What is NEC Code For This Grounding Scheme ?

[Doug Miller]

False. If metal water pipe is present, it is *required* to use it as a grounding electrode in addition to the other electrodes.

[w_tom]

An intelligent reply would have cited what you have problems with. But since you post insults, citing code numbers would not change your mind. Shame on RBM for not even knowing what can and cannot be conductors. Code is specific about what can be conductors. Pipes are no longer permitted. Those who are still living in 1970s would not know that pipes are not acceptable electrical conductors.

If spending more time reading, then your responses would be devoid of insults. Profanity identifies one who typically finds reading difficult - who do not know. It explains why RBM knows pipes are acceptable as conductors. Profanity does not change the fact. Water pipes are no longer approved for electrical conductors. RBM should know that if posting recommendations here. Instead he posts profanity

- will not even state which parts he has problems with. Note to self. Don't take RBM seriously. His intelligence is defined by his reasoning - insults rather than facts.

[w_tom]

Using water pipes as conductors is not acceptable. We bond both water pipes and gas pipes (some jurisdictions) for the same reason - to remove electricity from those pipes. A bond to the gas pipe would not be an earth ground since gas meters routinely have electric insulators. Some jurisdictions want the gas pipe bonded to breaker box safety ground; others do not. Consult the gas company for what they want.

As w_tom repeatedly notes, the reason for pulling a cable is because that cable is approved as a conductor. Pipe that was acceptable as a condutor more than 30 years ago is no longer approved as a conductor today.

[w_tom]

It metal water pipe is present, it is *required* to be bonded. Interior metal water pipes must be bonded if the underground pipe is plastic or metal. Makes no difference whether the water pipe does or does not also do earthing. 1) it still must be bonded. 2) the water pipe earth ground is considered so inferior that some other earth ground electrode must be installed.

We must remove electricity (electrical faults) from pipes by bonding pipes to breaker box safety grounds. Some jurisdictions also want gas pipe bonded. All water pipes must be bonded so that electricity is not flowing in those pipes. Bonding is essential to human safety. Some jurisdictions so worry about electricity in the plumbing as to require a dedciated bond to steel bathtubs. Are we earthing the bathtub? No. We are bonding it so that electric fault currents will trip a circuit breaker. That also has nothing to do with earthing.

When the water pipe is bonded 'less than 5 feet' from earth, then it also acts as an earth ground. But code says the building is still not properly earthed. The building is not earthed until some other earthing electrode is installed. Code still says that water pipe is an earthing electrode (paragraph one). Code also says that water pipe earthing electrode is not sufficient. Some other earthing (from paragraphs two through seven) must be installed so that the building is sufficiently earthed.

That cold water pipe must be bonded even if the water pipe makes no earthing connection. Why? We connect to pipes to remove electricity

- for human safety.

[pawlowsk002]

Folks:

"He who argues with a fool makes two"

For everybody's benefit but the silly goose's, the reason we must now supplement the water-pipe ground with a driven electrode is because the city might use plastic pipe or dielectric unions. An all-metal city water system, miles of metal pipe full of water buried in damp ground, is a very very very good ground, but we can't always depend on it staying that way.

G P

[gfretwell]

250.21 from the 2002 handbook

[Doug Miller]

Isn't that what I just said?

Restoring the part that you just snipped, you wrote: " If using any other earthing electrode, then a water pipe earthing electrode is not required. "

That's what I said is false. And it is. You got it right the second time around.

[RBM]

If the water pipe entrance to your house is metal, it must be part of the grounding electrode system. If it's plastic, obviously not. Any internal sections of piping likely to become energized, must be bonded to the grounding system. The code requires only one ground rod, however it requires you prove with a special meter, the quality of that rod. If you don't have one of these meters, you can just drive the second rod. In this NG there is a newer post about ground rods and Tom Horne pasted the Code section 250.50 which spells this out

[RBM]

Tell me you don't wear a tin foil hat

[w_tom]

Ahh, but that picture is not using pipes as a conductor. That 'less than five feet' is where the pipe is an earthing electrode according to code. Code defines a difference between an electrode and a conductor. To be an electrode, the connection to that pipe must be "less than 5 feet". If connecting the breaker box to earth via a cold water pipe anywhere inside the building, then those pipes are being used a conductors - not legal.

Some jurisdictions will reject your picture IF those ground connections are not together. Others may reject it altogether; want the ring ground (halo ground) or ground rod 6 AWG wire to be attached directly to the 6 AWG wire from breaker box with a split bolt or something that connects those wires together without the pipe.

All jurisdictions will reject that connection if the various grounds do not connect 5 feet from earth. If the pipe is being used as a conductor - if the pipe connected between those various clamps is many meters apart - then it is not legal. Since those wires bond adjacent to each other, then most jurisdictions will consider that pipe an electrode - not a conductor. From that picture: "Connection made within 5 ft of point of entrance of pipe." At that point, the pipe is considered an electrode - not a conductor.

Using pipes as a conductor to connect a ground rod to breaker box is not acceptable. In John Ross's situation, the breaker box was earthed to a pipe much more than 5 feet from where pipe contacts earth. Therefore the pipe (as an earthing connection) was being used as a conductor - no longer acceptable. That connection was sufficient for bonding pipes to the breaker box. But it is no longer acceptable as an earth ground. IOW from the perspective of code. John Ross had no earth ground until the electrician connected a ground rod to breaker box (again, a connection not made using his pipes).

For the pipe to be an electrode, code says that pipe connection must be less than five feet from earth. Electrode conductors can merge on one electrode. Connection to earth on pipes farther than 5 feet means the pipe is being used as a conductor. Yes, some jurisdictions may permit merging connections from various electrodes on one pipe too far from earth. Others may not if the pipe is not considered an electrode. But that picture clearly shows connection made adjacent where the pipe is a earthing electrode; is not a conductor.

[w_tom]

"If using any other earthing electrode" is not even a valid "IF" here. Replace "If using" with "Required is using" any other earthing electrode. Does not matter whether the water pipe is or is not an earthing electrode to breaker box. The error was that the state of the water pipe (if or if not an electrode) is completely irrelevant. The code now says some other earthing electrode from paragraphs two through seven MUST be installed. Yes exceptions exist. But those exceptions do not apply here. John had no earthing electrode. What John considered an earth ground was not connected 'less than 5 feet' from earth; therefore was not an earthing electrode. He must install one that meets current codes. That is what one electrician would have done if connecting a earth ground rod directly to breaker box - no other changes.

Relevant in John Ross's situation: John had no earthing electrode. His breaker box was earthed by using pipes as a conductor. John has no choice. His breaker box needs an earthing electrode that connects to breaker box via 6 AWG wire; not connected via pipes.

Connecting a ground rod to his pipe where pipe is an electrode still would not meet code. Both pipe and ground rod electrode would still be using pipes as a conductor. Not acceptable. He must connect a new earth ground rod to breaker box only via approved conductors such as 6 AWG bare copper wire.

[bud--]

Obviously high on drugs when he wrote this. And as Roy suspects, w_ protects himself with these:

I am an electrical engineer and master electrician f*ck head. What are your qualifications for pontificating on the electrical code? In this thread you are arguing against at least 2 electricians and an electrical inspector. Plus others. Plus a cast of thousands in your previous idiotic posts on this subject.

And it is you who regularly posts lies. Like in this thread.

[bud--]

Only for new installations. Adding ground wires for receptacles is not likely to trigger installation of a ?supplemental? electrode.

John has a water service pipe electrode.

What John has was code compliant when it was installed. There is no requirement to change the connection unless he changes the service.

Bullcrap. He also doesn?t have to bring his whole house up to the current electrical code.

Your stupidity is breathtaking.

[Doug Miller]

And now you've gone and gotten it wrong again. Metal water pipe is *required* to be used as a grounding electrode. You said it's not. That's not true.

[John Ross]

Even though I probably don't *have* to to it, I assume adding the ground rod would be a good idea since the added cost is minimal--I assume you agree? One thing on that aspect: this area generally has hardpan soil condition. Is that good or bad news?

But as far as these wire sizes everyone is throwing around: is that required or suggested? I hear this size 6 mentioned. Is that the code from the rod to the panel or is that just suggested. Also, does that change with the size of the service (this is 100 amp)? I think this latest electrician said something about size 10 or 8.

And, if it is bonded correctly to the first five feet of pipe, what size of wire is require for that (that would be around a 30 foot run)?

I never would have imagined trying to ground a receptacle would turn into such an ordeal! And, like I said, not one of these electricians know what I am talking about when I qquote the NEC codes you guys mention. Scary...Had I not asked in here, I would have gone with that one guy who had the isolated ground rod that made no sense now that it was explained to me here.

BTW, I thought I was clever and called the electrical supply places for a recommendation for an electrician. They were of no help. Can anyone think of another source that would know a good electrician?

-- John

[KLS]

They probably didn't want to risk the loss of future business from all possible electricians by appearing to endorse one over the others.

I get all my best contractor references from friends and colleagues; works every time. Ask around. Or tell us your location, and someone here might be able to recommend someone local to you.

[bud--]

Connecting ground rods minimum #6.

Services - depends on service conductors. Generally 100A #6 is minimum used (can be #8 but the requirements on installation are very restrictive).

200A service #4 #4 may be used instead of #6 because #6 also has some limitations on use without 'protection'.

It should be noted that comments are based on the National Electrical Code. The NEC has authority only as adopted by entities that have control over electrical installations - states, cities, ... The NEC is the basis for the local code everywhere I know of, but can (and is) modified by many jurisdictions. The inspector can also allow variances. In your case, the jurisdiction or inspector allows connecting the added receptacle ground wires anywhere on the water pipe while the NEC now allows that connection only to the first 5 ft of the water pipe. [If the wire from electric service to water pipe electrode is not in the first 5 ft, as was permitted in the past, it does not make sense to connect added ground wires in the first 5 ft. And the added ground wires can usually be more conveniently connected elsewhere in the electrode system.]

The NEC chapter on grounding is probably the most confusing of the commonly used chapters.

[gfretwell]

It is really based on the size of the service entrance cables 250.66, which is usually based on the service disconnect size but that varies between residential and commercial. Residential generally gets away with a smaller SE cable because of load diversity. The other rules refer to the particular electrode used. You never need more than a #6 to a ground rod/plate, #4 to a UFER. When you are stringing several electrodes togerther you need the minimum size for the best electrode down stream up to the 250.66 size. Water pipes always use the 250.66 size.

250.66 (short version) SE cable GEC size copper aluminum Cu Al Res service 2 or smaller 1/0 or smaller 8 6 typical 100a 1 or 1/0 2/0 or 3/0 6 4 typical 150a 2/0 or 3/0 4/0 or 250 4 2 typical 200a

[hallerb]

your better off using 2 ground rods because during wet weather one might pass the resistance check but not during a dry spell. in addition all grounds for things like telephone NID and satellite dishes must be joined together to meet code.

[w_tom]

Minimum that was required was an earth ground rod near breaker box and connected direct to breaker box. Your description implies no proper earthing existed. A ground rod connected as close as possible to the breaker box is the only upgrade required and serves other useful purposes beyond what is addressed by code. Other utilities (cable and telephone) should connect to that same ground so that those utilities provide minimally sufficient electronics protection (as hallerb suggests elsewhere). That suggested to meet current code even though other marginal earthing is not required to be upgraded.

I no longer rememeber if this recommendation was posted. Other simplest corrections to consider for human safety were summarized by volts500 in alt.home.repair entitled "Grounding Rod Info" on 12 July

2003 at recommendations are so simple, so easy, so inexpensive, and so improve human safety issues as to also be performed - to upgrade basic safety grounding closer to what current code requires.

The only thing you do not have (according to your description) and that you must correct is earthing of AC electric. Those additions to safety grounding inside the house (from volts500) and the tying of all incoming utilities to a common ground are required by current code; not necessary for you to upgrade; but should be performed anyway because those little improvements provide significant human safety improvements for so little effort.

What size should a ground wire be? That varies based on things such as the amperage of electric service as summarized by gfretwell. Standard used in most all homes is 6 AWG. Ground wire is usually larger than what is required by code. 6 AWG copper is an industry default standard for residential electric.