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new fangled "wire nuts"

migraine's picture

I gave up and hired someone to wire our new house after hearing from some locals on how they have had to deal with the local Washington state eletrical inspector.  Glad, I did.  There ahave been alot of changes since I last wired a house.  Plus, his price was very reasonable and with no "hidden charges".

What I did see him use was a crimp style wire nut, like they have for #18-24 wire, as in phones, etc.  But these were for #12 and #14 wire.  He says they are even better than wire nuts and you know when they are crimped right.  Which means, no more potential light flickers.  And, boy do they leave alot more room in the box.  I just now need to find some that are large enough for #10 and #12 THHN stranded wire since this is what I will be using to wire my shop with 

Any body have additional input on these suckers??


(post #95137, reply #1 of 15)

Are the smaller ones blue, and the larger ones yellow?  I have used those, with mixed results.  If you read the instructions (me neither) it says that the crimp has to be on the side opposite the seam in the metal sleeve...but how do you see the crimp when the wire is inserted?  It takes a bit of a grip to crimp the tubes, at least for me...maybe there are better crimpers.  Biggest problem:  if you have to take the joint apart, the connectors are not reusable, and you lose a bit of wire.


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95137, reply #2 of 15)

What your describing is the newer IDC, Insulation Displacement Contact, type connector. They are UL listed and not considered a major safety hazard.

IDC devices or connectors have a thin sheet metal fork, contact plate, inside them that makes and maintains the electrical connection. The idea is that an insulated conductor is placed at the thin opening between the tines and then forced down into the gap. The motion against the thin metal edge forces the insulation from between the metal of the plate and the copper of the wire.

The gap is designed to be slightly smaller than diameter of the conductor so that the plate has to flex slightly so it maintains a firm contact against the conductor. In theory this makes an effective connection without having to strip or twist wires. That is not to say that I like or trust them.

Mobile homes have long used what are commonly called, along with a long string of epithets, modular devices. These also use the IDC technology. Cable would have its jacket removed and the insulated conductors aligned with the IDC connector plate. Then the back would be pressed into place forcing the conductors down into place where then, usually, make a sound connection.

The problem I have seen with the IDC connectors is that the actual cross-section of the contact is IMHO often rather small. This is not a major issue with telephone systems where the IDC connectors were effectively used. The issue with the smaller contact area I have, from experience with modular devices primarily, is that this constriction often heats up when asked to carry heavier current loads.

This heat build up appears to weaken the hold of the IDC contact plate. I think due to loss of tempering. This then allows the connection over time and with heat cycling to loosen eventually enough to arc. Due to the construction of these devices and the inherent safety of having connections in a box this arcing is much more likely to clear, disabling the circuit but avoiding any greater problems, than overheat to the point of causing a fire.

In my opinion IDC connectors should remain where they have a proven record, telecommunications. I would not not use these connectors on my own home nor will I, without dire threats and strong coercion, use these connectors on the job. Wirenuts are IMHO the far superior method. A good quality wirenut creates a much larger contact are between conductors and the interior constricting spring. 

Additionally the spring, in most models of connector a floating design, is free to expand and contract with the conductors as it heats and cools so that the connection does not loosen even after many heat cycles and long use. Wirenuts have a long history and if properly used with due care they are extremely reliable and safe.

Ideal, a major electrical manufacturing company, has come out with a similar connector to the IDC type that uses a different system. Their offering is basically a plastic body with angled spring plates that make contact with a prestripped conductor. This is very similar to the mechanism used on some receptacles and derisively known as 'quick wiring' or 'push in' connections. These, like the IDC system, are less a safety than a reliability issue. IMHO good and conscientious electricians do not use 'push in' connections and so should not use these, or the IDC, connectors.

Not as long as wirenuts, particularly the really good ones, are so inexpensive, available, easy to use, effective and safe.


(post #95137, reply #3 of 15)

Those things have been around a long time, called Scotch Locks I think.

Auto uses, stero installers, hacks in general use them to tap into wiring where they shouldn't be messing.

As 4lorn1 sez, the contact area is tiny if this is the same thing you're describing.

I have some old crimp gizzys, little sleeves that go over the twists and a crimper with a hole in the center that squeezes 4 spots around it at one time.

Works great, can't remember the name of it though.

Joe H

Edited 4/30/2004 8:32 pm ET by JoeH

(post #95137, reply #4 of 15)

I recently used a couple of Plugmold brand plugstrips...about 4 ft long w/ 6 rceptacles...they came with square push-on wire splices.   The grip seemed to be pretty tight, as it was a struggle to pull the wire back out.


Whenever you are asked if you can do a job, tell'em "Certainly, I can!"  Then get busy and find out how to do it.  T. Roosevelt

I'm sorry, I thought you wanted it done the right way.

(post #95137, reply #12 of 15)

Bucahnan? did you snap a nylon boot over them? those things werre great on exterior wiring ,,,,,,pole bases and wall-paks for example. I still have mine and the damn thing still works.

BTW I still have my Briegel tool as well


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(post #95137, reply #5 of 15)

Now that's what I call an 'informative' post.  Very interesting, glad I tuned in.

(post #95137, reply #6 of 15)

I like bucannon.

Insert initially amusing but ultimately annoying catch phrase here.

(post #95137, reply #7 of 15)


While not a proffesional electrician I do a fair amount of electrical work and have had some experience in commercial electrical in the past.  Every once in while someone asks an electrical question and I think "hey I know some about that".  I open it up and read your thorough, complete well written reply and think man nothing more to say about that! 

You should write a book.  Your messages are so insightfull and well written that it really is good reading and informative.  DanT

(post #95137, reply #8 of 15)

I think what migraine is describing is the crimp-style connectors similar to what you see inside appliances. The connector slides onto the stripped wires similar to a wire nut but then is crimped with a crimping tool to compress the metal cylinder inside the connector onto the wires.

These can produce a connection much more secure than a wire nut, and the connectors occupy considerably less volume.

The IDC Scotch-Loc connectors don't require a specialized crimping tool but occupy (in my experience) more volume than a standard wire nut.

Of all the preposterous assumptions of humanity over humanity, nothing exceeds most of the criticisms made on the habits of the poor by the well-housed, well-warmed, and well-fed.  --Herman Melville

(post #95137, reply #9 of 15)

the ones you describe sound like the type a local electrician used for a few odds and ends connections when i had a new 200a panel put in my shop awhile back.  they're little clear cubes with an orange base that has four holes for inserting 12g & 14g.  while they seemed very secure from a 'pull-out' standpoint, the contact area looked very small- much like the 'stab in' connections on the back of a light switch.

i haven't seen them in any stores around here and not too sure i want to use them anyway.  (btw- the inspector apparently thought they were ok)


(post #95137, reply #10 of 15)


on a side jack here..worked with an electrician years ago..he had a way cool screwdriver that had a hollow handle..for tightening nuts..too cool for sore fingers

was wondering ..does Klien make one? can't seem to find one..or maybe a UNIBIT and a "standard" swivel driver?..

any ideas?



Spheramid Enterprises Architectural Woodworks

Repairs, Remodeling, Restorations.   

(post #95137, reply #11 of 15)

Are you talking about nut nuts or wire nuts?

Try Ideal and 3M for wire nut drivers.

. William the Geezer, the sequel to Billy the Kid - Shoe

(post #95137, reply #14 of 15)

Walnuts of course <G>

Wire nuts...looks like Ideal is the ticket...

didn't wanna screw up a good swivel driver with a unibit..besides the Klien has the + or - on the handle end so's ya know if its a phillips or not with a pouch has WAY too many handles stickin out..



Spheramid Enterprises Architectural Woodworks

Repairs, Remodeling, Restorations.   

(post #95137, reply #13 of 15)

you might try IDEAL I think they make that screwdriver

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(post #95137, reply #15 of 15)

I have seen a few screwdrivers with built in wirenut wrenches, I use this term for lack of a better one. I have also seen or used a few dedicated plastic wirenut wrenches. These units are sometimes provided with large wirenut orders as a bonus. There are also a few wirenut companies that produce these wrenches with a shaft designed to be chucked into a drill. The manual ones I like better as the power ones don't give me a feel for the tightness of the nut.

I like the general idea of a wrench when there are hundreds of the connector to install. Doing them by hand can cause cramps and blisters on fingertips. This can get to be quite painful. Anything that reduces wear and tear or repetitive stress is beneficial.

In use these wrenches work fairly well when the design of the wrench matches the wirenuts used. Often a wrench designed for one brand doesn't work effectively on another. I haven't seen any that work on all, or even most, brands.

I have played with short lengths of various sizes of reinforced rubber fuel line. Sometimes it worked. Idea being that the rubber has enough friction against the plastic of the nut and the added diameter increased leverage so that there was less need to tightly grip the nut. This was hit or miss.

I have had more consistent results wearing gloves. Thinner pigskin, similar to driving gloves, work OK. Cotton ones with crinkly latex gripped well and also were OK. Problem is that electrical work is fiddly and the gloves get in the way. At the end of a long day twisting wirenuts I have been known to use my pliers on the beasts