Replacing Electrical Outlet

Hey TW Electricians!

I'm in the process of redoing some rooms in my house (new Windows, paint, trim, etc). The house was built in 1964. The electrical outlets are 2 prong and I was wanting to change out to 3 prong. I pulled out one of the outlets and I see wire with neutral, hot and ground. But only the hot & neutral are connected to the outlet. The grounds are twisted together in the box. Oh, the box is metal. I don't see that they're connected to the box in any way.

I've read that the metal box could be grounded. I used my outlet tester and touched the cover plate screw (per Google) with one prong and had the other prong in the smaller slot and I didn't see the light come on. This leads me to think the outlets not grounded at all?? That doesn't seem reasonable though.



Can I simply install new outlets and connect the hot, neutral & grounds and be ok?

I thought if the box was grounded, I could run a pigtail from the new outlet ground to the box.

I'm not opposed to calling an electrician, but I'm pretty handy and don't mind doing my self.

Any guidance is much appreciated.

Mark

 

So I just checked my panel and all of the ground wires from the house return to the box and are all twisted together and are attached to the box in one spot (lower right corner). I see a big copper lead coming from that connection...looks like it goes to the exterior.

So it seems the 2 pronged outlets and boxes aren't grounded (makes sense with only 2 prongs). But the system is grounded.

Now I'm thinking I'm safe to simply to connect the ground wires in the outlet box to the new 3 pronged outlet.

Do I still need to ground the metal receptacle box?

 

Was the receptacle screwed to the outlet box when you did this test? If not, there would not have been a path for ground. Regardless, per NEC requirements, you should ground all metal electrical boxes.

http://ecmweb.com/qampa/code-qa-attachment-equipment-grounding-conductor-box

 

Yes, it was attached.

 

I believe I can connect the ground wires in the box to the box with a new ground screw and then run a ground wire (those premade ones with the screw) from the new outlet to the box. I have those two screws available (as seen in the pic).

That would be the proper method based on further research.