I may not have made it clear. I know about the screws where the 3 wires go.
It is the screws that mount the receptical to the box I have the question
I have not bought any in many years and just noticed a week or so ago they
started putting some brass or copper keepers on only one end to hold the
mounting screws to the end of the receptical. The other end is still plastic
or paper. They may have started doing that 10 years or so ago, I don't
know when it started.
I did dig out some recepticals and a light switch that I have had for many
years and they had the special keeper on one end. Also had some that just
had the plastic keepers on both ends. Guess that I never noticed that.
before. All I could recall just had the plastic on both ends. I can see
where the plastic could sort of insulate the frame/ground connection.
Most of my work was in electronics and 3 phase wiring. Never did very much
with the 120/240 circuits other than just enough to know which wire to hook
where to keep the neutral and hot on the correct side. Did not have to know
the code for most things.
On Wed, 25 Nov 2015 18:21:11 -0800 (PST), Uncle Monster
You can't be talking about the code inspector so I am guessing someone
in your IT department still has a leisure suit in the closet.
It was determined decades ago that IG did nothing to make computers
work better and compromised surge protection.
You want as much bonded together as you can get with as short a path
as you can get. The IG made the ground too far away to do much in a
serious transient event like a nearby lightning strike.
On Wed, 25 Nov 2015 19:18:07 -0800 (PST), Uncle Monster
I was around for that, we were using braided ground straps on every
floor post and ferrites on anything that wasn't grounded. The thought
was very short ground paths and ferrites to slow down the signal long
enough to slow down the transient in the signal lines until it was
shunted out ... or some such thing. Whatever it did work for esd and
common mode transients.
When we finally analysed the "noise" we identified the enemy and it
The noise was not external at all, it was coming from 100-200a switch
mode power supplies in the mainframes.
The next generation of machines (30xx and 43xx) had quieter power
supplies and all of that stuff went away (circa 1980 or so).
A few years later we took that "short ground path" stuff out of the
glass house and into the hinterlands to protect all of those little
machines you see in "retail" from lightning (banks, hotels,
restaurants and stores)
We had people plugging their terminals in regular outlets and using
the IG for the operator's space heater.
We were telling people
On Wed, 25 Nov 2015 10:30:48 -0500, "Ralph Mowery"
That is a "self grounding" receptacle and could legally be installed
in a grounded metal box without using the ground wire terminal on the
device. It is still a good idea to use the wire tho.
These are handy if you are retrofitting a 3 prong receptacle in a box
that was grounded but still only had the 2 prong devices installed.
(somewhat common for a while in the 50s)
On Wed, 25 Nov 2015 11:11:12 -0500, firstname.lastname@example.org wrote:
Yes, this is the correct answer. The "self grounding" outlets cost a few
cents more. They are a good idea, but I agree to still use the ground
wire where possible. Personally, I'd just make all of them with the self
grounding device and eliminate more clutter on the store shelves. For
the manufacturer, the cost to add this, cant amount to much of anything.
Of course if there's plastic or bakelite boxes, this does nothing.
It's not really a "keeper" but, rather, serves to ensure electrical
contact from the *metal* frame of the switch/outlet *through* the
screw and into a (metal) Jbox.
Some idiot replaced a "three-way" switch in the garage with a regular
light switch. Seeing three terminals on the switch (the third being
the safety ground!), he assumed the third wire ("traveler") should be
connected to that screw! Had me puzzled wondering why I caught
a shock "only sometimes" when TOUCHING the switch/plate!
Had the house been wired with metal Jboxes instead of plastic, this
wouldn't have happened (a breaker would have blown whenever that
traveler ended up with line potential!)
A good reason why people who lack the knowledge should NOT be allowed to
touch electrical wiring!!!
Also one of the reasons why I use ONLY metal boxes. I will admit that I
used metal boxes all my life, so it's probably an "old age" thing, but I
feel that metal boxes are safer as far as grounding, and also a little
safer if something in the box overheats, since plastic burns whereas
metal dont. Not to mention that the screw holes in plastic boxes tend to
strip out, and once that happens the box has to be replaced, which
likely means ripping walls apart. Whereas, if the threads strip in a
metal box, one can just rethread it for a thicker bolt or use a sheet
It never fails to amaze me what some can do.
At work a receptical on a ground fault breaker would trip with any load.
Some other workers had tried replacing the breaker and it still tripped with
To make a long story short, the wires went from the breaker box to another
box with terminal strips in it. Some one had used the wrong neutral going
to the receptical. One of the workers (he did have a state license) would
just pick up any neutral when doing the wiring.
If I could help it, I would not let him change a battery in a one cell
flashlight from some of the things he did at work.
I consider "basic electricity" (not to be confused with detailed Code
requirements) to be a "no brainer". But, apparently, there are lots
of DIY'ers who *have* no brains! Too many people who *think* they
know what they are doing...
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