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wire nuts

E

E Z Peaces

Jan 1, 1970
0
Before 1975 I preferred to splice with solder. Then I came to love wire
nuts: easier to use, less to go wrong, reliable, usable where I couldn't
get both hands, and undoable without tools.

About 1982 I discovered the B-cap. Apparently the only advantage was
that the spring would expand more than some designs. It meant one size
would work for most connections I needed, it seemed to grip more
securely, and it was easier to get it to encompass all the ends of my
conductors.

As I clipped some shrubs, I snipped the cord of my expensive headphones.
Those silky copper strands looked impossible to splice. I used
masking tape to splice each of the three conductors, then screwed a
B-cap over the whole thing. It has been trouble-free for years. I'd
call the B-cap a versatile wire nut.

I think they came in B1, B2, and B4. They were on Ideal's website a
month ago. Now I don't see them. Has the B-cap been made obsolete?

A neighbor prefers Scotchloks and crimped butt splices for his big rig.
Most of his electrical problems seem to come from old Scotchlok
connections, and they can be tricky to use even with two hands.

Over the years, I've often had wires pull loose after I crimped a butt
splice. On my neighbor's truck, mechanically strong butt splices may
feel warm in use.

Are Scotchlocks or butt splices or other methods somehow superior to a
good wire nut properly applied?
 
S

Son of a Sea Cook

Jan 1, 1970
0
Before 1975 I preferred to splice with solder. Then I came to love wire
nuts: easier to use, less to go wrong, reliable, usable where I couldn't
get both hands, and undoable without tools.

About 1982 I discovered the B-cap. Apparently the only advantage was
that the spring would expand more than some designs. It meant one size
would work for most connections I needed, it seemed to grip more
securely, and it was easier to get it to encompass all the ends of my
conductors.

As I clipped some shrubs, I snipped the cord of my expensive headphones.
Those silky copper strands looked impossible to splice. I used
masking tape to splice each of the three conductors, then screwed a
B-cap over the whole thing. It has been trouble-free for years. I'd
call the B-cap a versatile wire nut.

I think they came in B1, B2, and B4. They were on Ideal's website a
month ago. Now I don't see them. Has the B-cap been made obsolete?

A neighbor prefers Scotchloks and crimped butt splices for his big rig.
Most of his electrical problems seem to come from old Scotchlok
connections, and they can be tricky to use even with two hands.

Over the years, I've often had wires pull loose after I crimped a butt
splice. On my neighbor's truck, mechanically strong butt splices may
feel warm in use.

Are Scotchlocks or butt splices or other methods somehow superior to a
good wire nut properly applied?


I think that you may merely be nuts over wires. Nice title. :)

Anyway, good luck finding what you are after.
 
T

Tzortzakakis Dimitrios

Jan 1, 1970
0
? "E Z Peaces said:
Before 1975 I preferred to splice with solder. Then I came to love wire
nuts: easier to use, less to go wrong, reliable, usable where I couldn't
get both hands, and undoable without tools.

About 1982 I discovered the B-cap. Apparently the only advantage was that
the spring would expand more than some designs. It meant one size would
work for most connections I needed, it seemed to grip more securely, and
it was easier to get it to encompass all the ends of my conductors.

As I clipped some shrubs, I snipped the cord of my expensive headphones.
Those silky copper strands looked impossible to splice. I used masking
tape to splice each of the three conductors, then screwed a B-cap over the
whole thing. It has been trouble-free for years. I'd call the B-cap a
versatile wire nut.

I think they came in B1, B2, and B4. They were on Ideal's website a month
ago. Now I don't see them. Has the B-cap been made obsolete?

A neighbor prefers Scotchloks and crimped butt splices for his big rig.
Most of his electrical problems seem to come from old Scotchlok
connections, and they can be tricky to use even with two hands.

Over the years, I've often had wires pull loose after I crimped a butt
splice. On my neighbor's truck, mechanically strong butt splices may feel
warm in use.

Are Scotchlocks or butt splices or other methods somehow superior to a
good wire nut properly applied?
The title should have been wire soup to nuts:)
Anyway, in EU (Greece) we ue exclusively wire nuts, never heard of the other
things you use. I doubt whether they ever used solder, though.
 
T

TheJoker

Jan 1, 1970
0
IT MAY NOT SEEM NECESARY AT TIME BUT THE TRICK IS TOO SPLICE AND TWIST
THEM TIGHTLY TOGETHER BEFORE YOU CAP THEM WITH A BUTT SPLCE OR WIRE
NUT

I AM PROTEUS


In your case, the trick would be to open your skull cavity, and cut the
three nerves between the two halves of your brain (if they are still
there, and if you have them to begin with)(your behavior makes it
impossible to tell).

Then, you would be less spliced, and less twisted, tightly or
otherwise.

Then the electro-shock sessions could start.

Bwuahahahahahahaahahahahaha!
 
A

Andrew Gabriel

Jan 1, 1970
0
How long have they been used exclusively in EU?

They were never popular or common in the UK, and were
completely displaced by more reliable mains connectors
by the late 1930's. They were called "Screwits" here,
not wirenuts. They were in effect made illegal in 1960's,
as they'd never got British Standards approval, which
became mandatory for wiring accessories at that point.
However, they were long gone before then anyway.

They continued to be used for very low voltages (e.g.
door bells, radio receiving aerials) through to the 1950's.

Just for confusion, there are a couple of connectors
here which look similar and can be confused with wirenuts.
The first is a crimp in which the metal insert is crushed
onto the conductors through the plastic casing. The second
(no longer used in exactly the same form) was a bit like a
wirenut, but had a couple of grub screws in the side to
clamp the conductors in the internal brass insert, and was
very commonly used in 1920's through to 1950's.
These were the forerunner of the current chocolate block
connectors, which have the same brass inserts and are
very commonly used today.
 
J

James Sweet

Jan 1, 1970
0
They were never popular or common in the UK, and were
completely displaced by more reliable mains connectors
by the late 1930's. They were called "Screwits" here,
not wirenuts. They were in effect made illegal in 1960's,
as they'd never got British Standards approval, which
became mandatory for wiring accessories at that point.
However, they were long gone before then anyway.


I've had some quite extensive discussions on this topic with an EE
friend in the UK, and after sending him a few of our wire nuts, he says
they're much better than those available in the UK. As for which forms a
better connection, the UK style terminals or US style wire nuts, it's
pretty much a toss up, both are very reliable. Installed correctly, the
wire will usually break under tension before the wire nut will come off.
It's extremely rare for them to cause any trouble at all.
 
A

Andrew Gabriel

Jan 1, 1970
0
I've had some quite extensive discussions on this topic with an EE
friend in the UK, and after sending him a few of our wire nuts, he says
they're much better than those available in the UK. As for which forms a

In which case your friend was clueless about requirements for
cable conductor termination in the UK and how they came about.
better connection, the UK style terminals or US style wire nuts, it's
pretty much a toss up, both are very reliable. Installed correctly, the
wire will usually break under tension before the wire nut will come off.
It's extremely rare for them to cause any trouble at all.

That's not what the stats say about them.
 
E

E Z Peaces

Jan 1, 1970
0
Andrew said:
They were never popular or common in the UK, and were
completely displaced by more reliable mains connectors
by the late 1930's. They were called "Screwits" here,
not wirenuts. They were in effect made illegal in 1960's,
as they'd never got British Standards approval, which
became mandatory for wiring accessories at that point.
However, they were long gone before then anyway.
I can imagine voting to outlaw them.

I was an electronics technician in the Coast Guard. Whatever method I
used, it was important to test my workmanship by tugging each conductor.

I didn't use wire nuts in my duties but did use them to connect lighting
as the manufacturer instructed when I installed a fairing on my
motorcycle. A reliable headlight connection was a matter of life or
death, and a short could have been disastrous in a system without fuses.
In 36 years of vibration and moisture, I've had no trouble with those
connections.

In 1976, the vestry at my church asked me to rewire a dozen old lights
that hung on chains in the nave. The old wiring used solid conductors
with twisted connections wrapped in cloth tape. The connections had
worked for decades and were mechanically sound when I removed the tape.
Workmanship counts.

The box of wire nuts said, "No need to twist wires." I found that the
finely stranded conductors I was using would twist CW as I screwed on a
wire nut. As a result, I would feel movement when I tugged. With this
kind of conductor, if I twisted CCW before applying the wire nut, its
threads would get a better grip on the conductors.

After I agreed to do the job, I was told the junior warden's sons would
assist me. I was uneasy. On ladders, we couldn't work together. I'd
have to trust their workmanship.

I explained the importance of testing a connection by tugging the
conductors. I told them I'd found that in this case a wire nut would
hold better if the conductors were twisted CCW.

They had wired several lights when the senior warden dropped in. They
complained that I had told them to twist the conductors CCW. He was not
an electrician. He sold lumber. He told them I was wrong and they
should twist CW. For years, my responsibilities had included reliable
connections. I was supposed to be in charge, but neither my assistants
nor the warden consulted me.

Apparently the boys had disregarded my instructions and now they wanted
the warden's support. If they thought their method was okay, they had
not been testing their connections. Such indifferent workmanship would
explain why it was common to tape over wire nuts.

If connectors had to be foolproof, I would have outlawed wire nuts.
However, this was not the Coast Guard or a motorcycle. Nobody's life
depended on the connections. They were in proper enclosures and the
circuits had breakers. I suppose that's why Underwriters' Laboratories
approved wire nuts.

My BIL once worked for an electrician who showed him how to twist
conductors CW with pliers, snip the ends even, screw on a wire nut, and
tape. He rewired his house as he remodeled. Then he asked me to make
some improvements.

I found his connections mechanically sound when there were only two
conductors. With four or five, I felt movement. I found that if I laid
the ends parallel without twisting, I could get solid connections; but
it was hard to get the ends of several conductors even and sometimes it
would take more than one try to get a mechanically sound connection. In
these cases, modern live-spring wire nuts were much more foolproof.
 
R

Rich.

Jan 1, 1970
0
E Z Peaces said:
They had wired several lights when the senior warden dropped in. They
complained that I had told them to twist the conductors CCW. He was not
an electrician. He sold lumber. He told them I was wrong and they should
twist CW. For years, my responsibilities had included reliable
connections. I was supposed to be in charge, but neither my assistants
nor the warden consulted me.

I find it disturbing that a guy who sell lumber knew better than you how to
make a splice correctly. The problem with your method is that the expansion
and contraction over time allows the wire nuts to loosen and they fall off
when someone moves the splice around. Wire nuts are UL approved only when
the splice is twisted CW for a reason.
 
M

Mycelium

Jan 1, 1970
0
I find it disturbing that a guy who sell lumber knew better than you how to
make a splice correctly. The problem with your method is that the expansion
and contraction over time allows the wire nuts to loosen and they fall off
when someone moves the splice around. Wire nuts are UL approved only when
the splice is twisted CW for a reason.


The effect is known as "bird caged". CCW twisting in cable assemblies
causes problems as well, and I hate having to explain to a contract
vendor their own job of the details of making a simple cable harness.
 
E

E Z Peaces

Jan 1, 1970
0
Rich. said:
I find it disturbing that a guy who sell lumber knew better than you how
to make a splice correctly. The problem with your method is that the
expansion and contraction over time allows the wire nuts to loosen and
they fall off when someone moves the splice around. Wire nuts are UL
approved only when the splice is twisted CW for a reason.

Can you cite that?

Every box I've bought says "no need to twist" or instructs the user to
hold the ends straight. Do these manufacturers ignore the UL?

None of my splices end up with a CCW twist. The stranded conductors
with the thinnest, most flexible strands are the ones I start with a CCW
twist (less than one turn) and they end up with biggest CW twist. In
twisting from CCW to CW, they pass through being straight, and that's
when the tapered threads can best squeeze them all together.

If I intend to open and remake a splice of very flexible conductors,
I'll tin the ends and lay them straight as the instructions say. I've
read about a third method. Instead of tinning, simply twist each
conductor for stiffness, then lay them straight as the instructions say.
I haven't had a chance to try it because it has been years since I
spliced conductors with fine strands.

If the UL says conductors must first be twisted CW, I wonder why the
electrician who taught my BIL to do that also taught him to apply tape.
I often found insecure connections when I removed the tape. If I
redid such a splice according to the manufacturer's instructions, no
conductor would budge when I tugged. A good tight mechanical connection
is less likely to heat up.

When and where did the UL say conductors must first be twisted CW?
 
E

E Z Peaces

Jan 1, 1970
0
Mycelium said:
The effect is known as "bird caged". CCW twisting in cable assemblies
causes problems as well, and I hate having to explain to a contract
vendor their own job of the details of making a simple cable harness.

Where can I read about this effect?

With straight conductors and a properly sized wire nut, tightening will
cause a gradual increase in friction like a pipe with tapered threads.
To me, that says the contact area between conductors is increasing (to
handle current better) and the wire nut is less likely to come unscrewed.

I've never liked the feel if, contrary to manufacturer's instructions, I
start with a CW twist on the conductors. I don't get that gradual
increase of friction.

The strands of ordinary stranded wire such as would be used for
automotive lighting, are stiff enough for me to lay the conductors
straight, like solid conductors.

Lamp cord may be so flexible that friction from turning a wire nut can
twist it to the point where it bunches up; the twisting of the
conductors increases the diameter before the wire nut can compress them.
In order to be threaded inconspicuously along the chains, the wire for
the church lights was flexible like that.

I was like the boys in that intuition told me to stiffen the conductors
by twisting slightly CW. I tried it several times and it was
unsatisfactory. That pretwist caused the bunching to start sooner.
Instead of increasing friction, I'd feel wire twist and the nut jam.
Tugging the conductors would help untwist the copper, reducing the
diameter and causing one or both conductors to come loose.

That's when I tried half a turn CCW. It stiffened the conductors but
shortened them only about 1%. When I did it that way, I felt the wire
nut tighten gradually as with solid conductors, and my connections
resisted tugging. I believe it works by letting the clamping action of
the wire nut get a little ahead of the expansion caused by the CW twisting.
 
E

E Z Peaces

Jan 1, 1970
0
Rich. said:
I find it disturbing that a guy who sell lumber knew better than you how
to make a splice correctly. The problem with your method is that the
expansion and contraction over time allows the wire nuts to loosen and
they fall off when someone moves the splice around. Wire nuts are UL
approved only when the splice is twisted CW for a reason.

I've been trying to find out about a UL requirement for pretwisting.
Pat Porzio is an electrician who says,

"For a connector to be UL-listed, it must make a firm splice without
pretwisting."

http://www.popularmechanics.com/home_journal/how_to/4206309.html
 
R

Rheilly Phoull

Jan 1, 1970
0
Stuart said:
Well, they might be used in Greece but certainly not in the UK.
I guess in most countries the experience of the trades person counts for a
lot, unfortunately this seems to be a 'fast track area' these days.

Cheers .......... Rheilly P
 
A

Archimedes' Lever

Jan 1, 1970
0
Every box I've bought says "no need to twist" or instructs the user to
hold the ends straight. Do these manufacturers ignore the UL?


Generally, the effect of twisting one on causes a CW twist in the bunch
being grappled.
 
R

Rich.

Jan 1, 1970
0
E Z Peaces said:
I've been trying to find out about a UL requirement for pretwisting. Pat
Porzio is an electrician who says,

"For a connector to be UL-listed, it must make a firm splice without
pretwisting."

http://www.popularmechanics.com/home_journal/how_to/4206309.html

I never said anything about pretwisting, you did. I said that wire nuts are
UL approved for CW twists, as opposed to your CCW twist application. When an
untwisted splice is inserted into a wire nut and the wire nut is twisted,
the splice ends up with some degree of a CW twist to it. So at no point
during the installation of the wire nut does the splice develop a CCW twist.

Even this article you posted the link to states, "Next, hold the wires
firmly together with the stripped ends parallel (step 1). Press the
connector over the wires. There should be no exposed conductor (step 2).
Twist the connector clockwise and stop when the splice is tight (step 3)."

Your own article states to start with the wires parallel, not a CCW twist.
 
J

James Sweet

Jan 1, 1970
0
Andrew said:
In which case your friend was clueless about requirements for
cable conductor termination in the UK and how they came about.


That's not what the stats say about them.


What stats? What sort of wire nuts? Cite source.

I have here a nice assortment of UK terminal strips and other hardware,
it works well and I like the terminal strips for wiring stuff up in
equipment I build and various temporary setups.

I also have US style wire nuts as they're the standard method for
joining wires here. There are millions and millions of them in daily use
throughout the country, and I stand by my assertion that properly
installed, they form a very strong, dependable connection. The tapered
spring insert cuts slightly into the solid copper conductors and twists
them together as the nut is applied. Again, these are good quality name
brand parts I use.

I cannot speak for the wire nuts available in the UK as I've never had
any, but according to my only source on this, they are not particularly
good, and have never been popular.
 
E

E Z Peaces

Jan 1, 1970
0
Rich. said:
I never said anything about pretwisting, you did. I said that wire nuts
are UL approved for CW twists, as opposed to your CCW twist application.
When an untwisted splice is inserted into a wire nut and the wire nut is
twisted, the splice ends up with some degree of a CW twist to it. So at
no point during the installation of the wire nut does the splice develop
a CCW twist.

Where does the UL specify twisting conductors clockwise? Don't they
test connections after following manufacturers' instructions? The
instructions I've seen don't say the conductors must be twisted before
or during application of the connector.

In his patent drawings, the inventor of the wire nut showed no twisting
of conductors before or after application of the connector. It was a
live-spring device, my favorite type. The spring conformed around the
conductors, squeezing like a boa constrictor with several convolutions.
In my experience, if I use a live-spring wire nut with large, solid
conductors (such as #12 or #10 with a nut sized for #10 maximum), it
will probably tighten fully without twisting the conductors.

In my experience, fully tightening a rigid wire nut will twist the
conductors. Twisting expands the diameter of the bundle of conductors
to wedge against the tapered threads. In my experience, a rigid wire
nut will squeeze more tightly and be more securely affixed if it becomes
tight with only a little twisting of the conductors.

I think I understand why. If conductors are twisted slightly, so that
they are nearly parallel to the axis of the nut, twisting 1/2 turn will
expand the bundle diameter only slightly. That's analogous to
tightening with a fine-thread screw. If the the bundle is more twisted,
twisting another 1/2 turn will expand the bundle more rapidly, like
using a coarse-thread screw. Turning the wire nut won't compress the
bundle as tightly, and the nut will be less secure.

My BIL pretwisted his wire-nut connections as he'd been taught working
for an electrician. If he was connecting 4 conductors, he'd strip 2-3",
IIRC. The need for all that bare wire showed that the twisted bundle
had a much bigger cross section than 4 straight conductors, so it
wouldn't go as far into the wire nut. Twisting such a fat bundle meant
the conductors weren't nearly parallel to the axis of the wire nut; that
meant further twisting for a tight fit wasn't very effective.

That explains why the electrician's method required tape to secure the
nut. Tape was necessary for another reason. One had to estimate how
much insulation to strip before pretwisting a certain number of
conductors. This could result in bare copper extending beyond the skirt
of the wire nut. The method was apparently adequate for household
wiring, but I would not have wanted it in a vehicle, where connections
are not enclosed in boxes and are subject to vibration and tugging.
Even this article you posted the link to states, "Next, hold the wires
firmly together with the stripped ends parallel (step 1). Press the
connector over the wires. There should be no exposed conductor (step 2).
Twist the connector clockwise and stop when the splice is tight (step 3)."

Your own article states to start with the wires parallel, not a CCW twist.

Using solid conductors, I'd do it just like the example. I'd even add
those twists in the insulated conductors as a measure of protection
against tugging.

He says he doesn't pretwist because he wants to be able to undo his
connections easily. That sounds like saying the strength of a
connection comes from the clamping of the nut and not the twisting of
the conductors. I agree.

Good workmanship requires making sure a method works in a particular
case. The instructions for the wire nuts my BIL used said nothing about
tape, but the electrician who taught him had found that tape was
necessary to use a wire nut on a pretwisted bundle.

I found that the finely stranded conductors at the church twisted too
easily for the wire nuts to screw on properly. I didn't feel a gradual
increase in friction as I turned, and the conductors could be tugged
loose. I could get good mechanical connections if I twisted the
conductors CCW in order to give the wire nuts a 1/2-turn head start on
the CW twisting of the conductors.

The boys may not have known how a wire nut should feel as it screws on,
but they would have found the results of CW pretwisting unacceptable if
they had tugged each connection as I instructed. The boys and the
warden used the easiest method to put the wire nuts in place. It was
not what the manufacturer said or what I had found, and they must not
have tested their connections.
 
J

James Sweet

Jan 1, 1970
0
Where does the UL specify twisting conductors clockwise? Don't they
test connections after following manufacturers' instructions? The
instructions I've seen don't say the conductors must be twisted before
or during application of the connector.


I don't twist the conductors first. I strip off about 1/2" of
insulation, line up the tips of all the conductors, then screw the wire
nut on clockwise which then slightly twists the wires together as it is
tightened up. No tape is necessary, although I normally use a bit on #10
and heavier wire just to provide a bit more mechanical strength with the
stiff wire. I have yet to ever have a bad connection, although I've
repaired many poorly done and problematic splices done by others. My own
experience suggests that if you twist the wires up first, the wire nut
is not nearly as secure as it is if the metal insert screws onto
straight wires. The insert is harder than the copper and actually cuts
threads into the solid conductors, this is why the joint is so strong.
 
E

E Z Peaces

Jan 1, 1970
0
James said:
I don't twist the conductors first. I strip off about 1/2" of
insulation, line up the tips of all the conductors, then screw the wire
nut on clockwise which then slightly twists the wires together as it is
tightened up. No tape is necessary, although I normally use a bit on #10
and heavier wire just to provide a bit more mechanical strength with the
stiff wire. I have yet to ever have a bad connection, although I've
repaired many poorly done and problematic splices done by others. My own
experience suggests that if you twist the wires up first, the wire nut
is not nearly as secure as it is if the metal insert screws onto
straight wires. The insert is harder than the copper and actually cuts
threads into the solid conductors, this is why the joint is so strong.

I've had #10 wire make a rigid wire nut feel like it wouldn't fully
seat. I've also had the problem with #12 wire that had been hardened by
twisting and untwisting from another splice. A live-spring wire nut
worked better in those cases.

It was 25 years ago that I was splicing stiffened wire. It didn't occur
to me to secure wire nuts with electrical tape because I'd lost faith in
the stuff. I'd bought several rolls from an electronics place, but
after I taped a connection, the adhesive would eventually "melt" and the
tape come loose.

This left me wondering how I could predict that a roll of electrical
tape would be reliable. After some years, I bought a roll of good
stuff, but by then I was out of the habit of using electrical tape.

Tonight I looked at that good roll. The cardboard core is marked UL.
Why didn't I think of that 25 years ago!
 
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