ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Wirenut techniques

'66,

I think this is a "to each, his own" type of thing. As long as they're tight. With pre-twisting I can see it before it gets covered by the wirenut, I don't have to guess how much to twist the wirenut

Maybe others can comment on different types' instructions as to pre-twisting being required/recommended?

BTW, nice display, but the Tools are crooked

P.S.
Looks like the Linesman's could use a dab of insulation on the bottom left handle.


Bill

Can you tell which one is which?

actually, i can't...

I thought "back-wired" meant that the screw plate tightens the connection like GFCI recepts...

I stand corrected, thanks

I think the top pair was pre-twisted. Actually, they look identical. If I'm right, let me know and I'll let you know why I GUESSED the top!

If I had to guess (no Lifelines left) I would say that the top (longer wire) was pre-twisted.

Bill

I just wanted to show that my technique is equal or even superior to pretwisting and hand tightening...


I only use them to drive the occasional staple in tight spots... My strippers are my cutting tool, since they're cheapest to replace...(I generally buy one pair a month to keep 'em sharp...)
Kind of a sentimental old tool too I guess....

I'll give some more time for others to guess...

Consider this:

When pre-twisting, the end inserted into the wirenut is larger, and therefore starting out further back in the wider area of the spring. It gets tight sooner, not allowing full contact with the wires (hence only three scratches).

With using the wrench and not pre-twisting, the end is inserted further up into the narrow part of the spring, as it tightens to maximum torque-vs-maleabilty, the wires get twisted very closely to the points of contact, creating more of a solid mass for current path and heat transfer. (Hence 9 scratches and tighter "weave")

Splices are the weak link... Make them as "strong" as possible...

As far as Wagos and the like, having a Cu to Brass to Cu connection that is merely "sprung" into place, (as apposed to screwed or twisted) is just a very bad idea in the weak link of our trade.

Later, I'll tell you the story of why I'm so anal about this...

[This message has been edited by sparky66wv (edited 08-28-2001).]

Having started all this, I guess I should throw in my 2-cents worth.

I'm not used to seeing wire nutted connections, but I would guess that the longer (top) connection was pre-twisted. I can't see the actual Cu-Cu connection too clearly, but I'm going on the twists farther back along the insulated part of the wires.

Back to the definition of back-wired:
I've never seen the terminations on one of your GFI recepts. so I'm still a little unsure on this point.

I do have a box full of U.S. fittings here, including several hospital-grade 5-15 singles. It appears that if a wire is clamped on one side of the screw, it can emerge straight back or be bent out to the side. To fit under the plate on the other side, though, it would have to be put in through a hole in the rear of the molding.

I figured it must be something to do with this, but now I'm confused.

In back-wired recepts the screw and backplate still provide pressure for the termination, rather than an internal spring/catch. But they will look similar in having holes in the back to insert the wires.

GFCI's usually have provisions for two back-wired conductors per screw.

These are considered quite dandy in my opinion whereas backplugged (spring/catch type) are not.

Have to agree with you there. Maybe I don't have enough experience of the push-in terminations to really comment, but I just don't like the idea of such a light form of connection carrying 15A.

By the way, our fittings all use screw connections, though not of the same type as yours.

Pardon me while I attempt to "tie" the two "threads" back together again...


You make valid points... I've examined the very WireNuts I used for the demonstration and found no visible damage to the springs... They both looked new...

Ideal Wire Nuts have a square cross-sectional-shaped spring (for better grab) and is imbedded in the housing for maximum support. I'd say one would split the side at the same moment the spring deformed.

B-Caps an the other hand are loose and floppy and never seem to get tight no matter how many times I twist them... I've pulled springs completely out of 'em before...Cheap.

My technique also only takes about 20 to 30 seconds, where pretwisting adds about 20 to 30 seconds to the procedure. Assuming the outcome is equal... it is twice as fast.

Right now I have no WireNut boxes (you know, they may no longer say "no pre-twisting required" but they did at one time...) Mine usually go straight into the "tackle box"...
The wrench is being used within the guidelines given by the manufacture of the tool and the WireNuts... I can't find a copy of it either...

Tom, you got any help here?

Oh, and as far as me saying to crank them until they almost break, etc.

I tend to "exaggerate for clarity" which is sometimes neccesary in this sensationalized world... In telling someone to "Crank it until your wrist hurts" I hope to at least get half of that torque out of it!

Tell them "finger tight" and they'll just be barely snug...

One man's "snug" is another man's "tight"...
(And probably "loose" in my opinion)

Having actual torque specs would be nice... No luck in my googol of google searches...

[This message has been edited by sparky66wv (edited 08-28-2001).]