electrical wiring/hot water ground

[timO']

I am getting ready to pull an 220V/80A branch circuit to my new inside heat pump. I am upgrading my 100A service to 200A locating the new meter right next to the old one; and putting a new 200A load center, then two branches; one to the existing 100A breaker box and another branch circuit off the new 200A load center to the heat pump.

THE QUESTION IS: I was advised to run a solid copper ground to my hot water heater, but my water heater connects to everything with plastic pipe. I don't see the point of running the wire to it.

I will be grounding the new meter; new load center, and existing load centers to two existing ground electrodes right near the existing meter. Since I already bought the 50' of #4 solid for the water heater ground; I'll use that wire for this purpose comments?

[Kadaitcha Man]

timO' Thou odd worm. Thou wilful boy. Ye trivialised:

Dumbfuck.

Water in metal containment vessel + electricity = death.

Yeah... what f****ng country are you in, you slack-jawed moron? And what do your local standards say you must do, you f****ng great galah?

[RBM]

I would get clarification as to what the "adviser" was talking about. If it's an electric water heater, it needs an equipment ground. I think they may have meant use a #4 ground conductor to the "water meter", which is typical if you have metal piping feeding the meter

[Jeff Wisnia]

You don't see the point now, so let me make it clear enough for even you to understand.

I'll assume that your water heater is electric, though you seemed to feel that we'd all be able to define whether it's gas or electric just by closing our eyes and thinking about it.

If an electric heating element in you water heater corrodes through it can connect a potential of up to 120 vac with respect to ground into the water in the tank.

Unless your place is supplied with perfectly distilled water, the water will have some degree of electrical conductivity and thus carry that potential throughout the plumbing system.

Now picture what happens when some kid is standing barefoot on a wet lawn outside and somebody decides to squirt him with the garden hose, using water carrying 120 vac with respect to ground.

Capice?

If it's a gas fired water heater with its own ignition system not requiring a connection to a 120 volt source, the above argument isn't appropriate, but there may be other reasons for grounding it.

Jeff

[Rich]

Are you sure? cold water pipe and a driven ground rod. Is required under section 250 of the NEC National Electrical Code. your four wire cable going to your heat pump has a ground in it for the job.

[timO']

Well S'Cuse meee girls Why do I have to sift through all this filth to get one lgitimate reply?

i guess I omitted that the water heater is existing, and electric. it has its own fused disconnect adjacent to it, and the branch circuit wired to it had a ground to the load center. The well pump is similarly wired with a cutoff and a ground. I think my friend (a master electrician) who advised me to run a ground to the water heater was thinking I could get a clamp onto a cold water pipe going into the water heater, but there is no metal pipe in my system except small spans between the well tank and the filter, then a piece for the cutoff valve. Nothing going to ground; and as I am trying to say; it is not city water; it an underground pump which connects to the house with non-metallic 'hose'. It's a small old house in a rural area in the South. I bet it had cast iron pipes originally, and they had to replace it as it constricted. And they used the cheapest materials they could.

[John Grabowski]

Hi Tim. I'm glad to hear that you've been continuing to do your homework with planning out this job and will soon be doing it. I'm thinking that the advice that you received about grounding the water heater was for the installation of a bonding jumper. This is usually done at the water heater to bond the metal hot water, cold water, and gas pipes together. The code calls for all interior metal piping to be bonded together, but does not specify that it must be at the water heater. If your water pipes are non-metallic then there is no need for the bonding jumper.

With regards to the existing ground rods, they must be a minimum of 6' apart however 16' or more is optimum. Also you should know that copper plated ground rods have a rated life of 40 years. Non-copper are much less. So you might want to consider driving new ground rods if the existing ones are old.

[Jeff Wisnia]

What you just wrote reads like you're saying there is NO NEED to connect a ground conductor to an electric water heater.

Do you really mean that John?

Jeff

[RBM]

Neither John or the OP are referring to an "equipment ground" for the water heater. The way the OP phrased his questions, makes that hard to determine. They are referring to bonding interior metallic water piping to the service grounding system, which is often done at the water heater location

[HeyBub]

It might help to think as follows: The purpose of a "ground" connection to the water system is not to protect you from the electrical distribution network, it is to protect you from the water system. In other words, you are grounding the pipes, not the wires.

[John Gilmer]

Yep!

It's that simple.

[John Grabowski]

Jeff, the original poster's second post clarified that there already is an equipment ground to the electric water heater. I said it appears that he does not need the bonding jumper between pipes which I am presuming someone told him to do. These are two different things that do-it-yourselfers can get confused about.

Lighten up on the guy. He has posted here several times already seeking quality information before he starts the job. Too often I have seen people post questions after they have started the project without knowing all that they need to know.

[Jeff Wisnia]

Agreed, but his clarification was made about an hour after I'd posted my reply. (If I believe the times of day on newsgroup posts, which I freely confess sometimes confuse me.)

I said it appears that he

Agreed, I posted while I was waiting for my morning coffee to brew, and I really shouldn't communicate with any other living thing, including our cat Lard Ass, until I've had my first cup of java of the day.

Peace,

Jeff