I hate to waste peoples time with what seems like a dumb question, but this one has been driving me nuts.

Are UL listed "yellow" insulated crimp connectors (Barrel connectors) an approved splicing method? The application is #10 THHN stranded in a 18x18x6 steel box. They were used to splice a couple of 30A feeders to some fans. The crimps are perfect, the wires are tight.

It's weird...wish I had a camera.

I would think that you have answered your own question. If they are UL listed and they are used within the limitations of that listing I cannot see how anyone could turn you down on them.

Of course I have had a fire pump controller that was UL listed as Suitable for use as Service Equipment red tagged because the inspector wanted a fused disconnect ahead of it. The contractor I was working for obliged him because his order made it an extra for us. If he had just written it up for the lack of a Grounding Electrode system and their failure to pull a grounded conductor from the wye connected transformer to the controller I'd have been silently cheering him on but I digress.

My point is that just because we haven't seen it done that way before does not mean it is bad practice let alone a code violation. Remember that the code itself says
[90.1 Purpose.
(C) Intention. This Code is not intended as a design specification or an instruction manual for untrained persons.] Copyright 2002 National Fire Protection Association.
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Tom H

Tom- Just a thought from a wondering mind, Does that mean that it is a design manual for trained persons?

"...Does that mean that it is a design manual for trained persons?"

Probably meant as a joke, but a lot of people do seem to take the "NEC Handbook" as a design spec. To the point of citing things like the outlet in a closet in another post.

Myself, I just couldn't find anything that cited those crimp connectors, but I hate to depend on that given my ability to miss things. Plus, things that are unusual tend to attract attention, and that's not always good just by itself...

 
A comment — “Yellow” implies that they are insulated splices. Part of the product listing is installation instructions—particularly required tooling.

For 10-12AWG insulated connectors, a “dimple” or “5-in-1” stripper/cutter/crimper/fishhook-remover/compass may be marginal for making satisfactory crimps on the described splices.

Crimps are usually sold with insructions that say you use a special tool and some cases also the installer needs some training.
Improperly made crimps are worse than useless.
"Squeezed as tight as you can get them" is seldom the proper method. I guarantee anything made by Amp, has a special crimper requirement.

Yes! I know just what tool you mean. It's $5 at your local hardware store, or free if you buy 50' of garden hose and a set of ginsu steak knives.

This was done with a real crimp tool, the insulation and connetion were crimped at the same time, and there's no insulation damage at all. Looks like a piece of OEM equipment, except it's in a box in a building. The quality was more of a surprise than the connector.
(edit - spelling)

[This message has been edited by tomfcr (edited 01-02-2005).]

I don't mean to hijack this thread, but the title seemed suitable for a question I have.

Is it legal to use non-insulated crimp connectors (the spade/fork variety) to attach stranded wire to the ground screw of receptacles and switches? If so, I assume it is also okay to use the insulated type for side wired switches. These are 3M brand connectors, being crimped with the Klein red & black handled crimping tool. I don't think they make that particular tool anymore, but it is just like the Klein #1006 . I guess I should get rid of that tool and get the 1005 for both the insulated and non-insulated connectors. Thanks.

Roy

Remember that the US NEC requires that "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." If the instructions on the package that bares the listing mark specify a crimper than you must use that crimper. As long as the connections you are talking about are installed within the limits of the listing or labeling I can't see any problem with using them.
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Tom Horne

I had this exact problem 2 years ago. You need to go beyond the package and read the actual UL listing. In my case, I was using a connector that named a crimping tool by model and number to use for the crimps. The chief said he would let it go this time if I would purchase the "correct" crimper for the next use.

OK how many of us here have used those butt connectors when installing a ceiling fan with a downrod longer than the conductors supplied with the fan???

I have rewired the fan with longer wires the few times I have had to.

I have never done this ;-)
but when I did I figured out it is better to stagger the wire lengths so the splices are at different spots in the tube. That is really a good idea whenever you are doing any kind of "inline" splice. It makes the bundle smaller and minimizes the chance of shorting between conductors.