I had a bathroom light that would sometimes flicker a bit when turned on. Darned back-stab connections. Anyway, ALL of the switch and outlets I examined on that circuit had the ground wire wrapped around the ground screw but the screw was not tightened. The house is around 13 or 14 years old. I bought it 1.5 years ago. Looks like I'll have to methodically go through the house checking, uh, no, tightening the ground screws. Also the outlets were daisy chained via the back-stab connector. Has that ever been allowed?
lbartel:
The "back stab" install was a prevelant method used in our area of NJ. Matter of fact, I even came across a few that had stranded wire shoved in. To the best of my knowledge, it aws OK to Code. NEC states "multi-wire" branch circuits, neutrals must be "made-up"; not the exact word-for-word, but the meat.
My crews are in the habit of "making-up" ALL splices with 'tails for the devices. (Grd, Hot & neut) We do this prior to "rough" inspection. Takes a few "extra" minutes; but we don't get any call backs. BTW, we don't "back stab". Under the screws, twist it right, & make it tight. The only "back entry" we allow is the spec grade devices; yes they cost more, but they are good & quick.
We do primarily comm, with very little resi.
John
I don't believe the loose equipment grounding conductor (EGC) was making your light flicker. A properly wired lighting or receptacle supplied load device will operate fine without any EGC.
I would check those back-wired devices further for the cause of the flickering light.
Ed
Sorry electric-ed, I didn't mean to say that the loose ground was the cause of the flicker. I've seen the back-stab connections go bad, causing intermittent failures. I do have a serious problem with the loose ground in that should there be a fault, the ground may or may not protect the user.
Another light in the house started flickering last night. Loose feed wire on the switch. Reworked all the switches and outlets on that circuit. There actually were some ground screws tightened down.
- les
lbartel,
Even though you might not like them, but I think that "back stab" devices have been and are still OK under the NEC as per the manufactures instructions. I have seen where backstabs have lasted 12 years without a problem. The biggest problem I see with them, is that the installer, doesn't check to make sure that the back stab is all the way in. They push it in for just a little bit, and then after awile, they fall apart.
If everything is properly installed, back stabs should be OK.
One of the biggest problems, I see, is that in time, or even on new installs, the receptacle is not rigidly secured to the surface (wall). Every time a plug is plugged into ( and removed from ) the receptacle, there is a slight movement of the receptacle in the same axis as the stab-in conductor. After many uses of Plugging-in and pulling-out of the male plug, the receptacle back-stab contacts start to have a sliding action with the stab-in conductor, THEN a loose contact is in the making.
Just don't use the stab-in's for a long trouble free installation. ( opinion only ).
The back stab devices are available only for 14 AWG at 15 amps, and use of those types of devices for 12 awg violates 110.3(B).
"Screwless terminal connectors of the conductor push-in type (also known as "push-in-terminals") are restricted to 15 A branch circuits and are for connection with 14 AWG solid copper wire only. They are not intended for use with aluminum or copper-clad aluminum wire, 14 AWG stranded copper wire, or 12 AWG solid or stranded copper wire."check at:
www.ul.com RTRT.GuideInfo
Receptacles for Attachment Plugs and Plugs
[This message has been edited by Joe Tedesco (edited 10-19-2002).]
Interesting comments. Used to be that the hands-down-first-to-die was the device serving/behind the kitchen refrigerator-freezer.
Duty seems to have a major influence in the life of poke-wired connections. Unless you "get" to take service calls on residences a year or five after construction, they almost always seem to have a perfect record.
[This message has been edited by Bjarney (edited 10-19-2002).]
How about the one at the coffee maker? Easier to get at than the frig. "Duty" has a lot to do with it, glad to see someone brought that up. Used to be that the "stabs" where good for #12 (legal) 'till the NEC figured 15 amps is max. Like I said above, make up the splices, put in the 'tails, under the screws, twist it right, & make it tight!
John
I've done a few years service work, doin' house calls... I don't know how meny times so meny problems have led back thoes dang push-in type switches and recpt. The guy I used to work for has threatend to fire his guys if they every use 'em on his jobs. The bottom line is contact area. There is meny times more contact area between the screw head and the wire than there is between that tiny little tab that pinches the wire on push-in connectors. Someone else said this, and I also do it, strip the wires, include a pig-tail, twist them together, use a good wire nut, put on nice and tight. Use the screw connections on the device, connecting the pig-tailed wires... should last a long time if done properly. Like I said... think "contact area". The more, the better. It's just like oversizing wire, more is less. More area, less heat. Less heat, less fire. Or, maybe a little less flickering!
Leviton recommends 12 in/lbs for screw terminals not otherwise marked.
It isn't terribly tight, just tight enough to hold without squishing the wire.
Now for SQ D Breakers at 35 in/lbs, you'll think you're gonna break it before it's tight enough.
Get a torque-screwdriver, some specs, and play with 'em!
Right, Tom?
There are receptacles out there that look like pin back devices, that are good for solid, stranded, 14 ga and 12 ga wires. The device has little clamps inside the receptacle that holds the wire good and tight. They cost more that the plain receptacles, but it might be worth it.
I'm familiar with those.
They're called back-wired terminals (according to the manufacturer's catalogues).
It's a little clamp that tightens over the stripped conductor as you turn the screw.
They're mostly used in the expensive industrial and hospital-grade sockets but shouldn't be confused with that stab-in pressure-lock crap (which I HAAATE because if you goof and have to rip the wire out of the hole, it's distorted the springy metal jaw in there and it will never hold the wire in properly ever again).
A a Colombian-manufactured (Luminex brand)NEMA 15-amp duplex-receptacle I brought back two years ago from my last trip to Colombia also has this type of terminal with the screw and clamp. It holds the conductor quite securely. The quality level of wiring devices currently manufactured down there is quite good, by the way.
It's a bit reminicent of the terminals with set-screws that European wiring devices usually use (instead of the wrap-around screw type terminations we have).
Much easier to use (no wire bending involved). :-)
[This message has been edited by SvenNYC (edited 10-21-2002).]