Adding grounds to existing outlets

[Irving]

My house was built in the before outlets were grounded and most of the house has old receptacles. I'm under the impression (from an electrician I had out to do a job that was over my head) that I can simply change the receptacles and run a ground wire down into the existing box. As part of the job I had the electrician out before, he grounded all the outlets in my kitchen this way. He had mentioned that there was a grounding block in the attic and said I only had to run the ground wire to that box, saving myself the hassle of trying to run everything into the box outside. Can someone confirm this for me? Also, and this may be a dumb question, but could I theoretically ground all the outlets in each room, connect them all to a single ground wire, and run one wire from each room to the grounding block? I don't know a ton about electrical, so I don't know if this is a dumb question or not. Let me know if this doesn't make sense and I need to clarify what I'm asking.

[asmo]

Insert St. Elmo's Fire picture here.

Not an electrician so I'm not going to provide any useful commentary. But generally, multiple ground points are a bad idea.

[Irving]

When I first envisioned this project, I was thinking I'd have to run a ground from each receptacle out to the box, but it should be one ground per circuit out to the box right?

From looking at the work of the electrician, that appears to be what he did, as he only grounded one circuit.

[Big E3]

I have not done this in a long time. But generally speaking the white wire is a ground and when they added the third wire it was also a ground. Both the original second white wire and the new third ground wire attach to the same ground block in the main box. I have seen an electrician pigtail the third outlet post and the metal box to the original second white wire in a two wire system at each box. Back when they added the third wire on outlets they essentially were just grounding the appliance being plugged in and the metal outlet box with the third wire. Having said all that I'm not sure anything I said is code compliant.

[Wulf202]

Yea you just add a wire per circuit

[Big E3]

Not sure I was clear. The old two wire system consisted of a black hot wire and a white ground. The new three wire system consists of a black hot wire along with white and bare ground wires. So knowing that you still have only one hot wire and the rest are grounds should help. Understanding this it helps you to know why tying all the grounds together will work. My dad did this to a house when we moved into it in 1966, the house is still in this configuration and working fine as a rental. The third ground is just redundancy. The original single ground is capable of handling all your grounding needs.

[Irving]

Funny thing, I see original wiring running through attic and it actually has three wires, and the ground is just pinned back.

[MED]

I have this issue with my rental property. If you run a separate ground wire, it is considered a code violation. There are only three options that meet code. Either use a two wire receptacle or use a GFCI at each receptacle with a sticker that states no equipment ground. Third option is to put in a new three wire run where a ground wire is needed.

If you don't care about code or resale, then you can add a ground wire per circuit back to the service panel. However, you need to make sure that there is a ground between all the receptacles and switches on that circuit, or more crudely, add grounding wire to the main house ground for each receptacle or switch. Either way, it would never pass inspection when you try to sell the house. I can't believe a licensed electrician would do either.

[Irving]

Hmmm, I'll have to check code in my area. Thanks.

[SideShow Bob]

According to the 2014 NEC, you can do this.

PM on the way.