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J Tiers
01-13-2013, 07:12 PM
For our friends elsewhere who don't use them..... Such as John S...... who just commented on them in another thread.

There are two different kinds....... one is good, and has a conical coil spring liner. They grip like crazy, and are as good as any other quality connection short of welding.

The un-mentionably bad ones are the old type, that has no spring..... just a roughly conical recess with some sort of thread in it..... you are supposed to screw it over the wires.... They are particularly evil, and I doubt they have been accepted in the US for 50 or 60 years..... They shouldn't have been ever accepted. As soon as there is any movement, the wires are loose....

Black_Moons
01-13-2013, 07:22 PM
Your doing it wrong then.

Iv used the copper cored threaded ones and they work fine, still sold here in canada, most are, The trick is to strip 1/2" or slightly more of wire, hold them side by side very precisely when you put the nut on. Then twist. And twist. And twist some more. If you start whining about losing your fingerprints, grab your plyers to finish them off or buy the nice blue ones with handles on them.

When done, you should be able to remove the nut and the wires are still twisted to eachother securely.

The wirenut is mainly just to twist the wires into a secure connection and then provide an insulator that won't fall off. Its not supposed to hold the wires togethor.

If you can yank on the wire and it comes undone before snaping off, you did it wrong.

darryl
01-13-2013, 07:22 PM
There are the type that you insert the wires, then tighten a screw, then screw the cover over that. I've seen lots of these get loose. Otherwise I like those wire nuts- you can twist them on to tighten a connection without having to take anything apart, and I've never seen one burnt up. To me, the integrity of the connection beats those where a screw has to be tightened down over the wires.

What do they use in Britain? Failure-prone crimp-ons? :)

J Tiers
01-13-2013, 07:36 PM
Your doing it wrong then.

Iv used the copper cored threaded ones and they work fine, still sold here in canada, most are,

Hmmmmm..... seems a while back someone from Canada was saying they were no longer accepted up there..... without, however, specifying the exact type.....

"Doing it wrong"??? I'm not doing it wrong, I never use that kind, and I don't think you can actually buy them anymore down here

The type I referred to with solid threads is old, were commonly made of ceramic, and had the threads inside.... I think others were made of various forms of plastic, which seems like it would be even worse. Nothing really holding the "cap" on, they were commonly taped.

If looked at as merely an insulating cap for the bare ends, maybe they actually are OK...... but even then, the twisting of wires together as the "sole connection" isn't good..... Some form of springiness to retain them is best.

Duffy
01-13-2013, 07:49 PM
I was told that originally the manufacturers provided, (sold?) a hand-held nut twister that was large enough that a person could twist the wires together fairly easily. Remember, these were introduced to replace double-taped twisted wire terminals, which, in turn, replaced twisted, soldered and taped. Does anyone remember the vulcanizing tape that was used over connections? The type that I recall was black with a white inner layer; once it was applied overnight, it had to be cut off bit by bit.
A couple of electrican friends told me that, for multiple terminations, (three or more wires,) they ALWAYS twisted the bare wires with pliers, trimmed them, and then applied the wire nut. They all felt that there was no certainty of a permanent cold connection relying on the torque applied through the wire nut.
I also understood that the old Marr connector, with the removable brass insert, was primarily intended for terminations of stranded wire, both high temperature 14 and 16 gauge and domestic 6 and 8. I remember seeing them in kitchen stove and dryer junction boxes, before these appliances were supplied with cords and rated outlets

sasquatch
01-13-2013, 08:03 PM
I remember seeing the old "Ceramic" ones mentioned.

The Mars now are great, and as stated i have never seen a problem with them. Millions of them have been used for quite a long time,, there could have been a problem years back if an unknowing homeowner twisted together copper and aluminum.

Black_Moons
01-13-2013, 08:04 PM
Some pictures for refrence:
Most common wire nut in canada:
http://www.electricmarine.com/web/images/images_1/wire_nut.jpg


Type with wings, verious sizes:
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Wire_nuts.jpg/220px-Wire_nuts.jpg
"In the UK, they were made out of ceramic and sold under the brand "Scruit." Their use was outlawed some fifty years ago."
Apparently ceramic was a bad idea. Or scruit didn't make them properly.

Here in canada, I have never seen an electrician use anything else for 14ga wire. If they where a problem for homes, We would have houses bursting into fire every other day by now.

With a good wirenut install, the wire past the insulation is usally twisted too, Its rather unavoidable to do:

http://z.about.com/d/electrical/1/0/y/3/-/-/wiresconnectedinjbox300.jpg

Further securing the connection by providing a little strain relief for moving the parts back into the junction box. You still have to strain relief the wire where it leaves the junction box, of course. (required by code)

macona
01-13-2013, 08:06 PM
I have seen wire nuts burn up and melt several times. I use these now:

http://www.smarthome.com/_/Wago/_/1xN/nav.aspx

They make life easier and reduce fatigue putting nuts on.

vpt
01-13-2013, 08:15 PM
Some pictures for refrence:
Most common wire nut in canada:
http://www.electricmarine.com/web/images/images_1/wire_nut.jpg


Type with wings, verious sizes:
http://upload.wikimedia.org/wikipedia/commons/thumb/f/f0/Wire_nuts.jpg/220px-Wire_nuts.jpg
"In the UK, they were made out of ceramic and sold under the brand "Scruit." Their use was outlawed some fifty years ago."
Apparently ceramic was a bad idea. Or scruit didn't make them properly.

Here in canada, I have never seen an electrician use anything else for 14ga wire. If they where a problem for homes, We would have houses bursting into fire every other day by now.

With a good wirenut install, the wire past the insulation is usally twisted too, Its rather unavoidable to do:

http://z.about.com/d/electrical/1/0/y/3/-/-/wiresconnectedinjbox300.jpg

Further securing the connection by providing a little strain relief for moving the parts back into the junction box. You still have to strain relief the wire where it leaves the junction box, of course. (required by code)



Also the common ones in america.

Weston Bye
01-13-2013, 08:20 PM
Back when I was self-employed building machine tool control systems, those dreadful wire nuts were never used. Instead, we used "Sta-Kon" uninsulated crimp-on ring terminals. Each wire would get a stakon and then 2 or more wires would be attached together with an 8-32 screw and nut. The whole thing would be wrapped up with electrician's tape. Early on, certain customers required motor terminations (subject to vibration) to be first wrapped with cambric tape before the electrician's tape.

I still do the stakons and screws and tape whenever I am called on to do repairs, but sometimes I return to something I repaired in the past only to find that someone else has used wire nuts.

Oh, well.

Boucher
01-13-2013, 08:27 PM
Some wire nuts have a steel inner cone with sharp corners like threads. There is an Anti-Oxidant compound that goes back to the time of Aluminum wire that should be used with these. It is important to have the correct number and size of wires and the correct stripped length. It is better to install the wires straight into the wire nut and not twist them together before insertion. In the tops of water well casing we sealed the wire nut with electrical tape and pointed the nose upward so that the wires formed a drip loop. ie any water that condensed on the wire ran away from the connection rather than into it.

Black_Moons
01-13-2013, 08:29 PM
I have seen wire nuts burn up and melt several times. I use these now:


I have seen wires burn up and melt several times. Does not mean you should not use wires, just means you should properly select and install them.

Too many people just don't use enough force when twisting wire nuts. When one friend asked me to see why his electrical work was not working, I gave the wires a light pull and the wire nuts poped right off, showing that the wires had never been twisted togethor and did not even have any marks from the thread.

Some people think they are just caps you lightly screw on. You seriously need to twist them till the wire outside the nut twists up and you can't twist anymore.

As for stresses, I would think getting pinched by a screw with absolutely no strain relief would apply more stress.
How tight are you supposed to tighten those screws anyway? And who has a torque screwdriver for me to borrow since 'Tight' has no real meaning whatsoever?

J Tiers
01-13-2013, 08:35 PM
I have seen wire nuts burn up and melt several times. I use these now:

http://www.smarthome.com/_/Wago/_/1xN/nav.aspx

They make life easier and reduce fatigue putting nuts on.

THOSE really ARE "dreadful"......

Fine for the moment, but after a while, they seem to loosen up, I'm not sure why. I've replaced a number of them that seemed to be heating up. In the ones I saw, which must have been applied 20 years ago, the "connection" is made by a "fishhook barb" that is both the spring, and the retainer. Apparently it doesn't always stay tight.

Any wire nuts that "burned up and melted" must have been poorly applied... in fact that is almost a guarantee, since the heating is evidence of a bad connection.

For the "goodness" of the screw and nut connection, see the thread about "found the problem with my lathe", where it looks like a screw and nut connection heated up and broke loose from the european connector block in a motor.

And speaking of european connectors..... those screw-block european connectors..... the ones made of THERMOPLASTIC......(sheesh) Best way in the world to turn a connection that heats up into a full-on across-the-line short..... I've seen a NUMBER of those melt and burn. And they can heat or come loose easily... the screw usually doesn't "catch" all the strands of the wire.... even if the wire is twisted before insertion.

Jon Heron
01-13-2013, 08:40 PM
I have seen wire nuts burn up and melt several times. I use these now:

http://www.smarthome.com/_/Wago/_/1xN/nav.aspx

They make life easier and reduce fatigue putting nuts on.
Those are junk and should be outlawed along with the "quick wire" push in connectors found on the back of residential receptacles and light switches. The problem is they have a very small contact area that relies on spring tension to maintain it. As soon as the terminal sees any heat the spring tension is gone and they start to heat up and fail.
As an electrician who drove a service truck for a few years I can tell you that the number one source of failed receptacles is from the quick wire sockets being used, the bad connection from them usually burns off the insulation far enough back on the wire that its a PITA to repair too.
Nobody working for me was allowed to use the junk quick wires and I would say that any electrician worth their salt would say the same.
Those wall nut style connectors have been around for years but have never taken off. A properly installed marrette will never fail.
Cheers,
Jon

portlandRon
01-13-2013, 09:09 PM
It's my understand the wire nut shown are not for connecting wire together they are designed to cover the bare wires ends. For proper connections the bare ends of the wire must be twisted together using a pair of pliers before the nut is used.

firbikrhd1
01-13-2013, 10:13 PM
According to the book "Practical Electrical Wiring" 19th edition, Copyright 2001, 2005 Park Publishing Inc. pg. 120:

Quote:
For wires 8 AWG (in some cases 6 AWG) and smaller, one of the most popular splicing devices is the twist on solderless connector, often called by the trade name "Wire Nut." [Two types] One type has a removable metal insert; the ends of the wires to be spliced are pushed into this insert, the setscrew of which is then tightened and the plastic cover screwed on over the insert. The other type has no removable insert but has an internal tapered thread; lay the wires to be spliced parallel to each other (if one is a bit smaller than the others, let it be a bit longer than the larger wires), then screw the connector over the bare ends of the wires.
Although many believe that the wires should always be twisted together prior to installing the twist-on wire connector, that is never required and may violate installation instructions for some of these devices. Leave the wires straight, just as you stripped them, and twist on the wire connector. End Quote

sophijo
01-13-2013, 10:35 PM
Any one seen/used "Gorilla" wire-nuts? They have a soft outer shell!

Willy
01-13-2013, 10:54 PM
According to the book "Practical Electrical Wiring" 19th edition, Copyright 2001, 2005 Park Publishing Inc. pg. 120:

And then we have this from Leviton on the "proper" way of installing wire nuts.

https://www.youtube.com/watch?v=32z6Q8--fEM

Be that as it may I do agree with the OP in his assessment there being both good and very bad examples of wire nuts.
But surely there can certainly be no other quick wire connection "system" with it's roots as close to hell as the cursed Scotchlok!

J Tiers
01-13-2013, 11:56 PM
The Leviton video has the wires twisted no more than necessary to do a basic job of holding them together. AND they clip the end to avoid the "horns".

Scotchlock? I'd forgotten about them...... IDC connectors are generally VERY reliable, but not the Scotchlocks of old.... I've seen them with the plastic turned to ash.... No idea what's wrong with them vs any others, but they were always unreliable when I have dealt with them.

Black_Moons
01-14-2013, 12:03 AM
And then we have this from Leviton on the "proper" way of installing wire nuts.

https://www.youtube.com/watch?v=32z6Q8--fEM


Thats the worst way to do wirenuts ever. Look at how poorly they twisted before he put the nut on, and how nothing twisted with the torque he used to put that nut on.

I bet just breath on it hard and it will fall off. And that short amount of electrical tape will turn to goo and fall off within a month.

dstig1
01-14-2013, 12:55 AM
I chuck one of these tools into a small Bosch hex-shank driver/drill and set the clutch to a decent number ~4-5 (a couple tries and you get it right). Page 3 in the PDF link. They seem to fit and work on every wire nut I have tried. Got it at the local electrical supply place as they had them sitting out. Had no idea they even existed before that...

http://multimedia.3m.com/mws/mediawebserver?mwsId=SSSSSu7zK1fslxtUnY_vMxmGev7qe 17zHvTSevTSeSSSSSS--

ikdor
01-14-2013, 05:39 AM
I'm rather fond of this type as it takes both stranded and solid wire:
http://www.nce.com.hk/images/wago-309-lgt-222.jpg

Igor

Black Forest
01-14-2013, 06:30 AM
I'm rather fond of this type as it takes both stranded and solid wire:
http://www.nce.com.hk/images/wago-309-lgt-222.jpg

Igor

Do you have a name for that type of connector? I have never seen a connector for braided or stranded wire. I would like to see if they are available in Germany.

garagemark
01-14-2013, 06:46 AM
A PROPERLY installed wire nut will never burn. An improperly installed wire nut will eventually get hot and fail. The same can be said for just about everything mechanically that is built (assuming not under engineered).

As a thirty some year electrician by trade, I too have seen smoked wire connections of all types; wire nuts, Wagos, terminals and tape, solder joints, etc... They all had one thing in common; they were improperly installed. But one other thing to remember here, you are looking at a few failures as compared to literally millions of connections. So, wire nuts are a pretty good electrical connection for branch circuits. Wagos are new (relatively).

3M, one of the worlds largest manufacturer of wire connecting devices, suggests NOT twisting wires together before screwing on the wire nut. But I suppose it's your choice. Chances are still very good that it will work either way.

Ian B
01-14-2013, 07:40 AM
BM,

They're made by Wago: http://www.ebay.co.uk/itm/120871981017?var=420067594977&ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1438.l2648

Ian

ikdor
01-14-2013, 07:53 AM
BF,
They're actually made in Germany :-)
Search for Wago block

Igor

J Tiers
01-14-2013, 08:18 AM
Thats the worst way to do wirenuts ever. Look at how poorly they twisted before he put the nut on, and how nothing twisted with the torque he used to put that nut on.

I bet just breath on it hard and it will fall off. And that short amount of electrical tape will turn to goo and fall off within a month.

??????????

There is no actual requirement to twist for there to be effective contact, and heavy twisting can make the total diameter of the wire bundle (as twisted) larger, which could require a larger nut than what is approved for the connection of those wires.

In the video, the wires are twisted only enough to hold together, which makes sense.... the twist is not so much for the connection as it is for the wires to be stable. The one problem with merely sticking in the wires straight is that they may be able to spin around and be loosened while folding them back into the box. but they still make a good connection.

Any twisting of the wires OUTSIDE of the wirenut has no effect at all. obviously no contact is made out there. The only possible reasons for it are to offer some inspectable proof that the wirenut was fully installed....... it stopped turning and the wires were twisted.... and one might possibly argue that the connection is to some extent even further stabilized by the external twisting. Other than that, there isn't any reason for it at all if the nut is fully installed.

vpt
01-14-2013, 08:34 AM
Some wire nuts have a steel inner cone with sharp corners like threads. There is an Anti-Oxidant compound that goes back to the time of Aluminum wire that should be used with these. It is important to have the correct number and size of wires and the correct stripped length. It is better to install the wires straight into the wire nut and not twist them together before insertion. In the tops of water well casing we sealed the wire nut with electrical tape and pointed the nose upward so that the wires formed a drip loop. ie any water that condensed on the wire ran away from the connection rather than into it.


Anything around the water we use heat shrink and set screw connectors. Wire nuts only get used in dry boxes in buildings.

http://ak.buy.com/PI/0/350/204597542.jpg

outlawspeeder
01-14-2013, 09:15 AM
Wire nut should not to be use in vibration area. That is where most people have problems. When hooking up Eq, if the junction box is mounted on the EQ it should have screw down connections, although most motors have the junction box on the motor with wire nuts. If the box is on the wall the wires should be clamped going into the junction box, stopping the vibration and then allow for wire nut use.
The other problem I find is wire nuts come in many sizes and when someone put three 10ga wires into a yellow wire nut, one or two thread is holding it on. Each company has what is allowed for their nuts. It is printed on the box.
For Ideal: http://www.idealindustries.com/media/pdfs/products/ideal_ul_listed_combinations.pdf
As far as putting a nut on grab the wires you want. Line up the ends or cut to the ends all at once. Put the wire nut on when the wires twist one full revolution twist of the wire outside the nut from the nut twisting force and you’re done. This will lock the wire together, and insure the nut is tight.
Wire nuts are allowed for use on autos. This is something I do not condoned due to vibration and water.

If you not sure a wire nut will hold use a clamp, or terminal strip.

Mcgyver
01-14-2013, 09:15 AM
I can't recall ever having trouble with a 'Marr' or marrette connector (what call wire nuts) for regular house hold stuff. twist with lineman's pliers in the right direction and install.

what I don't like though is connecting stranded, either to other stranded or worse to solid. I've been using those connectors that look like a marr from the outside but have a removable brass piece with a screw to lock the wires. They never seem that solid because the screw and thread are sketchy - very short length of engagement. What do you pros think is the correct way to fasten stranded wire?

sasquatch
01-14-2013, 09:41 AM
I'm certainly no "PRO" but stranded, and stranded to solid i always solder them.

Boucher
01-14-2013, 09:49 AM
For connecting two wires the stakon sleeve is much more reliable than the screw type shown. For connections below the water level (think pump motor splice) a double jacketed heat shrink is used. The inner material softens or melts and the shrinking outer tube fills the splice zone. In water wells in areas with deep frost lines a pitless unit conducts the water through the casing wall below frost level. The pressure switch is inside the casing attached to the pitless unit with a bayonett connector. The power supply wires must be attached in the upper section of the well casing which in some cases sweats and therefore is a very wet environment. The best way to attach these wires is with good quality wire nuts filled with a dose of Anti-Oxidant grease. The wire nut is taped up with either the rubber or plastic tape. The nose of the wire nut is pointed upward to form a drip loop to shed any condensed water away from the wire connection.
Failure to use the Anti-Oxidant often results in corrosion of the wire nut spring and the inability to remove said connector other than cutting it out. I still carry a tube of grease in every tool box and use it on all sorts of connections especially battery terminals.

sophijo
01-14-2013, 09:54 AM
How about those wire nuts pre-loaded with silicone caulk.....any good?

alchymist
01-14-2013, 09:59 AM
When doing solid to stranded, I strip the stranded a half inch or so longer than the copper, and wrap several twists of stranded around the copper in a spiral motion before installing the wire nut. Makes a tight secure connection.

Boucher
01-14-2013, 10:05 AM
We also soldered any thing larger than #8. It is important to clean solder flux. The silicone filled nuts are used on sprinkler controls that use solid wire, also on telephone connections with solid wire.

Paul Alciatore
01-14-2013, 02:45 PM
Some good points here, BUT

what I do is:

1. strip the wires a bit long
2. align the cut edges of the insulation
3. twist the stripped parts enough to hold them together (lineman's pliers)
4. trim the twisted bundle to correct length (again, lineman's pliers)
5. apply and tighten wire nut until I can NOT turn it any more BY HAND (no tools used here)

Never had a bad connection that way.

I would only use tape if there was a separate reason for that (like keeping moisture out). There is usually no need for tape inside an electric box or other enclosure. I am careful of how I position the splices before I close the box.

YES, the twisted wire outside of the wire nut ONLY serves to indicate that sufficient force was used in applying the wire nut. But, if you do it properly, this twist is unavoidable unless special tools are used. It is a by-product, not a feature of the process.

I like the types with springs and wings. I avoid the ones without springs or some kind of metal inserts inside them.

As for wire nuts vs crimps or screw connections, I have seen far more problems with the crimps and screw connections. Not that they are bad, but there are more things that can go wrong if they are not properly done. Wire nuts ARE very reliable.

Paul A.




??????????

There is no actual requirement to twist for there to be effective contact, and heavy twisting can make the total diameter of the wire bundle (as twisted) larger, which could require a larger nut than what is approved for the connection of those wires.

In the video, the wires are twisted only enough to hold together, which makes sense.... the twist is not so much for the connection as it is for the wires to be stable. The one problem with merely sticking in the wires straight is that they may be able to spin around and be loosened while folding them back into the box. but they still make a good connection.

Any twisting of the wires OUTSIDE of the wirenut has no effect at all. obviously no contact is made out there. The only possible reasons for it are to offer some inspectable proof that the wirenut was fully installed....... it stopped turning and the wires were twisted.... and one might possibly argue that the connection is to some extent even further stabilized by the external twisting. Other than that, there isn't any reason for it at all if the nut is fully installed.

quasi
01-14-2013, 02:57 PM
paul alticore is correct, you twist the stripped wires together first, trim to length and twist the wirenut, marrette, scotch lock,... on by hand. The only way one of these can melt is from a loose conection inside of it.

wierdscience
01-14-2013, 03:14 PM
If a wire nut has a threaded metal insert it generally will work fine,the all palstic ones are junk IMHO since they easily slip and loosen off.

Wiring motors in industry sometimes they allow wire nuts,but require them to be wrapped in rubber tape for vibration.The rest of the time it's ring terminals and screws and then tape.

Black_Moons
01-14-2013, 04:39 PM
??????????

There is no actual requirement to twist for there to be effective contact, and heavy twisting can make the total diameter of the wire bundle (as twisted) larger, which could require a larger nut than what is approved for the connection of those wires.

In the video, the wires are twisted only enough to hold together, which makes sense.... the twist is not so much for the connection as it is for the wires to be stable. The one problem with merely sticking in the wires straight is that they may be able to spin around and be loosened while folding them back into the box. but they still make a good connection.

Any twisting of the wires OUTSIDE of the wirenut has no effect at all. obviously no contact is made out there. The only possible reasons for it are to offer some inspectable proof that the wirenut was fully installed....... it stopped turning and the wires were twisted.... and one might possibly argue that the connection is to some extent even further stabilized by the external twisting. Other than that, there isn't any reason for it at all if the nut is fully installed.

Uh, Yes of course theres a requirement to twist the wires *WITH* the nut.

The twisting *inside* the nut expands the wires tight inside the nut. If you stick the wires straight in and don't twist the nut hard enough to twist the wires... Well, thats 100% improper install and WILL come apart and WILL cause fires. Guarenteed.

The wires are not twisted enough to hold togethor in the video, a little movement will unscrew the wires with that little amount of twist.
The twist IS 100% for the connection both electricaly and mechanicly. The wire nut is only to improve and insulate the twisted connection. Once a wirenut is used the wires should be so twisted as to be able to remove the wirenut and not be able to seperate the wires without untwisting it with plyers.

Twisting of wires OUTSIDE the wirenut provides strain relief (With solid cored cable) and helps reduce the stress on the actual connection.

Its also a VERY good inducator that it was done right, assuming they didn't pretwist the ends of the wire before puting the wire nut on.

Black_Moons
01-14-2013, 04:45 PM
If a wire nut has a threaded metal insert it generally will work fine,the all palstic ones are junk IMHO since they easily slip and loosen off.

Wiring motors in industry sometimes they allow wire nuts,but require them to be wrapped in rubber tape for vibration.The rest of the time it's ring terminals and screws and then tape.

Never seen an 'all plastic' wirenut. Don't think I would use one if I did...

And as for soldering stranded wire, Be careful, if the solder soaks into the wire under the insulation you now have a *very* brittle connection. Stranded wire with a soldered section should be *very* well strain relieved.

I have seen lots of stranded cable snap at the point where soldered. And while I hate using screws terminals and wirenuts on stranded wire, they do seem to survive vibration better then when soldered.

krutch
01-14-2013, 05:46 PM
I don't like 'em cause they can loosen with time and heat. One should tape them after twisting the connection to prevent loosening. Latest wiring I did I used splice cap connectors. They come in two pieces, a short metal tube to house the wires after which get crimped and a plastic cap to cover the 'splice'. So far I have had no issues with this style connection. The twist type will loosen with any heating of the connection or mouse traffic on them. I have a light in the house which is twist connected and it losses connection after being lit for a length of time. To fix it I have to tear out a patch of celing. Not something I want to do, so the light stays off.

vpt
01-14-2013, 06:56 PM
Anyone ever use that "spray tape"? Advertised as electrical tape in a rattle can.

Joe Rogers
01-14-2013, 07:07 PM
I don't like 'em cause they can loosen with time and heat. One should tape them after twisting the connection to prevent loosening. Latest wiring I did I used splice cap connectors. They come in two pieces, a short metal tube to house the wires after which get crimped and a plastic cap to cover the 'splice'. So far I have had no issues with this style connection. The twist type will loosen with any heating of the connection or mouse traffic on them. I have a light in the house which is twist connected and it losses connection after being lit for a length of time. To fix it I have to tear out a patch of celing. Not something I want to do, so the light stays off.
I thought code required any splices to be in a box accessible through a cover?
Joe

darryl
01-14-2013, 08:45 PM
Stranded to solid, I like to solder, then place a wire nut mainly as insulation. Solid to solid, I like the wire nut better than any other connector I've seen. As many have suggested, they need to be twisted on tight enough. I don't know about some of those newer ones, but wherever they rely on a springy contact they're off my list. Some of those newer ones look like they rely on the plastic to not creep and lessen the force over time. I'd be leery-

It occurs to me that an electrical inspector might look at these various things and not pass them. And what about the insurance company- some deviation from the norm in your area, and your insurance is invalid- ?

J Tiers
01-14-2013, 08:59 PM
I thought code required any splices to be in a box accessible through a cover?
Joe

It sure does......

All boxes must be accessible, and all connections must be in a box.

perhaps we have "uncovered" part of the problem with that installation? If we know ONE thing is done wrong..........then........... ;)

J Tiers
01-14-2013, 09:12 PM
Uh, Yes of course theres a requirement to twist the wires *WITH* the nut.

The twisting *inside* the nut expands the wires tight inside the nut. If you stick the wires straight in and don't twist the nut hard enough to twist the wires... Well, thats 100% improper install and WILL come apart and WILL cause fires. Guarenteed.

The wires are not twisted enough to hold togethor in the video, a little movement will unscrew the wires with that little amount of twist.
The twist IS 100% for the connection both electricaly and mechanicly. The wire nut is only to improve and insulate the twisted connection. Once a wirenut is used the wires should be so twisted as to be able to remove the wirenut and not be able to seperate the wires without untwisting it with plyers.

Twisting of wires OUTSIDE the wirenut provides strain relief (With solid cored cable) and helps reduce the stress on the actual connection.

Its also a VERY good inducator that it was done right, assuming they didn't pretwist the ends of the wire before puting the wire nut on.

Well, that is indeed your opinion.......

It doesn't jibe with industry opinion among the folks that MAKE the wire nuts...... some say no need to twist, others suggest a "stabilizing" twist..... We have already seen that such is the case.... two manufacturers with one in each camp.....

Now, as for the "guarantee" of a fire...... Strong words, and, unfortunately, clearly not the case, however attractive the idea of an "absolute requirement" is.

With the old all-plastic caps, it surely WAS the case..... the cap was merely an insulator applied over a twisted connection.

As they used to say at my old work, "not no more"...... Modern wire nuts don't rely on the twist as the sole connection, nor the sole means for physically holding the wires.

In the first place, the wires will be twisted even if they start straight, particularly stranded wire. In the second place, manufacturers do not require a tight twist. in the third place, it is obvious that a springy retainer will hold the wires together tightly....whether straight or twisted

Which is not to say that there is a problem with a twist in every case..... it can no doubt be helpful. But binding the wires up in a tight fat twist is simply not required. So far we have not ONE manufacturer who even suggests it....... can you find one?
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This sounds like a case where the term "wire nut" means vastly different things to different people, who react to the term per their own interpretation. Which may not be what the others have in mind at all.

wierdscience
01-14-2013, 09:22 PM
Anyone ever use that "spray tape"? Advertised as electrical tape in a rattle can.

Yes,I have used both the spray and the brush on.The item needs to be clean and free of oil and dirt.I hit stuff with brake clean or acetone first for a good bond.

Works good for applications where moisture is a problem,cars,boats etc.

The black brush on is also great for patching cuts and holes in welding lead insulation before they get worse.Takes a couple or three coats but holds up well.

firbikrhd1
01-14-2013, 09:28 PM
Some here have mentioned wire nuts as being the cause of a fire. I'm not going to say it's never happened or can't happen but I will say that in nearly 30 years as a firefighter I never saw a fire started by wire nuts. Considering there are millions if not billions of them in use the odds are pretty high that a fire will be caused by some other issue. Most fires caused by electrical problems that I saw were caused by extension cords used as permanent wiring or too small for the load applied or damaged wiring where the wire was crushed by furniture, run under carpets/rugs or the insulation was damaged.

wierdscience
01-14-2013, 09:45 PM
Never seen an 'all plastic' wirenut. Don't think I would use one if I did...

And as for soldering stranded wire, Be careful, if the solder soaks into the wire under the insulation you now have a *very* brittle connection. Stranded wire with a soldered section should be *very* well strain relieved.

I have seen lots of stranded cable snap at the point where soldered. And while I hate using screws terminals and wirenuts on stranded wire, they do seem to survive vibration better then when soldered.

Agreed,I should have mentioned I don't solder.I use quality stake on terminals and wire stakes.Good ones will cold weld the terminal to the wire as it crimps.

garagemark
01-15-2013, 08:08 AM
Cut a wire nut apart. It is not simply a tapered thread, it is a spring thread. If installed correctly it will take an immense number of heating/cooling cycles. But again, if properly installed, there will be no heating at the connection. At a 3M company demonstration, they installed a wirenut to two wires and then mechanically pulled both ways until it parted. The wire broke far from the connection.

Some folks just don't get it. The UL listing (in the US) is verified using the manufacturers installation instructions. If you don't install them like the manufacturer specifies, then you screwed up. The debate on how to install a wirenut is moot, unless you have copy and pasted the instructions from the manufacturer. Here is one:

http://i114.photobucket.com/albums/n277/mdshunk/73binstructions.jpg

In all fairness, it states that pre-twisting is unnecessary. Some will take away that this means twisting is permitted. If you are one of those people, then keep twisting. It's just another operation to have to do.

And this is an Ideal application chart. It specifically states for use on either stranded wire, solid, or combination of both:

http://www.idealindustries.com/media/pdfs/products/references/ideal_ul_listed_combinations.pdf

This is but one example. 3M (Scotchlock brand) instructions are similar in nature. IMO wirenuts are by in large safe. There are billions in use, and are in almost every residence in this country. Nuff said.

JRouche
01-15-2013, 12:11 PM
When I have to use wire nuts I really like these Ideal brand nuts. Nice large wings to grip and the inner threads grip the wire very well. Oh? Made in USA so.... JR

http://img.photobucket.com/albums/v366/Jrouche/HSM/connector.jpg

krutch
01-15-2013, 01:24 PM
I thought code required any splices to be in a box accessible through a cover?
Joe

The connection is accessible at a box. However I can no longer squeeze through the opening to get to the box. When that was installed, one could get to the box and the house was still under construction. The access for that fixture is in the attic and there is enough space for a child to get in there. I don't plan to send a kid in to fix that!

Paul Alciatore
01-15-2013, 04:39 PM
Another good reason for taping a wire nut splice.

On the twisting thing, I know it is optional and I have tried it both ways. I just find it easier to complete the connection if I twist them a bit first, especially if you have more than three wires in there.

Paul A.




If a wire nut has a threaded metal insert it generally will work fine,the all palstic ones are junk IMHO since they easily slip and loosen off.

Wiring motors in industry sometimes they allow wire nuts,but require them to be wrapped in rubber tape for vibration.The rest of the time it's ring terminals and screws and then tape.