Receptacles -- # of wires per screw

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On 2/10/2009 11:26 AM RBM spake thus:

>>>

Pretty much 6 of one and half a dozen of the other, isn't it?
Besides, by using the clamps, you'd reduce the volume of stuff in the box by cutting down on the number of wire nuts, which take up space.
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That's true, but a lot of those clamps don't work particularly well with solid conductors. Wire nuts installed correctly stay tight

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I do not know which clamps you are referring to but that does not reconcile with my experience in thirty three years in the craft. The screw tightened clamps I have encountered have been fine on both stranded and solid conductors and work better on stranded wire then any screw binding connection without clamps ever would.
-- Tom Horne
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I do not know which clamps you are referring to but that does not reconcile with my experience in thirty three years in the craft. The screw tightened clamps I have encountered have been fine on both stranded and solid conductors and work better on stranded wire then any screw binding connection without clamps ever would.
-- Tom Horne
And in my thirty seven years in the business, I've found clamps work great on stranded conductors, but on some devices, such as Leviton GFCI outlets, the clamps are not nearly as secure with solid conductors
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On 2/11/2009 4:27 AM RBM spake thus:

I've used those same outlets and have never experienced any problems securing solid wire (#12 or #14) to the clamps. What specific problems have you had?
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The problem is, that after tightening, the wires come loose when pushing the outlet back into the wall. They don't always come loose, but of the hundreds of these things I've installed, too many do come loose. Conversely, of the thousands of outlets I've installed with screw tight connectors, I've never had one come loose

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This seems correct. I always learned that the fallback for things is the "Authority Having Jurisdiction". The NEC usually acts as the AHJ, but if something is not specified by code (NEC or local), the AHJ is usually the manufacturer. If they intended two wires to be clamped, the device would be so designed and labelled.
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No, the grounds are bare so it is easy to twist them together in the back of the box and cut one off short. Then you hook the remaining wire over the single green screw and tighten it down.
For fixtures where you "need" to connect two wires to a single screw, take a short length of same-colored wire and bug it on to the two wires as a pigtail using a crimped Buchanan connector or a wire nut.
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snipped-for-privacy@rochester.rr.com wrote:

I assume that you mean twist them together using a wire nut (such as a green one with a hole in the center), since just twisting them together without one doesn't meet the code.
Also, if the wire that is cut off short leaves it with less than 6 inches of wire in the box, that would not meet the code requirements.
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This last statement is untrue. The code requires six inches of wire in the box and extending at least three inches beyond the opening of the box "for splices or the connection of luminaires (fixtures) or devices." The code does not require that the conductors be that long after the splices are made up and the devices installed. Requiring that would overcrowd many boxes and cause more problems.
-- Tom Horne
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Tom Horne wrote:

Do you have to know where it says that in the code? I'd be interested in looking that up and reading exactly what it says. Thanks.
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Oops, I meant to write, "Do you *happen* to know where it says that in the code?"
RonABC wrote:

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RonABC wrote:

300.14
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Tom Horne wrote:

I think you may be misreading what the code says and you are incorrectly concluding that, after the splices are made, the length of conductor rule no longer applies. The requirements are under 300.14, and then it says:
"Exception: Conductors that are *NOT* (emphasis added by me) spliced or terminated at the outlet, junction, or switch point shall not be required to comply with 300.14."
In other words, conductors that *ARE* spliced or terminated at the box do have to comply with 300.14 even after they are spliced or terminated. Only the unspliced or un-terminated-at-the-box conductors do not have to comply.
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Ron I was not basing my position on the exception bout on the wording I quoted in my reply. Two different boards of appeal that I know of have come down in the same place. I know of no contrary formal interpretation. I'll quote the whole section so that those without ready access can follow the discussion.
"300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points. At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires (fixtures) or devices. Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening.
Exception: Conductors that are not spliced or terminated at the outlet, junction, or switch point shall not be required to comply with 300.14."
My position, and the position of the Virginia state board of permit appeals, is that the six inches of free conductors is required in order to have enough wire to make the splices and connections during make up and not forever afterward.
-- Tom Horne
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wrote:

Ron I was not basing my position on the exception bout on the wording I quoted in my reply. Two different boards of appeal that I know of have come down in the same place. I know of no contrary formal interpretation. I'll quote the whole section so that those without ready access can follow the discussion.
"300.14 Length of Free Conductors at Outlets, Junctions, and Switch Points. At least 150 mm (6 in.) of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires (fixtures) or devices. Where the opening to an outlet, junction, or switch point is less than 200 mm (8 in.) in any dimension, each conductor shall be long enough to extend at least 75 mm (3 in.) outside the opening.
Exception: Conductors that are not spliced or terminated at the outlet, junction, or switch point shall not be required to comply with 300.14."
My position, and the position of the Virginia state board of permit appeals, is that the six inches of free conductors is required in order to have enough wire to make the splices and connections during make up and not forever afterward.
-- Tom Horne
That's all fine and well, but it would really be helpful if in the future, you preface your replies to indicate that you're quoting some particular entities interpretation of the NEC
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wrote:

And furthermore, what business does the state of Virginia, or any other state, have to interpret National Electric Code? They have the right to use it, or not, they can make their own code if they choose, but the NFPA, the people who write the NEC, have panels of their own, who you can write to, to have any section of code interpreted. How arrogant that would be for someone to believe that they can interpret something better than it's author.
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I read that as 'Twist bare ground wires together place the twisted section under screw of the metal box and then use one of the wires to connect to the duplex'.
Unless the outlet is being 'split' (For say an Edison circuit or to switch one of the hots of the outlet) there is provision on a typical duplex to terminate two white neutrals and two black live wires. Other than that pigtail them. And yes I prefer a good quality duplex that has those terminals that trap the stripped wire end under a metal plate as screw is tightened down.
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Are you saying that when you need to connect two wires to a screw, what you do is pigtail THREE wires together, and then that third wire, the new, short one, and hook THAT one to the screw?
Thanks,
David
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David Combs wrote:

Exactly, you got it. and if the box happens to serve two directions then you have four in the nut counting the pigtail.
steve
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