chris kennedy
Senior Member
- Location
- Miami Fla.
- Occupation
- Retired electrician
What's the reason they left the extra clamp in the box to possibly ground out the black conductor. :roll:
Thats for box fill calcs, demonstration purposes only.
What's the reason they left the extra clamp in the box to possibly ground out the black conductor. :roll:
I've wondered if it is acceptable to remove the non used clamp based on the fact the install instructions doesn't state you can. I do when I need the room , like with a GFCI receptacle.
Do-able for the hammer handle method . . . in my area, most of that era's boxes are 2x3x2.5 and from Table 314.16(A) that's only 12.5 cubic inches. One is limited to three K&T conductors, two BX conductors, or two NM conductors. All too many of of the situations given to us from that time have more than that.Just might make it doable in some of the old 1920's houses with small boxes
I've wondered if it is acceptable to remove the non used clamp based on the fact the install instructions doesn't state you can. I do when I need the room , like with a GFCI receptacle.
I allways take the unused clamp out, more room for the wires:roll:
If the instructions don't say you can't, you can, and I have.I've wondered if it is acceptable to remove the non used clamp based on the fact the install instructions doesn't state you can. I do when I need the room , like with a GFCI receptacle.
If the instructions don't say you can't, you can, and I have.
I've even re-used the same screw for the EGC.
boxes are 2x3x2.5 and from Table 314.16(A) that's only 12.5 cubic inches. One is limited to three K&T conductors, two BX conductors, or two NM conductors.
The EGC not being attached to the box is another thing.
I'd like to know where they got the funky tape measure that goes from 7 back to 1? Had to be a woman art director, because a man would have made it go from 4 to 7. :grin:
The receptacle has the grounding clip on the yoke. I have never understood why it's allowed to ground the receptacle, but not the other way (receptacle grounds the box).
IMO it is because they do not want the removal of the device to interrupt the grounding of the box.
That is the reason no device comes with two grounding screws as well.
Does it need to be?![]()
IDK ,But look at 250.148(C):roll:
Go to the ground screw manufacturer's web site and see if you can find a plain old ground screw that is "listed". The plain old screw for grounding is in a class by itself as it doesn't have to be listed, it can be listed, but it doesn't have to be listed.250.148 Continuity and Attachment of Equipment Grounding Conductors to Boxes.
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(C) Metal Boxes. A connection shall be made between the one or more equipment grounding conductors and a metal box by means of a grounding screw that shall be used for no other purpose, equipment listed for grounding, or a listed grounding device.
Go to the ground screw manufacturer's web site and see if you can find a plain old ground screw that is "listed". The plain old screw for grounding is in a class by itself as it doesn't have to be listed, it can be listed, but it doesn't have to be listed.
The red highlight in my quote above is a complete item and does not contain the word "listed". "Equipment listed for grounding, or a listed grounding device" are two more ways that the metal box can be connected.
I thought that in one of the older code books that the code required ground screws to be listed .