Expanding off self grounding outlet

Baldar538 · Dec 22, 2022

Hi - I'm trying to add an additional outlet to a circuit in my house. I tested the outlet with a tester, and it showed as correct. The existing outlet is facing the finished part of the basement, but where I am looking to add an outlet is in the unfinished utility room behind the wall. I have full access to the box and everything I need back there, but due to it being unfinished I have to use MC, AC or metal conduit, I can't just use Romex right? The path this needs to take would be easy for MC, but would be a pain to run conduit around for what it's worth.

When I opened up the box though I noticed there was only a hot and a neutral going to the outlet. Since it is passing an outlet test, I'm assuming that it's a self grounding outlet?

I had already swung by Home Depot and picked up a https://www.homedepot.com/p/Southwi...-Assembly-Quick-Cable-Whip-56482401/204804403 for use in the project. As this is MC the sheath cannot be used as ground, correct? I would have to use the green ground wire inside of it?

As the existing outlet doesn't have anything to pigtail on to, yet is grounded, what would be the correct way to wire this?

So - given a box with a two wire outlet which is passing a test for ground what would be the best way to wire one more outlet in the circuit? Because it's passing a test for ground, do I pick up some ground wires like https://www.homedepot.com/p/Commerc...ls-with-Screws-Green-5-Pack-GP128-5/310747594 and attach it to the existing box, then pigtail in both the existing outlet and the green wire from the MC? On the new outlet end of things I would just connect that ground to the green screw on the new outlets and not to the box as the MC sheath isn't a ground path?

Baldar538 · Dec 22, 2022

Baldar538 said:
Hi - I'm trying to add an additional outlet to a circuit in my house. I tested the outlet with a tester, and it showed as correct. The existing outlet is facing the finished part of the basement, but where I am looking to add an outlet is in the unfinished utility room behind the wall. I have full access to the box and everything I need back there, but due to it being unfinished I have to use MC, AC or metal conduit, I can't just use Romex right? The path this needs to take would be easy for MC, but would be a pain to run conduit around for what it's worth.

When I opened up the box though I noticed there was only a hot and a neutral going to the outlet. Since it is passing an outlet test, I'm assuming that it's a self grounding outlet?

I had already swung by Home Depot and picked up a https://www.homedepot.com/p/Southwi...-Assembly-Quick-Cable-Whip-56482401/204804403 for use in the project. As this is MC the sheath cannot be used as ground, correct? I would have to use the green ground wire inside of it?

As the existing outlet doesn't have anything to pigtail on to, yet is grounded, what would be the correct way to wire this?

So - given a box with a two wire outlet which is passing a test for ground what would be the best way to wire one more outlet in the circuit? Because it's passing a test for ground, do I pick up some ground wires like https://www.homedepot.com/p/Commerc...ls-with-Screws-Green-5-Pack-GP128-5/310747594 and attach it to the existing box, then pigtail in both the existing outlet and the green wire from the MC? On the new outlet end of things I would just connect that ground to the green screw on the new outlets and not to the box as the MC sheath isn't a ground path?

Uploading pictures for context. Two of the outlet that passes a ground test but only has two wires.

The other picture is the back of that outlet and part of the path I'm looking to run the new outlet. It should be headed in a similar direction as that piece of coax on the right heading towards me while taking the picture.

(And there were probably better ways to run that conduit in the picture, but that's the previous owners handiwork not mine - maybe someday I'll get to the point it bothers me enough to fix it)