ECN Forum Forums Technical Discussion Electrical Theory and Applications Residential Device Termination Best Practice Question

I mailed one of these Zinscos anonymously to NORCAL to horrify him.

[This message has been edited by electure (edited 01-07-2007).]

I must be in the picky minority here because I don't like backs-stab or back-wire receptacles. Even when applying serious torque to back-wire receptacles, I've had the wire come loose under the pressure-plate when I went to push everything into the wall. Consequently, I end up torquing back-wire receptacles twice to guarantee a solid connection.

I've never once had a loose connection with a screw-terminal receptacle so I prefer to use those.

-John

I like the stab ins.

It worked on me Electure!

I still see those evil beasts on some older apartment buildings (and in my nightmares!).

Shame on Zinsco! Shame!

a picture is worth a thousand words, as they say....
https://i73.photobucket.com/albums/i226/zunguzeng/electrical/DSC00906.jpg
https://i73.photobucket.com/albums/i226/zunguzeng/electrical/DSC00911.jpg

We had some other pictures posted in the general forum. The back-stab design is completely sound and actually has very good surface area! The key is that the wire must be STRAIGHT and installed properly. If the wire is kinked or too short or otherwise poorly installed then, yeah, you're going to have a fire risk. Why not post pictures of screw terminals that have been put on backwards or with too loose or a loop, or too short so the insulation is trapped and a poor connection made?
https://www.electrical-contractor.net/ubb/Forum1/HTML/007963.html

Steve Fehr:
Theelectrickid:
[This message has been edited by SteveFehr (edited 03-04-2007).]

If stabs are so good, why do you only see them on the lower quality devices?
The spring is only a single strip and only provides solid contact pressure at that point.
Don

The spring is providing pressure, and holds the wire against the contact area the same way a screw would. The biggest difference is that it provides less pressure; a screw terminal will straighten out a bent wire, while the spring in the stab will merely hold it in place.

If installed properly, there is nothing wrong with a stab and it works fine and dandy and no buildings burn down and everyone is happy. It's if the stab is not installed properly that we see problems- and, unfortunately, it's impossible to inspect and verify the quality of these connections.

My feeling is that the stab is good in theory but unsafe in practice unless very careful care is taken.

The link in Steve's post to my Photobucket Dissection doesn't work, so here's a new one:
https://s29.photobucket.com/albums/c266/Macsignals/Electrical%20Stuff/

For me:
If someone uses them along with saying "Get 'em done NOW NOW NOW!", then I hate them.
If someone actually takes the time to cut the wire off, strip it the right length and stick it in, then OK, I won't argue.

Ian (Screw 'em down!) A.

Steve,
The area of "contact" pressure provided by the screw is hundreds of times greater than the area of "contact" pressure provided by the flat spring.
Don