Best/Correct Way to Ground A House

Factual Questions
1

I have an old house that has NO grounded outlets in it - they are all the 2-prong ones, and I want to install 3-prong GFI outlets in every outlet in the house. Yes, I know I could install them more centrally if I wished.

What is the best way to retrofit grounding to outlets? And how is it typically done in a new home? I understand that one can just ground to a water pipe, but that doesn’t seem to make any sense - every outlet in the house wouldn’t be running to a water pipe. It would seem that new houses have 3-conductor wires running to each outlet, and at some point (unknown) the whole thing is grounded to a water pipe.

But this also sounds problematic - given the way corrosion works, I would have expected a lot of homes to end up being “ungrounded” via corrosion breaking the contact on that single, central ground. So It seems like some other method may be used. A grounding rod/pole?

But anyhow - say I have a 2-story completely ungrounded house. Is there any easy way to ground it? And what is the “best” way to do so, assuming cost and effort is no object?

2

The GFI outlets should take care of your grounding concerns.

Here’s one usenet discussion as a cite.

http://groups.google.com/groups?hl=en&lr=&ie=UTF-8&threadm=3663%40ecicrl.ocunix.on.ca&rnum=6&prev=/groups%3Fq%3Dgfci%2Bground%26hl%3Den%26lr%3D%26ie%3DUTF-8%26selm%3D3663%40ecicrl.ocunix.on.ca%26rnum%3D6

3

The best way, if cost is no object, is to completely rewire the house. Pull new, 3-wire cable and install new sockets. You may have to (or want to) upgrade the service entrance and main breaker box at the same time.

3-wire sockets and GFI sockets are not the same. I don’t see why you want GFI-protected outlets in a non-ground floor except in the bathroom or kitchen, where codes require them. A standard 3-prong socket should do just fine most places.

If your house was originally wired, not with Romex, but metal conduit (flexible or rigid), there should be empty space inside the conduit. Then you can pull a third, green, ground wire from a central point and replace the sockets. This would be relatively cheap.

Grounding – it isn’t a good idea to run separate ground wires from each socket to a separate ground and it would be a lot of wires. This creates “ground loops” where there are slightly different electrical potentials between supposedly identical ground wires and current starts flowing where least expected. Standard practice is to gather all ground wires together (like a “tree” configuration) and connect to a metal water pipe at one central location.

4

In the house where I live (30+ years old) all sockets are three-hole outlets, in accordance with Swiss regulations. However, when I opened one of the outlets, I was very surprised to see that there were only two incoming conductors, the live and neutral. The neutral was connected to both the neutral and the ground connection points!
I don’t know if this is Swiss standard, but it seems a bit dodgy… It sure works, but it also made me a lot more interested in getting a ground fault breaker!

5

Anthracite, there are several different points you need to consider separately. I am assuming you are talking of a house in the US. Chances are the wiring is either 3 wire or two wire and metal shield even if the outlets are 2 prong. From the point of view of wiring there is probably little you need to do.

Having checked that, you can just change the outlets to whatever type you prefer. I installed GFCIs in bathroom and kitchen circuits (one GFCI can protect more outlets down the line) but I am not sure there is much point in installing them in other rooms. Yes, you can gain some protection but they can go off accidentally and it is a hassle to have them at floor level in difficult to reach places. Take your time to do the whole house as they are often a pain if the witres are old or short etc. I did my entire house over time.

Ok, so now you have the entire protective ground of the entire house at the main panel. Chances are your supply is grounded and you would best ground there.

Otherwise you can make a proper ground connection with ground rods. I would never use water pipes for grounding.

If you are going to do any electrical work you should buy the electrical code which is a small booklet you can buy in hardware stores. It will give you the basic rules and you will be sure what you are doing complies with the code.

6

IANAelectrician, but here’s my take:

Purely from a safety standpoint, GFCIs are an acceptable substitute for proper grounding as an open in a grounded neutral will trip a GFCI as soon as a path to ground is established. 1999 NEC allows the use of a grounding-type GFCI in an ungrounded box, just remember to put a “No Equipment Ground” sticker on the wall plate (smilies disabled and please see the last paragraph.)

For proper grounding for electronics, all grounds should be connected to the ground bus inside the main disconnect (probably the main fuse or breaker in your house.) Your grounds and neutrals should be conected to this point and should not be connected any further into your house (so as to avoid current flow through a ground.) This bus should be connected to ground. Your local authority may allow grounding to an outside water pipe as a primary ground, but my utility wants to see at least one electrode driven into the earth with the water pipes grounded as well. I agree with them for the reason you mentioned–you will get corrosion between the pipe and the clamp which could/will compromise the ground.

If you want to, you probably could snake ground wires through the walls of your house, but by then you have already fished wires everywhere and you could have run Romex and rewired your house for a little more effort. If this were my house, I would probably try to add one or two dedicated electronics circuits and run Romex to wherever I needed it.

Once again, IANAelectrician, but most of this should be ok as per National Electric Code for 1999 (the GFCI substitute for grounding certainly is.) I don’t think there were any changes to residential grounding with NEC 2002.

7

sailor, no offense, but I find the legalese of the NEC to be a hassle to deal with when I need a quick reference. I usually fall back on Richter and Schwann’s Wiring Simplified. It’s a good pocket-sized reference that covers most residential work pretty well (at the very least it’s not a Sunset Book.)

8

I have the National Electrical Code paperback booklet which I bought a few years back at a hardware store for under $5 but I cannot find it online.

If you go to www.amazon.com and search for “national electrical code residential” you will find a number of books for under $15 like [url=“http://www.amazon.com/exec/obidos/ASIN/0827334907/qid=1029422213/sr=1-5/ref=sr_1_5/104-9653974-8457546”]Electrical Wiring, Residential/Based on the 1993 National Electrical Code**. Reading something like that will give you a broad view of what you need to do.

At any rate, in summary you have three parts: The outlets themselves which you need to change. This is no big deal but very time consuming. You can do it over time.

The wiring. Chances are it already carries the grounding either by third wire or by steel shield. But if it does not, then you will have to rewire the entire house. All protective grounds need to be taken to the general distribution panel. (And never fused)

The grounding itself. My house wiring was grounded at the panel from the incoming supply (which I believe was grounded at the distribution transformer). You might want to consult this particular point with your power supply company or a local electrician who knows the local codes.

If you need to provide your own ground I would go with proper grounding rods and not with any pipes.

9

How old is the house? Is the existing wiring still in good shape?

To begin with, you need to check the building code in your locale. In San Bernardino Country, CA, for example, the safety ground (green) wire needs to be connected to two copper grounding rods driven to the ground “x” feet and separated from each other by at least 5 feet. Or at least that was the code when I built a house there.

Just out of high school I worked for my uncle wiring farm houses for the REA. Pulling wire through an old house is a pain in the a$$ but it can be done. You need a “snake” which is typically a length of, preferably flat, steel wire that you feed inside the walls. You feed the snake through, attach the Romex cable to end and pull the cable through. Occasionally you will run into a fire stop, or two-by-four crosswise between studs. Then you have to break out the wall to get through it. Exterior walls are probably insulated and it is difficult to pull wire through. You might have to remove the wall board or plaster in the stud bay where the wire is in order to do it.

If the code allows you could run a grounding wire along the top of the mop-board and then cover it with a molding like a quarter round.

All in all it’s going to be quite a project. An electrical contractor would be the sure-fire way, but I suspect he would advise that you not do it. There is an electrician who posts now and then. Maybe he will have some better thoughts.

10

Shoot! can a mod fix the coding please?

cornflakes, I was not suggesting she buy the full electrical code and become a licensed electrician. I have a booklet which cost me under $5 and has all the basics and some useful explanations. That is the type of thing I suggest,

11

The best way to ground a house is take away it’s television and send it to bed without dinner.

12

Anthracite, IANAE, but I did spend a summer or two working in an electrical supply distribution warehouse. The one point I wanted to add is that GFCI outlets are MUCH more expensive than standard residential outlets.

For example, a quick check on the Home Depot website suggests that standard residential outlets can be had for about $0.35, but GFCI outlets start at about $6.00. That’s a factor of almost 20 times more expensive.

A few outlets, no big deal. Replacing the whole house with GFCI - that could be quite an additional cost.

Noting disclaimer above, you asked for the Best/Correct way to ground a house, and I am quite sure that using water pipes IS NOT the best/correct way (marginal, perhaps).

Good luck.

13

Sorry sailor (what, me retentive?)

14

No contest. Look up “electric contractor” in the phone book. Pick one and call. Seriously. Make sure they’re licensed.

IANAE, but to expand on the comments above I believe that the NEC now requires grounding by a means other than the water pipe. I also believe that the code requires all ground wires to be routed to a single location, never separately grounded.

Here’s a point to consider: what if you sell your house in the future? Are you going to tell the buyers you did your own wiring? Are you going to not tell the buyers you did your own wiring? Would you want to buy a house where the owners did their own wiring, based on the advice of a bunch of anonymous people on some weirdo message board? (“Well, some guy named cornflakes told me this was how to do it…”)

Finally, what is your goal here? Do you really need three-prong outlets everywhere? Do you just need them in a couple select locations? Are the old outlets painted over, and you want new, clean ones?

(No offense, cornflakes)

15

I have rewired an entire house so I’ll jump in here. My house was 1920 construction with knob & tube wiring throughout. All my sockets were two-wire and there was no grounding. Being a geek, I wanted to make sure my numerous electronic devices were protected. The original plan was to rewire sockets in the computer room & the living room (for the stereo stuff). I ended up rewiring the entire house.

By all means, find out your local code requirements. In my town, however, there was no obligation to meet code on a retrofit - just on initial construction. I did, however, have to get a permit & have it inspected by the city inspector at various phases in the process. The city required that I have a licensed electrician handle the power-meter to circuit box replacement while I was permitted to take circuits from the box to the rest of the house.

Grounding to a water pipe is frequently forbidden these days. The water company employees got tired of being zapped by poorly wired houses. There’s also a lot of plastic pipe being fed into houses today so it can be a poor ground. Code for me required a single six-foot spike to be driven into the ground, this was wired to the circuit box and all ground circuits were tapped in there. (There’s a special wiring block in the circuit box for just this purpose). Grounding to electrical conduit is not necessarily a good thing - it may not be well grounded itself or may not be continuous all the way to the circuit box.

I ran 12 guage Romex (three-wire) throughout and sized the circuit breakers to match (important). If you have basement & attic access to all the rooms then it’s not too hard. If you have a two-floor house, then it’s much more trouble. If you have fire-plates in the walls, then there’s some sweating involved (get a long drill bit - like a cable installer’s bit).

Fixtures on the outer wall may be difficult if your walls are insulated (mine weren’t) and one trick that worked for me is remove the baseboards, run wire in a channel under them, and replace the baseboards. Mostly, though, the majority of new wiring ran along & through the ceiling and floor joists.

Make all wire junctions in junction boxes with appropriately sized wire nuts. Tape the wire nut to prevent it turning back off accidentally. Brace any ceiling fixture if it may have to support a ceiling fan one day - better now than later.

If you want GFCI protection throughout the house, it’s possible to buy a GFCI circuit breaker and protect the entire circuit. They’re expensive but probably not as expensive as a house where every socket is GFCI.

Rewiring was a major pain in the ass. I did, however, save a ton of money over hiring somebody.

Sunset publications, available at most big-box home stores, has a book on house wiring.

Tools:
[ul]
[li]Get youself a socket-tester for a couple of bucks (three prong plug with indicator lights) and a neon-bulb tester. [/li]
[li]Long extension cords are necessary to keep your power tools (and refridgerator) running as you work your way around the house. You can do most houses in sections. [/li]
[li]If you drill the floor/ceiling joists then get a big bit (splurge for the expensive one - the cheap blade-bits wear out fast), if the hole you’re pulling wire through is too small then dragging the wire through a series of them takes a lot of pull. [/li]
[li]Get a pair of electrician’s pliers - they’re gold. [/li]
[li]Consider cut-in boxes for new outlets - they’re designed to keep your walls intact. [/li]
[li]A light thin chain will “flow” through small holes to aid in “fishing” wires. Use chain and rope to pull the steel fish tape, use the fish tape to pull wires.[/li]
[li]Tape the romex to the fish tape as well as bending the romex over the end-hook. It seems wasteful to tape and untape the wire but the first time you catch the romex on some internal wall element and snap the hook off, you’ll realize the value of taping the joint.[/li]
[li]Overalls can turn you into a walking toolbox.[/li]
[li]Get the heavy-duty abusable light bulbs for your work lamp. Rewiring usually means working in the dark and having to grope your way around because you busted yet another bulb is not fun.[/li][/ul]

There’s tons more but I’ve already exceed the scope of the OP.

16

Granted that you don’t want to rely entirely on water-pipe grounding, and granted that you don’t want to rely on multiple separate grounds, is there any reason to not use both the pipes and a ground rod? That is to say, all ground wires are connected to each other, the network of ground wires is connected to the plumbing network in one or more places, and the network of ground wires is connected to copper bars driven into earth in one or more places.

17

**Chronos **, NFPA 70 250-104(a) (aka 1999 code) says:

My impression is that the idea is to ground the pipes, not to use the pipes as a ground.
(No offense taken, ZenBeam. That’s partly why I keep this username.)

18

It used to be that you HAD to ground your house via the water pipes. Then they changed the rules, and the one thing you can’t use to ground your house with is (you guessed it) the water pipe. But, you still have to ground the water pipes so that you are sure they have a good connection to electrical ground, otherwise an unsafe condition could result.