Grounding an older electrical box

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Theodore

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I'm running some new MC cable into an older (1950's) metal electrical box that has AC cable (more commonly called "BX") in it. The box doesn't have a grounding screw to attach to, and none of the existing holes in it are tapped such that I can attach a grounding screw.

Is there any alternate NEC-compliant method to attach a ground to this box, or must I replace the box? I heard about grounding clips, but not sure if they're ok with the code.

Thanks
Theodore
 

Reach4

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Your outlets with a green screw connect that green screw to the mounting tabs. Those will connect to the metal box. So it seems to me, that will do what you want, right?
 

Jadnashua

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In a perfect world, screwing in a receptacle or switch to a metal box would provide a reliable ground, but in the real one, it doesn't. Many of the prefabbed ground wires come with a fairly big sheet metal screw. What are you using to try to attach to the metal boxes?
 

Jadnashua

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Duplicate....many ads on this site do not have valid security certificates, and my AV program doesn't like it, so it tends to create double entries when I tell it to ignore things. This all started when Terry added video ads to his site.
 

Cacher_Chick

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When i am doing work in old metal boxes, i drill and tap the holes so that they accept the screws. Every box must have a ground pigtail fastened with a machine-thread screw.
 

Speedy Petey

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Your outlets with a green screw connect that green screw to the mounting tabs. Those will connect to the metal box. So it seems to me, that will do what you want, right?
Not sure what you mean by "connect that green screw to the mounting tabs", but this all sounds wrong.

A metallic box MUST be grounded (bonded to the equipment ground) somehow first and foremost. Simply screwing a receptacle to a box DOES NOT ground it, unless the receptacle device is listed for that purpose (known as self-grounding).
 
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