Crimp-and-tape vs. wirenuts -- for hots?

I am redoing some wiring in our house that involves breaking and remaking some original connections -- ripping out and replacing boxes by larger (e.g., two-gang by three-gang). I find that in some cases all the conductors of the same color have been connected using crimps that have then been taped over -- even the hots. Is this kosher? Surely wirenuts provide better insulation than the tape. There could be 220/240 volts between conductors in some boxes because there are Edison circuits involved.

Should I use wirenuts for the reconnections? Crimps and tape take up less room.

And, while I think of it, is it OK to have circuits fed from different breakers in the same box (e.g., outlet and light switch)? One could assume that since the one circuit is dead (switched off at the panel), the other is too.

Perce

Reply to
Percival P. Cassidy
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Addressing the connection method: When I think of crimps, I think of the type that already have a plastic sleeve over a metal interior. However, I

*have* seen a type that's just a metal sleeve. As far as I know, they are intended only for joining bare ground wires.

Someone will stumble along here and claim otherwise, but I think electrical tape is for slobs and hacks who don't know how to make a secure connection, so they cover things up with tape to hide their incompetence. It also leaves things gummy. When I want to rewire something, my definition doesn't include wiping gunk off my fingers constantly because some monkey went nuts with tape.

I once asked a local inspector and was told it was perfectly legal to use crimps for house wiring, and was told that it WAS. There are two caveats:

1) You must use a crimp tool that actually shapes the crimp properly. You won't find such a tool at Home Depot or Lowe's. It'll take some effort. It requires a channel for the crimp to sit in, and a tooth-like prong on the opposite jaw. The tooth almost creates a hole in one side of the crimp. 2) If wires might need to be disassembled later, and they're already short, cutting off an old crimp will obviously make them even shorter. Use wire nuts in these situations. Have several sizes on hand.
Reply to
JoeSpareBedroom

[...]

Wire nuts are perfectly fine; crimps aren't unless they're made properly, and

- no offense intended - asking the question shows that you don't know how to make them properly.

It's "OK" in the sense that it is permitted by the NEC, although in my opinion it should not be -- for exactly the reason you cite. It would be a good idea to write a warning with a Sharpie on the inside of the cover plate.

Reply to
Doug Miller

I have a Gardner-Bender stripping/crimping/etc. tool that AFAIK is meant for this job, and I believe I know how to use it. Asking whether it's OK to do something has nothing to do, IMO, with knowing how to do it. There are many possibilities:

  1. I know it's OK and know how to do it.

  1. I know it's OK but don't know how to do it.

  2. I don't know whether it's OK and wouldn't know how even if it is OK.

  1. I don't know whether it's OK but know how to do it.

I believe I fall into the last category.

Actually I suppose there are yet other possibilities:

  1. I know it's not OK but know how to do it and will do it anyway.

  1. I haven't a clue but will do it wrong even if it would be OK if I did it right....

Good idea.

Perce

Reply to
Percival P. Cassidy

Sure its kosher when its done right. BTW, high voltage, high current cables - that is, thousands of volts and thousands of amps - use crimp (compression) connectors.

Surely wirenuts

Reply to
** Frank **

It wasn't so much the crimping I was questioning as the two or three layers of insulation tape vs. however many mm of insulation provided by a wirenut.

Perce

Reply to
Percival P. Cassidy

Of course more insulation is better, but r

Reply to
Terry

More insulation is better, but remember that the splice is usually tucked safely in the box

Reply to
Terry

Tape is OK. I would use more that 3 layers. Be careful of points and edges that can poke through the tape. It has to be listed electrical tape.

The crimps also have to be listed for purpose - including wire size and number of wires, stranded/solid, and voltage for insulated crimps.

-- bud--

Reply to
bud--

One more time: The tape is sloppy, and if the crimp is done right, there is absolutely no need for it.

This company makes the best crimps you can buy:

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On that page, you'll see a link to a pdf file which discusses proper crimping tools and techniques.

Although you can order directly from the company, there may also be an industrial supply dealer near you that sells their products.

Reply to
JoeSpareBedroom

on 7/20/2007 2:47 PM Percival P. Cassidy said the following:

I would avoid crimps for just one reason. What if you had to replace an outlet, light fixture, or switch that went bad, or wanted to upgrade to the latest and greatest fixtures or switches? Would you rather just unscrew a wirenut, or try to get the crimp off with a pair of pliers?

Reply to
willshak

With many people, (especially with those who live in countries where they are banned), there seems to be some sort of bias against the use of wire nuts, even though they are a perfectly acceptable and an NEC legally approved method of making splices. When done properly, by twisting the wires together with a pliers and applying the wire nut with a proper tightness, there is little chance the wire nut will come off or that the splice will become a high-resistance hot spot.

Wire nuts offer the advantages of simplicity, economy, speed, and the flexibility to make future changes without destroying the connecter.

Open up enough outlet boxes where the splices have been taped after 5,

10, or 20 years and you will, more likely than not, find examples where the tape has dried up or even fallen off the splices it was intended to cover.

Beachcomber

Reply to
Beachcomber

Two things:

If you can remove a crimp using pliers, it means the crimp wasn't installed correctly in the first place. If you need to change a connection, you cut on either side of the crimp. If you're running new wiring, you leave extra in case you need to cut out a crimp. If it seems that existing wiring is already too short to allow cutting later, use wire nuts.

Reply to
JoeSpareBedroom

These are the plain copper cylinders (more or less) that are crimped onto the wires. As supplied, they have no insulation, so obviously if they are used on hots or neutrals they need to be insulated afterwards. What would you use other than tape -- or shrinkwrap, I guess?

Perce

Reply to
Percival P. Cassidy

I must admit to having been horrified the first time I saw a wirenutted connection. Looked like some real Rube Goldberg affair. What I was used to seeing for electrical connections was a box made of insulating material, with firmly attached brass "busbars" with wires inserted into the holes and held secure by clamping screws.

I have read that the wires must *not* be twisted together first. In fact I just read a claim that UL approval of wirenuts depends on them making a secure connection without pretwisting the conductors.

The ones I just encountered were likely original (30 years) and the tape was tight.

Perce

Reply to
Percival P. Cassidy

Since the wrong kind of crimps were used, I would cut them out and change them to insulated crimps. If you have the wrong connectors, you don't use them and try and make them right. You stop the work until you have the right thing. A cob job might be appropriate when making toast, but not when wiring a house (or car, boat, or anything else).

Reply to
JoeSpareBedroom

Is your first sentence in your paragraph above a conclusion you reached from your second sentence, or was it a separate statement you read?

The seoncd sentence means that the wirenuts must be able to make a secure connection if the wires are not pretwisted. It does not in itself doesn't mean that the wires can't also be pretwisted. Or even that it wouldn't work better if they were pretwitsted.

I only do this stuff once in a while, and sometimes I don't pretwist, I guess usually when I don't have pliers handy, but I feel more confidant of the electrical connection when it is pretwisted. Based on my knowledge of things and materials and touching, I don't know how it could be otherwise.

Reply to
mm

On what is that conclusion based?

I would cut them out and change

Reply to
CJT

Bare copper cylinders need to be insulated after they're installed, right? One method would involve tape, which is sloppy and amateurish, and I don't care whose grandpappy did it and got away with it. The other method involves heat shrink tubing, which is miraculous stuff, but to use it

**correctly**, you should apply heat to all sides of the tubing. Not so easy with short wires in a box.
Reply to
JoeSpareBedroom

Your preference against it doesn't make it "wrong."

Reply to
CJT

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