What is it...?

I guess we all have an unanswerable question....so here is mine.

I am on a commercial job using premium grade receptacles, the kind with the screw-tightened wire clamp for the hot and neutral (so you can use stranded wire easily). Having used those properly, I find that the ground screw is a puny green screw, self-tapped into the frame of the receptacle. I find myself thinking that somewhere it must be written that a ground screw cannot have a wire clamp like the line and neutral screws. I think that, but I would sure like to read it for myself.

The mystery deepens when I install some twist-lok receptacles and lo...the ground screw does indeed have a clamp, identical to the line and neutral.

So I wonder....who is the terminal god? and where has he written that a ground screw cannot have a wire clamp?

And, in my incredulity, I have the obscene thought that the lack of a wire clamp on a premium wiring device is a cost-saving measure agreed upon by the manufacturers of these devices who have NO clue as to the needs of those who install these things by the millions out on the job. That just could not be....impossible.

Is there anyone...who can shed light on my terminal dilemma?

Reply to
User 1.nospam
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They may be thinking that you will be using a solid wire pigtail in the regular devices. It is certainly a money vs need question though.

Reply to
Gfretwell

It's probably a self-grounding type - with the clip on the 6/32 device screws. Since commercial jobs require metal boxes (usually 1900), you're not going to need that ground screw. Therefore, why waste money on a clamp type terminal.

Reply to
Nukie Poo

Reply to
Phil Munro

Virtually all spec jobs, institutional, government, large commercial require a separate grounding conductor. The specs will read "metal conduit grounding path is not acceptable."

Reply to
User 1.nospam

True, but that is labor intensive (ie, expensive), and why have the clamp on the line terminals if you are going to use a crimp spade....?

Reply to
User 1.nospam

That really is the heart of the matter..."they may be thinking". My brother attended a trade show in NYC a few years ago and attended three days of seminars. One day was for manufacturers, one day for distributors and the other day for contractors. His conclusion, having heard the three discussions was, "There is very little communication between the parties."

When Disney develops a new ride or attraction for their parks, they invite at least two small children, 5-7 yrs old, a couple of teens, a couple of parents and a couple of retirees, to get an accurate evaluation and valuable suggestions for their venture. I wonder how many hands-on mechanics have had their say in the electrical manufacturing sector?

----> end of rant. :)

Reply to
User 1.nospam

No sh*t, Sherlock. And just what must be done in every box with that grounding conductor? It gets bonded to the box, thus making a jumper to a self-grounding receptacle device unnecessary. BTW, if you reread my post you'll see I made no mention of conduits as grounds; I stated that metal boxes are used in commercial jobs.

Reply to
Nukie Poo

You are making a mountain out of a mole hill. Just do the job and quit quibbling.

Reply to
Brian

Really? (honestly I don't know). I thought one had to do a pigtail to both the box and the outlet! Obviously in a plastic box one has to wire to the receptacle, though in ganged boxes it would be much easier to do it once to the box. That's one reason I didn't use metal boxes when I built my garage some years ago. ...too much work! ...not that I'm likely to do any wiring job big enough to matter anymore.

Reply to
Keith R. Williams

Questions like this intrigue me. My thought on this is, what if you where to apply the derating factor to your wire for the number of conductors in the conduit IAW NEC table 310.15(B)(2)(a). OK so let's say I have six 20amp circuits running in the conduit to feed "X" number of receptacles, and I see for what these receptacles might be used for, all pull near they're maximum at all times, set up all in a row along the conduit run. So now let's say that if you do apply the derating factor then on these 20amp circuits you would have to install 10AWG wire for your hot and neutral. 10AWG is not easy to bend and clamp behind the screw head. So maybe?? the reason for the clamp? As far as the ground is concerned, 12AWG is still only required for

Reply to
Maintech

There is no place where it says how something must be clamped. The code would always refer to it as "suitable device tested by a competent authority," or some such laungage.

They also have them on male and female cord caps.

Nowhere. I am sure you will find them out there if you tried hard enough. My guess is that there isn't much room at all for what you are asking for. It's easy to make the "screw-tightened wire clamp" on the sides compared to the end where the ground is.

It makes no difference one way or another to me. Use a crimp type connector with stranded when using a screw. I know some people twist the stranded wire tight together and connect it that way, but I don't like that and will avoid it except when necessary (like when I'm buying them ;-> They can get expensive if you don't watch out what you are getting.)

To put it bluntly it's called the economics of an industry. Most electrical devices haven't changed much in decades. One reason is because the people who buy the devices aren't the ones installing them. All they see is a percent savings over another item that will do just as well. The cheapest items are what everyone else is buying. Hence, you get into a vicious cycle of bad products surviving over better ones.

The savings in the field may be great using better devices but it's very difficult to factor economically. Your employer is going to accept evident production values over much more obscure ones like buying receptacles that make you happy.

Reply to
Zzzap

The only thing I don't like about this idea of using a crimp connector is that it gives another point for a system to fail if not done right, i.e. now you have two connection points that could be bad where as if you take the wire straight to the terminal there is only one connection point that might fail, this was my idea of the origanal post of why provide clamps on preminum recepticals. I once had a new machine from the U.K. that they used a lot of crimp terminals and being in Maintenance found that alot of those little 18AWG wires didn't make contact in the crimped side. Once again Just food for thaught.

Reply to
Maintech

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