ECN Forum Forums General Topics of the Trade General Discussion Area Why not 2 grounding screws on receptacles?

All-

If you are wiring a series of outlets, and are allowed to use one set of screws for the line, and one set for the load, why do you have to pigtail the ground? I understand the ground screw is only rated for 1 conductor, so why don’t they make outlets with 2 ground screws? Wouldn’t this make for a safer connection (eliminating a possible weak connection with a wire nut?)

Thanks,

Chimo

See 250.148. The continuity of the grounding conductors shall not be interrupted. First ground the box, then ground the receptacle to the box, so that removal of the receptacle willlnot interupt the grounding circuit.
Creighton.

If you are talking about a duplex receptacle you might think about it this way. Your wiring two individual receptacles and have the option to break the tabs to either half switch or wire with two different hots. Or, to break off both tabs and wire with two individual circuits / neutrals. either way your only grounding one strap or yoke.

Grounding is so important that it cannot depend upon the device for it's continuity. Like Creighton said, first the continuity of the ground is assured, then you bond the receptacle to the grounding system via pigtails or jumpers. By the way, a wire nut is a superior connection, in my opinion. Although either, done correctly, is an excellent connection.

Now I understand, continuity is the key. Which brings up one more question- In a duplex config., why only allow 1 conductor under the ground? If the grounds were twisted together, you would maintain continuity if the outlet was removed. Is it just a matter of solid contact between the wires & screw?

The basic rule is one wire per terminal, so that limits you to one wire under the screw. This rule applies to all terminals, not just equipment grounds.

Twisting the wires together is not recognized as a splicing method, you have to finish the job with a splicing device (such as a wire nut) or brazing, welding or soldering.

We pigtail all conductors, I thought that everyone did. It is not considered code compliant to run the full ckt. current through a device strap.

I don't know the code reference off the top of my head but that's the enterpretation here in Nebraska.

GJ

GJ,
That will be news to UL as the listing says that you are permitted to use the device to splice the circuit conductors.
Don

I too splice all conductors, UL listed or not. Personnal quality / prefferance. (Not saying that those who do use the device terminals perform lesser quality work.) But I would have a kiniption if one of my guys does it, as I feel it sooner or later may become a call back for warrantee. And, I would defininatley hit the roof if it were done on a 3, or 4 wire circuit. This could subject the circuit to under/over voltage should the neutral fail. And, that may also be a code requirement for the 'grounded conductor', as well as the 'grounding conductor'. (I'm on my other computer and can't check now.)

Pigtail is required for the grounded conductor if part of a multiwire circuit.