>
>> 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.
>
> 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.
Then you are apparently not aware of a lot of UL tests.
--
bud--
Robert Green
news:9fbg85ppjci9ft060...@4ax.com...
> On Sun, 16 Aug 2009 00:53:45 -0400, "Robert Green"
> <robert_g...@yah00.com> wrote:
>
> >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.
> 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..
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.
Robert Green
news:h689q4$hhh$1...@news.eternal-september.org...
> Robert Green wrote:
>
> > 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.
> >
> >
> 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.
Me too. It's amazing how many bad ones I've come across where the twisting
was bad or they didn't even use close to the right sized wire nut. My
favorites, for 110VAC work, have little metal springs inside the nut. I
prefer them without the metal inside for low voltage wiring, especially when
I am not sure I am looking at the final configuration.
> 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.
There's no doubt they can be done well in the hands of an experienced user.
The problem is that in the hands of a beginner, they are usually not well
done, and in my experience, bad wire nutting has caused many more problems
than backstabbing. Bad nutting is also a lot harder to detect than someone
failing to get most of the wire under a screw.
> 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.
Hmm, I have a similar pair in the junk drawer that's also unsolderable. I
think I might give your approach a try.
--
Bobby G.
Andrew M. Saucci, Jr.
any other component in an electrical installation would otherwise fail or
need to be replaced. I don't have lots of faith in electrical tape for any
long-term role of importance and try to avoid using it for anything other
than holding a cable onto a snake.
"Nate Nagel" <njn...@roosters.net> wrote in message
news:h66hs...@news5.newsguy.com...
Metspitzer
a very long time.
Of course the foreman acts like he is giving you a kidney when he
gives you a roll.
The Daring Dufas
There are wire nuts and wing nuts and various designs in between.
The important feature is the design of the spring. The wire nut
had a round wire spring more suitable for stranded wire and the
wing nut had a square wire spring wound with the edges out so it
would cut into solid conductors making a better connection. The
designs have morphed over the years with manufactures claiming
suitability for both stranded and solid wires. I always look in
the cavity of the connector before using it to see how it's made
and/or if the darn spring is even there or corroded. Some of the
wire/wing nuts have expansion room inside for the spring to expand
which can make a better connection. I've grown fond of the newer
push in connectors which I've had very good luck with.
TDD
The Daring Dufas
> In my experience, electrical tape loses its stickiness long before
> any other component in an electrical installation would otherwise fail or
> need to be replaced. I don't have lots of faith in electrical tape for any
> long-term role of importance and try to avoid using it for anything other
> than holding a cable onto a snake.
>
It depends on the quality of the electrical tape. I can look at
a connection done with 3M 33+ tape and it will be just as good
as it was years before. We used to use the 3M tape for permanent
connections and cheap Jap wrap, now Chink wrap for wire pulling.
TDD
David Nebenzahl
> I've grown fond of the newer push in connectors which I've had very
> good luck with.
>
> http://tinyurl.com/nw5nt3
(or the real URL,
http://www.idealindustries.com/prodDetail.do?prodId=in-sure)
Interesting. One thing, though: it looks as if there's no way to pull
the wire out once it's in. Is that the case? If so, then these may be
great connectors to use when one is sure that one's work will never need
to be redone.
The Daring Dufas
> On 8/19/2009 10:41 PM The Daring Dufas spake thus:
>
>> I've grown fond of the newer push in connectors which I've had very
>> good luck with.
>>
>> http://tinyurl.com/nw5nt3
>
> (or the real URL,
> http://www.idealindustries.com/prodDetail.do?prodId=in-sure)
>
> Interesting. One thing, though: it looks as if there's no way to pull
> the wire out once it's in. Is that the case? If so, then these may be
> great connectors to use when one is sure that one's work will never need
> to be redone.
>
>
If you twist and pull at the same time you can pull the
wire out but it will not come loose on its own. It does
not seem to affect reuseability.
TDD
Pete C.
Again, that is incomplete criteria as it does not clearly specify the
pass / fail criteria. It is entirely possible for a device to be cycled
that many times, with the rated voltage and current applied and fail in
a way that presents no fire or shock hazard. and pass a safety test.
>
> >
> >> 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.
> >
> > You say that, but you did not post the actual UL test pass criteria.
>
> 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.
And again, anyone with minimal reading ability can see that what you
quoted is not a complete test specification and does not include the
pass / fail criteria.
>
> >
> >> 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.
> >
> > 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.
>
> Then you are apparently not aware of a lot of UL tests.
I've seen a number of them and none had anything to do with non safety
durability. A product could be a piece of crap and fail, as long as the
failure mode did not create a hazard that could lead to an insurance
claim.
bud--
The pass criteria, as I have said several times, is the switch survives
over 30,000 specified operations at rated voltage and at least rated
current and is functional at the end of the tests. The switch is not
allowed to fail during the 30,000 tests. A switch must "function
properly" to survive over 30,000 operations.
>>>> 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.
>>> You say that, but you did not post the actual UL test pass criteria.
>> 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.
>
> And again, anyone with minimal reading ability can see that what you
> quoted is not a complete test specification
What more do you want? From the information given I could construct
tests for the 30,000 operations. You want the exact language from UL?
Maybe you could look at your copy of UL30. The switch is not allowed to
fail during the 30,000 tests. There are other additional specs, but a
switch must "function properly" to survive over 30,000 operations. The
test is not just about "failing safely".
> and does not include the
> pass / fail criteria.
THE PASS CRITERIA, AS I HAVE SAID SEVERAL TIMES ALREADY, IS THE SWITCH
SURVIVES OVER 30,000 SPECIFIED OPERATIONS AT RATED VOLTAGE AND AT LEAST
RATED CURRENT AND IS FUNCTIONAL AT THE END OF THE TESTS.
Did it come through that time?
>>>> 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.
>>> 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.
>> Then you are apparently not aware of a lot of UL tests.
>
> I've seen a number of them and none had anything to do with non safety
> durability. A product could be a piece of crap and fail, as long as the
> failure mode did not create a hazard that could lead to an insurance
> claim.
As have said several times, a switch must survive all 30,000 specified
operations and be functional at the end to be UL listed. A piece of crap
is not likely to survive 30,000 operations and remain functional.
Or do you think a piece of crap can survive 30,000 operations and remain
functional?
What UL standards have you read?
Do you really think the electrical industry would allow, for example,
fuses and circuit breakers to open at random current levels, and only be
required to "fail safely"? That would be ridiculous. I have not read the
standard but I have seen references to required clearing times at 120%
and 200% of rated current rating. They certainly are tested at their
rated available fault current. I expect a lot more from fuses and
circuit breakers than that they just "fail safely".
--
bud--
Pete C.
You really have a reading comprehension issue. Again, what you have
quotes is not a complete test specification as would be used by any
reputable testing laboratory as it does not contain clearly defined pass
/ fail criteria.
Your diversion into circuit breakers doesn't help your case at all since
a circuit breakers are allowed to "soft fail" and trip at lower than
their rated current.
bud--
> quotes is not a complete test specification as would be used by any
> reputable testing laboratory as it does not contain clearly defined pass
> / fail criteria.
You have not explained how surviving 30,000 specified operations and
remaining functional is not a pass criteria.
> Your diversion into circuit breakers doesn't help your case at all since
> a circuit breakers are allowed to "soft fail" and trip at lower than
> their rated current.
Every manufacturer current-time trip curve shows an acceptable band. I
have no doubt UL specifies a similar band (ie max and min acceptable
clearing time at 200% of rated current). Tripping at too low a current
is also not permitted. You really think the electrical industry would
allow fuses/breakers to open at too low a current?
What UL standards have you read?
--
bud--
David Nebenzahl
> You really have a reading comprehension issue. Again, what you have
> quotes is not a complete test specification as would be used by any
> reputable testing laboratory as it does not contain clearly defined pass
> / fail criteria.
>
> Your diversion into circuit breakers doesn't help your case at all since
> a circuit breakers are allowed to "soft fail" and trip at lower than
> their rated current.
I've watched this argument devolve here for a while now. Although I
don't know what exactly UL uses for their test criteria, I find it very
hard to believe that they would approve devices that only "fail safely"
but that do not function properly at that point of failure (i.e.,
breakers that trip at significantly lower current than rated, switches
that no longer switch, etc.).
I think the burden of proof in this case is on *you*.
Pete C.
The burden of proof is on the person falsely claiming to be posting a UL
test standard. No reputable testing laboratory would attempt to test to
an incomplete test specification such as what mr bud has posted.
Remember was chartered to do product testing for the insurance industry,
not consumers. Insurers do not care at all about the quality,
functionality or value of a product, only if the product presents a
safety hazard that could lead to an insurance claim.
Circuit breakers are designed to and allowed to trip at a lower point as
they wear from multiple trips or age. They are not allowed to trip at a
higher than specified level. A "weak" breaker is a common failure and
does not present any safety hazard so it is not of any concert to
insurance underwriters nor to their testing lab.
bud--
> David Nebenzahl wrote:
>> On 8/21/2009 6:14 AM Pete C. spake thus:
>>
>>> You really have a reading comprehension issue. Again, what you have
>>> quotes is not a complete test specification as would be used by any
>>> reputable testing laboratory as it does not contain clearly defined pass
>>> / fail criteria.
>>>
>>> Your diversion into circuit breakers doesn't help your case at all since
>>> a circuit breakers are allowed to "soft fail" and trip at lower than
>>> their rated current.
>> I've watched this argument devolve here for a while now. Although I
>> don't know what exactly UL uses for their test criteria, I find it very
>> hard to believe that they would approve devices that only "fail safely"
>> but that do not function properly at that point of failure (i.e.,
>> breakers that trip at significantly lower current than rated, switches
>> that no longer switch, etc.).
>>
>> I think the burden of proof in this case is on *you*.
>
> The burden of proof is on the person falsely claiming to be posting a UL
> test standard. No reputable testing laboratory would attempt to test to
> an incomplete test specification such as what mr bud has posted.
Apparently Pete wants all 35 pages of UL20.
My original point was that, contrary to what had been stated, UL tests
for some products do establish whether a device will "function
properly". IMHO remaining functional after over 30,000 operations at or
above rated voltage and current demonstrates that.
I would have no trouble designing tests for the 30,100 operations which
I took from UL20. I would also have no problem determining if a switch
passed those tests. (The standard has additional details on these tests
and additional requirements.)
Pete has not said why he couldn't figure out the tests or whether a
switch passed.
(But that was not my intent anyway. I don't care if Pete can't figure
out how to make the tests.)
Pete is welcome to look at his copy and say what UL20 requires. I
eagerly wait.
> Remember was chartered to do product testing for the insurance industry,
> not consumers. Insurers do not care at all about the quality,
> functionality or value of a product, only if the product presents a
> safety hazard that could lead to an insurance claim.
The foregone conclusion results in denying the evidence?
Whatever the origin of UL it is, frankly, laughable to think that the
electrical industry would allow the present UL to list products used in
the electric power industry that have not been tested to "function
properly". Like for instance fuses, circuit breakers, motor starters,
switches, receptacles, GFCIs, AFCIs, ....
From the UL "white book":
"UL and its subsidiaries operate facilities throughout the world for the
testing, certification and quality assessment of products, systems and
services."
Note "quality assessment".
Take a particular category, fuses. A fuse could itself fail safely (or
operate but out of time spec) and still allow great damage, including
fire and explosion, downstream. It could also be the difference between
an electrician walking away from an event and severe injury or death
from arc flash. (I believe even insurers might be interested in that.)
> Circuit breakers are designed to and allowed to trip at a lower point as
> they wear from multiple trips or age. They are not allowed to trip at a
> higher than specified level. A "weak" breaker is a common failure and
> does not present any safety hazard so it is not of any concert to
> insurance underwriters nor to their testing lab.
Cite.
Still missing - the UL standards you have read that had nothing "to do
with non safety durability".
Also missing - the "proof" David asked for.
My source is UL20.
--
bud--
John Gilmer
> If you twist and pull at the same time you can pull the
> wire out but it will not come loose on its own. It does
> not seem to affect reuseability.
Some/most of them have a "slot" that will accept a very small flat blade
screwdriver. Push in the screwdrive and they release the wire.
Apparently the industry has solved the safety and reliability with the
"backstabing" outlets. Also there are connectors that use the same
"technology." They make them in a variety of "sizes" for wires sizes and
the number of conductors to be joined. They are "UL" approved so I guess
they are 'gud enuf.' I used the connectors in my attic and so far the
house hasn't burned down. But even the manufacturer says that they have
more resistance than your typical twisting wirenut connection. I guess,
however, it's within the range of acceptability.
BTW: "They" have finally made an "approved" splice for romex so that you
don't have to use a junction box when you can't "stretch" a cable when you
move a ceiling outlet or whatever. I pick up one on speculation but
haven't used it.
The Daring Dufas
BZZZIT, wrong item, you're describing the outlets, I was describing
the Ideal brand connectors. I have some other connectors that have
a little lever you flip up to insert/release each wire.
TDD
cl...@snyder.on.ca
It's approved today - but don't count on it being approved 5 years
from now. It was developed for the "mobile home" market - and that's
where it belongs (10 year lifespan, perhaps?)
Red Green
news:h6inml$2d4$1...@news.eternal-september.org:
Those are interesting. Never used them for 12/14 wire. Have seen on light
duty apps.