I thought stranded couldn't be used under screws but I looked a while
and didn't find a restriction. It is definitely can be a problem. I
break the wire into 2 sets of strands and twist them tightly - works
good except behind device grounding screws. Can always pigtail to solid.
Poke in connections tightened by screw work good. I also thought
stranded couldn't be used with back-stab connections but in 1991 it could.
What is it on this user group about wire nuts. I work in a plant and it is
hard telling how many thousand connections are made with wire nuts. I would
guess it has to be around 100,000 or more. Everything from some low level
signal wires up to some 10 HP 480 volt 3 phase motors. Most all the wire is
stranded. If they are put on correctly we have almost no problems with
them. I don't usually use any tape on them except for some motors that seem
to shake and viberate alot. The tape is not so much for the wire nuts
themselves, but a few have rubbed through the insulation of the wire nuts so
much of the tape is just around the thin covering on some of the wire nuts.
The ones we use do not require any twisting. Just cut the insulation to the
proper length for the wirenut and put the ends together. Then let the
turning of the wire nut take care of things.
I use them when appropriate, but I've seen them fail (as you probably have).
There are boxes which you cannot change unless you want to rip it out and
replace with a bigger one. If the box is too small and the existing wire is
crowded, wire nuts make me nervous. I'll use crimps, as long as there's
enough wire to work with in case the crimp has to be cut off at a later
date. For new work, I always install an oversized box so there's enough room
to use wire nuts correctly.
If you look at commercial installations youy will seldom see anything
but stranded THHN. It works just fine on screw terminals and wirenuts.
They are both listed for stranded wire. Maybe homeowner/electricians
are just not up to the task ;-)
Seroiusly, if you twist the wire tightly it will be fine. Some old
timers say twist it backward from the way it is made. That does seem
Yea, I havn't had problems with tightly twisted stranded on hot and
neutral. I'm not real happy with the ground because the screws don't
have adjacent barriers to prevent the wire from spreading/coming out
like the hot and neutral do. Backwards is an interesting idea.
You have to be more careful using wirenuts on stranded but made right
they are reliable.
On 26 Jan 2006 12:41:46 -0800, email@example.com wrote:
It's not a bitch to work with the soild #12 wire either after doing it
for years and years....
Always pre-start the bends before cramming the wores in the box. Just
cramming makes the job tough and is more likely to develop a short or
Want a challenge, try using #10 wire in a standard box with an outlet
or switch. When I used to work for electricians, I once ran into a
house that someone had used a whole bunch of #10 for 15 and 20A
circuits. It was definately a low loss, and would never overheat, but
working with it was a nightmare.
All romex (nm) and armored cable is solid. I have NEVER seen any
stranded permanent electric wire used in a house.
I did also notice that it appears older wire was thicker than todays
As for 12 guage being a pain in the ass to work with??? Bah! you'll
get used to it, just like anything else. I rather have the higher
compacity cable in the walls just in case I want to go 20 amp
rather then having to rewire when all the walls are up.
On 26 Jan 2006 13:01:51 -0800, firstname.lastname@example.org wrote:
There's plenty of THHN 12 ga. stranded in my house. Some people
complain that HD doesn't sell THHN solid anymore, This may have
recently changed, but in NY City all the wiring in your house had to
be armored cable (in walls) or in conduit (exposed). The stuff that's
in conduit in my house is largely stranded. It's easier to pull
through the conduit. It seems to be powering this computer very
If I had to guess as to why older wire is thicker than new wire with
the same gauge rating it might be more of a quality control issue than
anything else. I bet the manufacturing process today is more accurate.
I believe that there was some copper clad aluminum wire used for house
wiring a while ago.
Aluminum has only about 70 percent of the conductivity of copper. If
what you found is copper clad aluminum then it makes sense that it's a
bit larger in diameter, but marked 14 gauge because it has the same
current carrying capacity as 14 gauge solid copper wire. Try filing on
the wire and see if you get down to aluminum.
If that's not it, then I'm gonna make a WAG that if your vernier shows
the older copper is in fact solid copper and of a larger diameter, the
difference may be because the newer insulation materials can withstand a
bit more heat than the older stuff could. So, they can dissipate a few
more watts in resistive losses without danger of the insulation going up
in smoke or falling off. But that's a verrrrry WAG I theenk.
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