250.148

[Dennis Alwon]

What does (C) mean.... I am trying to think what other purpose could be used?

250.148 Continuity of Equipment Grounding Conductors and Attachment in Boxes.

If circuit conductors are spliced within a box or terminated on equipment within or supported by a box, all wire-type equipment grounding conductor(s) associated with any of those circuit conductors shall be connected within the box or to the box in accordance with 250.8 and 250.148(A) through (D).

Exception: The equipment grounding conductor permitted in 250.146(D) shall not be required to be connected to the other equipment grounding conductors or to the box.

250.148(A) Connections and Splices.

Connections and splices shall be made in accordance with 110.14(B) except that insulation shall not be required.

250.148(B) Equipment Grounding Conductor Continuity.

The arrangement of grounding connections shall be such that the disconnection or the removal of a luminaire, receptacle, or other device fed from the box does not interrupt the electrical continuity of the equipment grounding conductor(s) providing an effective ground-fault current path.

250.148(C) Metal Boxes.

A connection used for no other purpose shall be made between the metal box and the equipment grounding conductor(s) in accordance with 250.8.

250.148(D) Nonmetallic Boxes.

One or more equipment grounding conductors brought into a nonmetallic outlet box shall be arranged such that a connection can be made to any fitting or device in that box requiring connection to an equipment grounding conductor.

 

[electrofelon]

It means that a screw used to mount the box or for a clamp can't also serve as the EGC connection.

 

[infinity]

What Ethan said. Quite often you would see the EGC wrapped around the clamp screws in a device box.

 

[Dennis Alwon]

Ah, got it. I was thinking the ground screw and trying to figure what other purpose it would be used for.

 

[electrofelon]

What Ethan said. Quite often you would see the EGC wrapped around the clamp screws in a device box.

My absolute favorite, the EGC wrapped around a drywall screw used to mount the box, hanging on for dear life.....

 

[readydave8]

My absolute favorite, the EGC wrapped around a drywall screw used to mount the box, hanging on for dear life.....

That's my 2nd favorite

Favorite (seen it more than once):

Keyless in non-metallic box, end of run so only one bare wire

Wrapped around the screw that holds keyless to box

 

[blkmagik21]

That code reference is why we tie all grounds together during the rough in. Here it must be done before cover inspection.

Also some people would put two wires under the ground screw of a device and if the device is removed the EGC continuity is broken.


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[LarryFine]

Also some people would put two wires under the ground screw of a device and if the device is removed the EGC continuity is broken.

Some receptacle lines used to come with two grounding terminals.

 

[blkmagik21]

And it’s a good reason why “used to” is a key term lol


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