Installing ground screw in a box with none

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Old 01-19-10, 04:56 PM
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Installing ground screw in a box with none

I have multiple switches and outlets I'm changing due to age and cosmetic color change. Many of them are grounded through the metal box, but not to the outlet. As I'm changing them, I am correcting the situation by wirenutting the incoming ground along with a wire to the box and a wire to the outlet ground. In some of these metal boxes there is no place for a ground screw. I've searched the internet and have seen some options for remedying this. I'm wondering if there is any one that is particularly good/bad or if they're all fine and safe. I don't want to create a bigger problem than the one I'm trying to remedy.

The three main options I've seen are: drill a hole, tap it, and use a normal green ground screw, drill a hole and use a self-tapping ground screw, or use a screw already in the box that is not being used for any other purpose (e.g. an unused cable clamp). Also, for the self-tapping ground screw I've read that it doesn't have to be the stereotypical green screw (which is good since I cannot find any self-tapping ones) and it just has to have a minimum two threads of engagement.
 

Last edited by DIYnewbie9; 01-19-10 at 06:26 PM.
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Old 01-19-10, 06:34 PM
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Ground clips are available to secure the conductor to the box. Also the clamp screw holes are tapped the same as a regular ground screw, 10-32.

I don't know if a self-tapping screw would grab 2 threads.
 
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Old 01-19-10, 07:43 PM
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Originally Posted by pcboss View Post
Also the clamp screw holes are tapped the same as a regular ground screw, 10-32.
I got excited to read that, but unfortunately it doesn't appear to be the case in my box. I get maybe two twists into the hole before it just stops.
 
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Old 01-19-10, 07:46 PM
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How is the ground wire attached to the box? If the ground is attached correctly to the box, you can use self-grounding receptacles. They are a bit more expensive than the 50cent receptacles, but you don't want to use those anyway. The self grounding receptacle grounds through the yoke screw into the metal box.

It might solve your problem a bit easier than drilling and tapping.
 
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Old 01-19-10, 07:52 PM
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Originally Posted by Zorfdt View Post
How is the ground wire attached to the box?

Currently they're attached to the cable clamp screws which are also clamping cable under them.

Originally Posted by Zorfdt View Post
If the ground is attached correctly to the box, you can use self-grounding receptacles. They are a bit more expensive than the 50cent receptacles, but you don't want to use those anyway. The self grounding receptacle grounds through the yoke screw into the metal box.
The box I'm specifically talking about is for switches, but I assume I'll encounter this problem with the outlets too. I do actually have self-grounding outlets, but it was my understanding the pigtail with a dedicated ground screw was the
 
 

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