Grounding wire from panel to gas pipe???

[Bud--]

Assume underground metal water service pipe (10ft...) and a ground rod.

Your original statement was:

The underground water service pipe is REQUIRED by the 250.50 to be included as a grounding electrode. It has been thus fire was invented. Bonding requirements under 250.104-A (not 250.80) have been already met under the more stringent 250.50. The code clearly requires the water service pipe to be a grounding electrode. The water pipe clearly provides ?A GROUND FOR THE ELECTRICAL SYSTEM.?

If 250.104 was removed, the connection would still have to be made. If the water service pipe was plastic 250.104 would prevail.

Both Brad and AZNomad said the water pipe was a grounding electode. So far no one agrees with you.

You said: > The ground rod is the *primary* grounding > electrode, and the water piping is the supplemental electrode.

250.53-D-2. requires a "supplemental" electrode - your ground rod. The water pipe is clearly superior based on the size of grounding electrode conductor required for each electrode and by typical earth resistances.

You said: > You're also wrong about the reason The NFPA Handbook said the rod was there because the water pipe might be replaced in the future with plastic with the rod as a "supplementary" fall-back.

I'm not sure why you're having so much trouble grasping this.

bud--

[Doug Miller]

Yep. And that's correct.

The water pipe -- by itself -- is not permitted by Code to be used to ground the electrical system, and hasn't been for many years.

It's bonded to the *other* grounding electrode(s) to ensure that the water piping is always at zero potential with respect to the electrical ground.

Not sure why you're having such a hard time grasping that concept...

[Bud--]

2005 NEC 250.50 "All grounding electrodes as described in 250.52(A)(1) through (A)(6) shall be bonded together to to form the grounding electrode system." 250.52(A)(1) "Metal Underground Water Pipe. A metal underground water pipe indirect contact with the earth for 3.0 m (10 ft) or more...." 100(1) [definitions] "Grounding Electrode. A device that establishes an electrical connection to the earth."

If you are having trouble intrepreting: All grounding electrodes including Metal Underground Water Pipe shall be bonded together to to form the grounding electrode system that establishes an electrical connection to the earth.

What do you think it means?

Can you read?

bud--

[Doug Miller]

You're the one who has trouble reading, not me. I never said that metal water pipes shouldn't be part of the grounding electrode system -- I said that metal water pipes are not permitted to be the *only* grounding electrode, and that's a fact.

It's also a fact that the reason for bonding metal water pipes to the other grounding electrode(s) is to ensure that the plumbing cannot ever become live, no matter what might go wrong with the electrical system.

Sorry you're having such a hard time understanding.

[Randy]

More explaination...

EC&M

Beyond the 2005 NEC Changes: Art. 250 Grounding and Bonding By Steven Owen, National Code Seminars

link for article]

Code Quandaries By Mike Holt, NEC Consultant

[excerpt - see above link for full article] Changes to 250.50 were made to clarify that, where any of the following electrodes "are present" they must be bonded together to create the grounding electrode system.

Underground metal water pipe [250.52(A)(1)]

Metal frame of the building or structure [250.52(A)(2)]

Concrete-encased foundation or footer steel [250.52(A)(3)]

Ground ring [250.52(A)(4)]

Ground rod [250.52(A)(5)]

Grounding plate [250.52(A)(6)]

The intent of the change to 250.50 (wording changed from "if available" to "are present") and the addition of the exception was meant to require the use of concrete-encased foundation or footer steel as part of the building or structure grounding electrode system in new construction (if they are present), since they are considered "present" before they pour concrete.

Randy

[Bud--]

Your fact is not consistent with what you said: ?The electrical system has its own, *separate* grounding electrode. Metal water piping is bonded to the electrical system grounding electrodes to ensure that the metal water piping cannot become live,

*not* to provide a ground for the electrical system.?

I do not see how "*not* to provide a ground for the electrical system" can be read other than the water pipe is not to be a grounding electrode and the system grounding is provided by the system's "own, *separate* grounding electrode."

bud--

[Doug Miller]

It's real simple: the water pipe is bonded to the other grounding electrodes, not to provide a ground for the electrical system -- that's what the *other* electrodes are there for, remember? -- but to ensure that the metal water piping is always at the same potential as the electrical system's ground and therefore cannot become live no matter *what* might go wrong electrically.

I'm sorry that you're having such a hard time grasping this... but you really need to spend a little more time educating yourself before you post again.

[Bud--]

Particularly clear info on Ufer ground in new construction. Thanks

To me this wording is clearer than "concrete encased electrode", which to me implies that connection to the steel has been made available. Nothing else in the list is named as an "electrode".

IMHO the code should make this even more explicit. Good requirement though.

[Tom Horne, Electrician]

"250.50 Grounding Electrode System. If available on the premises at each building or structure served, each item in 250.52(A)(1) through (A)(6) shall be bonded together to form the grounding electrode system.

250.52 Grounding Electrodes. (A) Electrodes Permitted for Grounding. (1) Metal Underground Water Pipe. A metal underground water pipe in direct contact with the earth for 3.0 m (10 ft) or more (including any metal well casing effectively bonded to the pipe) and electrically continuous (or made electrically continuous by bonding around insulating joints or insulating pipe) to the points of connection of the grounding electrode conductor and the bonding conductors. Interior metal water piping located more than 1.52 m (5 ft) from the point of entrance to the building shall not be used as a part of the grounding electrode system or as a conductor to interconnect electrodes that are part of the grounding electrode system." Copyright 2002 National Fire Protection Association

Now who is it that needs to educate themselves?

[Doug Miller]

I hope you're not contending that metal underground water piping is permitted to be the *sole* grounding electrode...

Geez, *another* one with reading comprehension problems. I have never disputed that metal underground water piping is required to be part of the grounding electrode system.

The whole argument is over *why*.

[Thomas D. Horne, FF EMT]

Is your position on why so as to keep it at the same potential as the other electrodes? Yes or no no dodging.

My position on why is that it is the best electrode available on premises served by large underground metallic water systems. In a building with no internal metallic plumbing supplied by a utility that requires copper laterals; many do; why do we still need to connect the Grounding Electrode Conductor to that piping. How is it to become energized in the absence of interior metallic piping? Why does the code require that the portion of the GEC that is the connection to the underground metal water piping be sized according to the table rather than limited in size like the one to the Concrete Encased Electrode, Ground Ring, Driven Rods, and so forth. It is because it is a superior electrode to any of those others. How many Grounding Electrode Systems have you measured for impedance to ground? How many have you installed? I cannot answer such questions my self because I lost track decades ago. In areas served by metallic public water systems I've never found an electrode with a lower impedance to ground than the metallic water service lateral from the metal water mains. That includes the ground rings and genuine Ufers installed at radio stations and the deep driven rod arrays installed at telegraphic fire alarm receiving stations.

[Doug Miller]

I guess you haven't been following the thread too closely, because I've stated that quite explicitly a number of times -- even quoted a portion of the NEC Handbook that says exactly that.

[Bud--]

I think he is likely trolling.

or maybe he is a member of w_'s grounding cult.

bud--

[Tom Horne, Electrician]

Thanks Bud. I try to remember not to wrestle with pigs. You just get filthy dirty and the pig enjoys it.

[safecsst]

most of the discussion is on gas piping outside the house. It would be a g ood idea to electrically bond the internal gas piping - that is the piping that is downstream of the gas meter - to the electrical ground electrode. The reason being that if the gas piping is energized it can conduct electri city same as water pipe. Typically the gas appliance ground will suffice, but if there is an overvoltage from a transformer surge or lightning, the h igh impedance of the appliance ground wire doesn't provide a low impedence path to ground. For most CSST, the gas piping MUST be bonded to the electr ical ground. So to answer your question:

- Is it required by code? YES but the appliance ground is usually used as the bonding means, so that satisfies the code.

- Is it recommended? YES especially if you have CSST or flexible appliance connectors.

- Wire size? Most use a 6 gage bare grounding wire - stranded if its availa ble.

- Daisy Cha> When we had our electric service upgraded, the electrician (as

[gfretwell]

Interior piping is required to be bonded where likely to become energized and this normally happens via the EGC in the equipment served. Water pipe shall be bonded using table 250-66, the same as any other ground electrode. (ie: 4ga for a typical 200a service)

[John]

replying to blueman, John wrote: Dont you have to bond the gas line to the panel.

[trader_4]

Yes, metal gas piping inside a building is required to be bonded to the electric system ground.

[gfretwell]

The general consensus is it can be bonded using the EGC of the circuit likely to energize the gas pipe so that will typically be the furnace blower or electric igniter circuit in ranges, dryers or water heaters. As long as the hub in the valve where the pipe is connected in the appliance is grounded that usually meets the intent of the code.

[trader_4]

I found this, which agrees with that, unless it is CSST, in which case it needs to be bonded to the service electrode system.

Like many things, there is some interpretation. Like in the code where they say that any metal piping that could be energized or something to that effect. What does that mean? If it's a section of metal piping that's not connected to any appliance, it's partially exposed, does that qualify as yes, but if it's concealed and you can't easily touch it, then it's a no? I assume if it connects to any appliance, etc that is powered, then it's a yes.