View Full Version : Adding grounds to existing outlets
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.
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.
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.
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.
Yea you just add a wire per circuit
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.
Funny thing, I see original wiring running through attic and it actually has three wires, and the ground is just pinned back.
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.
Hmmm, I'll have to check code in my area. Thanks.
SideShow Bob
12-08-2015, 17:47
According to the 2014 NEC, you can do this.
PM on the way.
Thanks so far everyone, I'll refresh this when I go to tackle this project this winter.
spqrzilla
12-21-2015, 15:25
No, the white is not a ground. Its a neutral which is not the same thing.
No, the white is not a ground. Its a neutral which is not the same thing.
Yeah no kidding! Holy Misinformation Batman!
This ^
In some models, it can be thought of as a ground, but it is not. Even in modeling, it is a virtual ground, and not a true ground.
Do not connect the ground of a circuit to neutral. Unless you want a sparky surprise from your metal waffle iron some day.
SideShow Bob
12-21-2015, 17:48
This ^
In some models, it can be thought of as a ground, but it is not. Even in modeling, it is a virtual ground, and not a true ground.
Do not connect the ground of a circuit to neutral. Unless you want a sparky surprise from your metal waffle iron some day.
Talking from experience there J ?
Bet you experienced the "Old Butter Knife in the toaster" too.......
laportecharlie
12-21-2015, 19:39
According to the NEC, the white or neutral wire is the "grounded" wire and the green or bare wire is the "grounding" wire. They are not interchangeable.
Talking from experience there J ?
Bet you experienced the "Old Butter Knife in the toaster" too.......
Degree in Electrical engineering count? I've taken my share of zaps.
Common is a virtual ground. 120V RMS AC can be ~ 240 on the up swing and be technically correct if neutral and down swing are proportionally offset1. Netural would still be way off of true ground. Extreme example, but shows how neutral is not a true ground.
mindfold
12-21-2015, 21:55
Neutral is for the transmission, ground is for safety. It is there so that you do not become the easiest path in the circuit.
Colorado Fatboy
12-22-2015, 23:43
According to the NEC, the white or neutral wire is the "grounded" wire and the green or bare wire is the "grounding" wire. They are not interchangeable.
Correct, they are two different wires for different purposes. The grounded or neutral conductor white wire is what completes your circuit and is a current carrying conductor. The grounding, equipment grounding conductor or "ground" green or bare wire is to carry the current to ground in the event of a ground fault. There should never be any current on this unless there is a problem.
To the OP what kind of wiring do you have? Is it a two wire cable (Romex)? Or single wires in conduit? Has your panel been upgraded or original? Do the white wires run to the ground block in attic you mentioned?
Going to updated panel. Old romex, but may be 3 wire. Looked around for grounding block and didn't see one. I'll post again when I can really get into the project.
Great-Kazoo
12-23-2015, 02:22
Going to updated panel. Old romex, but may be 3 wire. Looked around for grounding block and didn't see one. I'll post again when I can really get into the project.
Pictures would help.
Colorado Fatboy
12-23-2015, 15:55
Reading through this there are a few things that I would like to point out.
As soon as you start updating the wiring, including grounding, it has to be done up to code. This just means that the wire insulation type and conductor sizes are correct per the breaker sizing. The codes exist for a reason, so it is not a bad idea depending on how your wired, and what condition the wiring is in.
Per the NEC you can run the ground separate from the live and neutral, but I think that this is mostly for grounding of equipment where you have a neutral bonding jumper. That is the only time that I see this done as a commercial inspector. So you might be able to do it and cite the code, but the real best method would be to replace wire with correct new wire. Also keep in mind that per code you need to secure all conductors within three feet of the box, so you will need to get behind the drywall anyway to tack the ground to the stud.
Also if you are replacing your main panel it will require a permit and inspection from the city. There are a lot of things that need to be done to make the job safe. You might look at getting a quote from a licensed electrician. Take that quote look through what they recommend, and see if it is something that you can do yourself. It will give you a better idea of what would be needed and you can ask a bunch of questions to the electrician. Get a good company in there and they will tell you the best way to do it.
Yes, the NEC says you can run a separate grounding conductor, NEC 2014 250.130(C) HOWEVER you are not allowed to run regular (THHN) wire unless it's in a raceway (protected) So it makes no sense at all in this type of setting. You're much better off putting in new Romex to update the system entirely. You are confused on the support requirements. Within 36" of the box refers to conduit not cables, they are usually 12" from box under most circumstances, HOWEVER if you are "fishing" into finished walls the code allows you to put it in without support. NEC 2014 334.30 (B) (1)
Just wanted to clarify this so nobody gets the wrong information. I think calling a licensed electrician for a quote is a great idea, in fact get a few quotes.
gnihcraes
12-23-2015, 16:27
get the panel upgraded. (pull a permit, we didn't once and got screwed by a licensed electrician - fail on his part to do it right)
Put some nice large junction boxes in the attic/basement where accessible.
Start running new romex to each outlet either from attic down or basement up, wherever the old stuff was. Use the old as a pull cable for the new stuff.
We did this on my house, and every weekend or so, run another new romex. Takes time, but the house is all new now wiring. Trying to fix up the grounds was as much work as just running new stuff.
Doubt I need a new panel. A room was built onto the back of the house years ago so the panel is pretty new and has plenty of space. My original plan was just to run new romex to each outlet and try and do a different room each weekend, exactly as suggested.
Powered by vBulletin® Version 4.2.3 Copyright © 2026 vBulletin Solutions, Inc. All rights reserved.