Correct way to ground receptacles

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gsahlot
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Correct way to ground receptacles

Post by gsahlot » Wed Jun 27, 2018 12:03 am

Hi Guys,

So in old houses from 60s which are not grounded, after upgrading the electrical panel to have a grounding bar, what is the correct way per code to ground the receptacles?

1. Can one just run a ground wire (something like this: https://www.amazon.com/WRGND100-Copper- ... nding+wire) from the panel to the receptacle?

2. Does the ground wire need to follow the same path as the existing cable carrying the conductors? Or can it follow whatever path is convenient?

3. Can the grounding wire be shared between circuits?

4. Finally if grounding wire is being run in attic, does one need to drill holes in joists and then run the wire through the holes or can the wire be just laid on top of joists without drilling any holes? What is the correct way per code? And in general, why do people drill holes in joists in attic to run wires through them in attic anyway, why not just run the wire without holes, what is the problem without drilling the holes?

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emtnut
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Re: Correct way to ground receptacles

Post by emtnut » Wed Jun 27, 2018 8:39 am

gsahlot wrote:
Wed Jun 27, 2018 12:03 am
Hi Guys,

So in old houses from 60s which are not grounded, after upgrading the electrical panel to have a grounding bar, what is the correct way per code to ground the receptacles?

1. Can one just run a ground wire (something like this: https://www.amazon.com/WRGND100-Copper- ... nding+wire) from the panel to the receptacle?
Yes you can. It's rarely done thou, because if you do the work to run the wire, an electrician would just install new cable.
gsahlot wrote:
Wed Jun 27, 2018 12:03 am
2. Does the ground wire need to follow the same path as the existing cable carrying the conductors? Or can it follow whatever path is convenient?
It can be a separate run (it still needs to be protected as any other cable however)
gsahlot wrote:
Wed Jun 27, 2018 12:03 am
3. Can the grounding wire be shared between circuits?
Yep
gsahlot wrote:
Wed Jun 27, 2018 12:03 am
4. Finally if grounding wire is being run in attic, does one need to drill holes in joists and then run the wire through the holes or can the wire be just laid on top of joists without drilling any holes? What is the correct way per code? And in general, why do people drill holes in joists in attic to run wires through them in attic anyway, why not just run the wire without holes, what is the problem without drilling the holes?
If the cable is run where there is less than 1 meter of headroom, then it need not be protected.

Although most attics are rarely used for anything, there is always a safety issue with exposed wires.
You can avoid drilling if you install the wire/cable on a running board.

You can also install a GFCI, then you can safely install 3 prong receptacles without the ground wire.

Answers based on CEC, if your in the US, maybe Aaron will chime in.
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gsahlot
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Re: Correct way to ground receptacles

Post by gsahlot » Wed Jun 27, 2018 9:29 am

Thanks @emtnut. Yeah, I am looking for US rules.
Yes you can. It's rarely done thou, because if you do the work to run the wire, an electrician would just install new cable.
Yeah, I guess re-wiring is an option but that would require to replace the cable which might be running within the wall horizontally through the studs and would require to open the wall and patch back, match the texture, match the paint etc., so I guess that would be much more expensive and more work than running single insulated wire. For example in case of single insulated wire, one can just the wire horizontally only in attic and come down vertically right on top receptacle avoiding opening walls anywhere, right? It would require little more extra wire though as wire would be going up and down through the wall but would this be an OK approach?
It can be a separate run (it still needs to be protected as any other cable however)
... If the cable is run where there is less than 1 meter of headroom, then it need not be protected.
When you say protected, you mean the wire should be in a cable or do you mean, wire should run through drilled holes in the ceiling joists?
Although most attics are rarely used for anything, there is always a safety issue with exposed wires.
The green wire like this https://www.amazon.com/WRGND100-Copper- ... ouse008-20, I think is an insulated one (not exposed), so there shouldn't be any safety issue there, right? Or is that bare copper grounding wire (something like this: https://www.homedepot.com/p/Southwire-8 ... /202316516) the preferred option?
You can avoid drilling if you install the wire/cable on a running board.
Did you mean run the wire/cable along the edge of the joist or did you mean to install some extra board? Could you please elaborate more?
Answers based on CEC, if your in the US, maybe Aaron will chime in.
Will wait for Aaron's answers too. Thanks much!

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Aaron
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Re: Correct way to ground receptacles

Post by Aaron » Wed Jun 27, 2018 10:08 am

gsahlot wrote:
Wed Jun 27, 2018 9:29 am
Thanks @emtnut. Yeah, I am looking for US rules.
Hullo.
gsahlot wrote:
Wed Jun 27, 2018 9:29 am
Yeah, I guess re-wiring is an option but that would require to replace the cable which might be running within the wall horizontally through the studs and would require to open the wall and patch back, match the texture, match the paint etc., so I guess that would be much more expensive and more work than running single insulated wire.
It would be. But then running individual conductors to multiple receptacles is a pain too. But probably less of a pain than figuring out the path of wires you can't see behind walls.

What type of electrical cabling is preexisting in the house? Is it old 2-wire NM cable (non-grounded), or is it flexible metallic conduit (also known as "greenfield")? It looks like tightly coiled steel hose, usually about 3/4" in outside diameter. Very common in 1960s construction.
gsahlot wrote:
Wed Jun 27, 2018 9:29 am
For example in case of single insulated wire, one can just the wire horizontally only in attic and come down vertically right on top receptacle avoiding opening walls anywhere, right? It would require little more extra wire though as wire would be going up and down through the wall but would this be an OK approach?
It would. I'd feel a little squeamish about running the conductor itself behind the walls, as it's really rated and designed for operating within conduit. But since it's not current-carrying and is a ground, there's no electrical danger with it exposed. You could run bare uninsulated copper, for that matter.
gsahlot wrote:
Wed Jun 27, 2018 9:29 am
It can be a separate run (it still needs to be protected as any other cable however)
... If the cable is run where there is less than 1 meter of headroom, then it need not be protected.
When you say protected, you mean the wire should be in a cable or do you mean, wire should run through drilled holes in the ceiling joists?
Hmm, not sure what he meant by that, it could be a provision in Canadian Electric Code code (CEC). As for the NEC in the US, I'd protect it to the same extent as protecting NM cable. So it should within conduit (FMC or EMT) along the surface of a wall if it's not behind a wall, protective nail plates over drilled holes in joists or studs where the hole is less than 1 1/4", etc. You could string it through existing holes in joists with NM already going through, etc.
gsahlot wrote:
Wed Jun 27, 2018 9:29 am
You can avoid drilling if you install the wire/cable on a running board.
Did you mean run the wire/cable along the edge of the joist or did you mean to install some extra board? Could you please elaborate more?
I think he means that the board would be a surface by which to staple cable too. I personally would run it through studs or joists, however, with the 1 1/4" margin from the edge of the structure to the hole where you run the wire.

Honestly Wayne's idea of using a GFCI is really a good one. It's sort of a quasi-ground. The way it works is the GFCI will sense if there is current on the ground pin of a plug and will immediately trip its breaker if there is. So it offers a lot of the safety that a real ground offers, arguably more so with its other features. It's a common retrofit in homes with just two-wire circuits.

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Re: Correct way to ground receptacles

Post by gsahlot » Wed Jun 27, 2018 11:32 am

Thanks Aaron!
What type of electrical cabling is preexisting in the house? Is it old 2-wire NM cable (non-grounded), or is it flexible metallic conduit (also known as "greenfield")? It looks like tightly coiled steel hose, usually about 3/4" in outside diameter. Very common in 1960s construction.
It is mostly old 2-wire NM cable but in some places it is 3-wire and those receptacles (for example the ones in kitchen, bathrooms) are grounded, not sure where does that ground wire go through.

Somehow I don't feel that great about having GFCI with a sticker saying not grounded. Sticker kind of shows shortcoming in the outlet, want to fix that.

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Re: Correct way to ground receptacles

Post by gsahlot » Wed Jun 27, 2018 12:06 pm

It would. I'd feel a little squeamish about running the conductor itself behind the walls, as it's really rated and designed for operating within conduit.
But the wire I am thinking to use is https://www.amazon.com/WRGND100-Copper- ... ouse008-20 which has insulation, so it should be safe no? Or even the insulated wires should be inside the cable?

Also, is 10 gauge size the right one? Or should I use some other size? This will be used for receptacles in bedrooms and living room.

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Re: Correct way to ground receptacles

Post by Aaron » Wed Jun 27, 2018 12:29 pm

gsahlot wrote:
Wed Jun 27, 2018 11:32 am
But the wire I am thinking to use is https://www.amazon.com/WRGND100-Copper- ... ouse008-20 which has insulation, so it should be safe no? Or even the insulated wires should be inside the cable?
Sure. Insulation or not, it's good. I would at least match the gauge of the conductors connected to the terminal screws of the receptacles. If you have 15 amp circuits, that's usually 14 gauge. But you could use 10 or 12 if you want to.

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Re: Correct way to ground receptacles

Post by gsahlot » Wed Jun 27, 2018 7:49 pm

Sounds good. BTW, is there any limitation on the run of the single wire? For this wire I listed on Amazon i.e. https://www.amazon.com/WRGND100-Copper- ... nding+wire I read in reviews people saying it cannot be run for more than 20 feet. Is that really true? I would be needing it to run for much more than even 50 feet.

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Re: Correct way to ground receptacles

Post by Aaron » Wed Jun 27, 2018 10:11 pm

No. That's fake news. lol

You can run it as long as need be.

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emtnut
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Re: Correct way to ground receptacles

Post by emtnut » Thu Jun 28, 2018 8:40 am

When I said protected, that means that for the run of wire, it needs to be either inside a wall or run through the joists (just like if you were running romex)

For attics, you don't need to protect the wire (it can be run just under the insulation) if there is less than 1 meter of headroom (ie, near the edges of the attic)

If you have more than 1 meter, then you can install a running board (strapping/furring) and attach the wire to that (same idea as in an unfinished basement)
Although it is code to protect the wire in an attic, I've rarely seen it done .... inspector never goes up there to look :lol:

#10 wire is really overkill. I'd just use a roll of #12 solid, much cheaper too.

The 20' limitation is for communications bonding to ground, doesn't apply here as Aaron mentioned.
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Re: Correct way to ground receptacles

Post by gsahlot » Thu Jun 28, 2018 10:18 am

Thanks guys. That helps a lot.
#10 wire is really overkill. I'd just use a roll of #12 solid, much cheaper too.
I am planning to have three separate runs of this ground wire each on one side starting from a point in panel and on other side going inside the house daisy-chained through 7 outlets. I can see that the circuits on which outlets (to be grounded) are sitting, are all 20amps (well, I think they are 20amps because the breakers in panel have 20 printed on it. I maybe wrong I guess). I don't understand the sizes enough so unfortunately, I cannot tell the gauge of wire just by opening the outlet and look at the stripped wire. :-(

So I was just trying to be on safer size by using #10 but yeah, don't want to waste money if that is really not needed. Do you think in the situation I described above #12 is perfectly fine? Also 7 outlets per run of the wire is OK or is 7 outlets too many and I should have more separate runs?

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Aaron
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Re: Correct way to ground receptacles

Post by Aaron » Thu Jun 28, 2018 11:50 am

The cable sheath might reveal some indication of the size of the conductors within it. Unless it's that old-style Romex that is all black without any markings on it.

If the circuit is 20 amps, it should have 12 gauge cabling.

Since it's a ground wire, you can string as many receptacles and switches on it as you want.

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Re: Correct way to ground receptacles

Post by gsahlot » Thu Jun 28, 2018 1:11 pm

If the circuit is 20 amps, it should have 12 gauge cabling.
I will investigate if I can see the gauge size on sheathing of the cable but looks like #12 should be good enough?

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Re: Correct way to ground receptacles

Post by Aaron » Thu Jun 28, 2018 1:31 pm

Otherwise the other way to tell is to use a pair of wire strippers. The copper should be sized rather precisely to the hole matching its corresponding gauge.

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Re: Correct way to ground receptacles

Post by gsahlot » Thu Jun 28, 2018 8:14 pm

Check it out, some places it is #12 and few #14. #14 is for those circuits which are 15 amps and #12 for those which are 20amps. This seems expected per the info from you guys, so I guess I can just use #12 for grounding.

BTW, for the outlets, which ones should I buy 15amps or 20amps? All these outlets are on 20amps circuits but there are multiple outlets on each circuit. Also, I want to replace old light switches by new decorative ones, should I buy 15amps or 20amps?

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Re: Correct way to ground receptacles

Post by Aaron » Fri Jun 29, 2018 12:22 am

Use 15 amp recepts on your 15 amp circuits with the 14 gauge wire.

For the 20 amp circuits, I think I remember it being code that the first receptacle closest to the panel needs to be rated 20 amp, and it's optional to use 20 amp ones beyond that first one (you could continue on with 15 amp ones).

For switches, you’re fine with ones rated for 15 amps. Assuming you’re switching normal household fixtures.

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Re: Correct way to ground receptacles

Post by emtnut » Fri Jun 29, 2018 6:49 am

You can put 15A recepts everywhere. On a 20A circuit, you only need a 20A receptacle if there is only the one device, and it is a simplex.


Just a note** It would be a good idea to take a couple of good pics before you replace anything. Clear pics of where the wire comes into the box, where each one goes, and both sides of each device.

You can run into a few problems with switched outlets, split circuits and if you are doing any switches there is 2 3 and 4 ways. It can be hard to figure out the wiring after the fact !
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Re: Correct way to ground receptacles

Post by Aaron » Fri Jun 29, 2018 7:26 am

Agreed - be sure to note any duplex receptacles with broken-off bridge tabs between the pairs of terminal screws. Those are usually switched or are powered by two different circuits.

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Re: Correct way to ground receptacles

Post by gsahlot » Fri Jun 29, 2018 11:17 pm

Thanks for the info on outlets and switches guys. Now that I have upgraded panel installed with proper grounding setup, I am thinking if I should revisit my grounding method. I see this thick heavy bare copper wire for grounding which goes from panel to grounding rod. This wire passes through my attic, so I am just thinking if I could just "use bare #12 gauge grounding wire (instead of insulated one)" and "run it from outlets to somehow this thick heavy wire instead of to the panel", after-all panel itself is also connected to this thick heavy wire. The only thing I am concerned is how would I join my #14 wire to this thick wire. Do you guys think it is a sensible approach? Any suggestions?

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Re: Correct way to ground receptacles

Post by Aaron » Sat Jun 30, 2018 10:09 am

Is your panel in the attic? Unless it is, it's unclear to me why its ground conductor destined for a ground rod would enter your attic.

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Re: Correct way to ground receptacles

Post by gsahlot » Sat Jun 30, 2018 7:36 pm

Is your panel in the attic? Unless it is, it's unclear to me why its ground conductor destined for a ground rod would enter your attic.
No, it is on the back surface of the house but what they have done is put the ground rod near the edge of the front of the garage and have run the ground conductor from panel to those rods in front through attic and to the front of garage. Is that a bad installation? If yes, that's too bad for me, as they have already installed the thing, would have to ask the contractor now to get it redone. :-(

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Re: Correct way to ground receptacles

Post by Aaron » Sat Jun 30, 2018 11:49 pm

gsahlot wrote:
Sat Jun 30, 2018 7:36 pm
No, it is on the back surface of the house but what they have done is put the ground rod near the edge of the front of the garage and have run the ground conductor from panel to those rods in front through attic and to the front of garage. Is that a bad installation? If yes, that's too bad for me, as they have already installed the thing, would have to ask the contractor now to get it redone. :-(
Did they explain why they had to do it that way? Why couldn't the rods have been right near where you panel (and I assume your meter) is?

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Re: Correct way to ground receptacles

Post by emtnut » Sun Jul 01, 2018 7:57 am

I agree with Aaron, definitely not the ideal set up, but not against code. Sometimes 'stuff' is in the way (patios, decks etc.)

Moot point. That wire is your Grounding Electrode Conductor. You can't tie in Equipment Grounding Conductors to it.

You can tie in at any other 'grounded' outlet, or bring them down to the panel.
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Re: Correct way to ground receptacles

Post by gsahlot » Tue Jul 03, 2018 10:19 pm

They said concrete around the building was coming in their way. They could drive the rod right next to the side fences but then will have to run the grounding wire along the surface of concrete which would be against the code. In any case, when the inspector comes in to check they will tell if it is not done correctly.

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