JWelectric
Electrical Contractor/Instructor
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What is happening when you read 250.104(A)(1) is you are reading into it what you want it to say instead of reading it for what it says. 250.104(A)(1) is addressing metal water pipes only.I just re-read NEC 250.10x in its entirety. All metallic piping/conduits/raceways must be bonded, unless "unlikely" to become energized. In my limited experience "likely" always wins over "unlikely". I do not yet see bonding being "forbidden" anywhere in the code nor JW's quotes.
“Expansion fittings and telescoping sections of metal raceways†how does this apply to metal water pipes. If we are going to discuss metal water pipes let’s please stay on subject and not try to inject conduit into the pictureAs for bonding jumpers ... hmm. 250.98 and 250.98 mention "electrically continuous"
and 250.96.98 and 250.64E mention jumpers. 250.64E mentions "at both ends" of a raceway..64(E) is addressing the grounding electrode conductor installed in a metal raceway again not addressing a metal water pipe.
In some cases such as the metal raceway used with a non-metallic box bonding is required but at a water heater there is no requirement to install a bonding jumper nor is there a requirement to make and keep metal water pipes electrically continuous. Many years ago it was a requirement that all metal pipes be made electrically continuous but the Code Making Panel realized that the NEC had no power to the installation of piping systems therefore the requirement was removed.So far, I see nothing about bonding jumpers with respect to water piping (like I said, I believe it is tradition, except in Maine). JW, are you saying jumpers are OK for say maintaining a continuous EGC when using EMT around a plastic box, but not OK for making supply plumbing electrically continuous for bonding (safety)? If so, I could not out argue that using the NEC...
YES! Should for any reason your little heart wants to come up with for bonding the two together then the bonding jumper you install MUST land at one of the four places outlined in 250.104(A)(1). I would also be looking to see if the service was 150 amps or smaller being you used a #6On my latest remodel, I ran a #6 from the panel ground to the gas water heater cold inlet continuing on to the hot side without splice. This is in addition to the required grounding electrodes. JW, would you veto that?
Again this is selective reading instead of reading what is printed. Look closely to the first few words of that section, “Where installed in or attached to a building or structure, a metal piping system(s), including gas piping,†I think that gas is included and not the only thing being talked about in 250.104(B).250.104B covers the case of bonding the gas piping to the EGC of the gas furnace circuit.
250.104(A)(1) is addressing any pipe that has water in it and is already electrically continuous throughout its entire system, the reason why in the proposal the CMP used the word COMPLETE and 250.104(B) address the installation of metal piping systems that are not complete including gas.
And an electrical water heater can be replaced with a gas without an electrical permit. A busted pipe can be repaired without an electrical permit and the plumbing code will allow a metal pipe to be repaired with a non-metallic pipe and just what happened to all that worthless bonding when this happens.A gas water heater and/or plumbing fixture can be replaced without an electrical permit. Removing a hot to cold bonding jumper would be outside the scope of work, and thus illegal...
No my friend I do not keep up with the news in Seattle but I do watch the local news in Asheboro North Carolina including the weather. The requirement for bonding gas pipes is to remove and electrical current imposed upon it due to lightning and surges.Remember the houses that burned in Seattle a while back due to a utility ground fault? Why would anyone want a low impedance connection from an underground gas pipe to the utility neutral...?
It might also help if we understand just what is meant by “likely to become energized†used in Article 250 of the NEC. What will cause something likely to become energized? The simple answer is it will have an electrical appliance attached to it just like metal conduit is likely to become energized due to the conductors inside the raceway.
Is a NM cable installed somewhere in the area of the metal pipe likely to energize it? No more than it is likely to set the wooden framing member that it is stapled to on fire.
My gas logs are supplied by a 250 gallon tank 300 feet away from the house and are supplied by a ½ inch copper tube. There is no electricity connected to the gas logs and no CSST gas piping used and guess what, no bond is installed either.
I also have two water heaters that have non-metallic flexible connectors and the copper pipes in the basement are not bonded. Everything in my home is code compliant and very safe.
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