250.104(B) Other Metal Piping 2014 NEC

[Smart $]

Such as "whose probability of becoming energized during any one year period is greater than .10"?
And requiring a PE for every such calculation?

Even more so concrete and definitive....

 

[Dennis Alwon]

Again , my feeling is that the gas pipe is more likely to be energized if there isn't a branch circuit feeding the gas equipment. Heck at least there is an equipment grounding conductor when the unit has power

 

[GoldDigger]

Again , my feeling is that the gas pipe is more likely to be energized if there isn't a branch circuit feeding the gas equipment. Heck at least there is an equipment grounding conductor when the unit has power

There is a counter argument to that.
It does not say how long it has to stay energized, nor at what voltage. So even with the EGC present the pipe could become energized, briefly.

 

[Dennis Alwon]

There is a counter argument to that.
It does not say how long it has to stay energized, nor at what voltage. So even with the EGC present the pipe could become energized, briefly.

That is an argument only found from someone who is looking for an argument.

 

[RB1]

I agree that piping systems do not have sharp corners, but rodents have sharp teeth. I can't tell you how many attics I have been in where the sheathing and insulation of NM cable have been eaten by mice or squirrels. If the NM is kept off the pipes, I agree that it is not likely to be energized. Where NM is installed in direct contact with conductive material, it is my view that the conductive material should be bonded.

 

[don_resqcapt19]

FWIW, "likely to happen today" is vastly different from "likely to happen once during the 40 year expected life of the equipment." We design for the later case.

I don't think it is likely to happen over a 40 year life either.

 

[don_resqcapt19]

Again , my feeling is that the gas pipe is more likely to be energized if there isn't a branch circuit feeding the gas equipment. Heck at least there is an equipment grounding conductor when the unit has power

I don't think a gas pipe or a water pipe or the structural steel are "likely to become energized". Sure it is possible, but it is very unlikely.

 

[Dennis Alwon]

I don't think a gas pipe or a water pipe or the structural steel are "likely to become energized". Sure it is possible, but it is very unlikely.

I don't either but I am thinking it is more likely to be energized if there is no equipment grounding conductor then if there is an equipment grounding conductor. I don't think the odds in either case are very high, rather barely existing.

 

[don_resqcapt19]

I don't either but I am thinking it is more likely to be energized if there is no equipment grounding conductor then if there is an equipment grounding conductor. I don't think the odds in either case are very high, rather barely existing.

My point is that since it is unlikely that these things will become energized, you don't have to bond them.

 

[Dennis Alwon]

My point is that since it is unlikely that these things will become energized, you don't have to bond them.

Unfortunately with wording such as "likely to be energized" it is very subjective and an inspector probably will require bonding.

 

[ActionDave]

I always figured the only thing in a building "likely to become energized" is the actual circuit conductors.

 

[George Stolz]

I'll send you some help Dave.

 

[ActionDave]

I'll send you some help Dave.

As long as it does not involve me becoming likely to become energized I'll take it.

 

[iwire]

Reading between the lines as Smart stated it looks like they are saying that likely to be energized happens when a branch circuit feeds a gas appliance.

That was already the case in previous code cycles.

 

[Dennis Alwon]

That was already the case in previous code cycles.

In previous codes it was left more wide open, imo, to include other scenarios such as nm laying on top of pipe etc. By the statement in the 2014 I see it as basically defining that likely to be energized is only on circuits that feed gas pipes.

 

[iwire]

In previous codes it was left more wide open, imo, to include other scenarios such as nm laying on top of pipe etc. By the statement in the 2014 I see it as basically defining that likely to be energized is only on circuits that feed gas pipes.

From 2011

The equipment grounding conductor for the circuit that is likely
to energize the piping shall be permitted to serve as the
bonding means.

Do you think they mean you can break into a random NM laying on top of the pipe and use that EGC to bond that pipe?

I always took that sentence to mean via the equipment a circuit feeds.

 

[Dennis Alwon]

From 2011



Do you think they mean you can break into a random NM laying on top of the pipe and use that EGC to bond that pipe?

I always took that sentence to mean via the equipment a circuit feeds.

That can mean the circuit that energizes the gas equip. can use the equipment grounding conductor, it doesn't, IMO, say it as well as the 2014 that if no equipment is wired then no need to bond the gas. Yes I am reading between the lines just as we do in the 2011 but it seems a bit clearer

 

[Dennis Alwon]

Actually on reading the 2014 it is assuming we mean the circuit that feeds the appliance however, IMO if an inspector see a 6/3nm running across the gas line he could insist that the gas be bonded by the size of that equipment grounding conductor. No where does it state that the circuit feeding the gas appliance is the circuit to use. Boy that kills this thread...:lol: Imo.

(B) Other Metal Piping. If installed in, or attached to, a building or structure, a metal piping system(s), including gas piping, that is likely to become energized shall be bonded to any of the following:
(1) Equipment grounding conductor for the circuit that is likely to energize the piping system

 

[Dennis Alwon]

From 2011



Do you think they mean you can break into a random NM laying on top of the pipe and use that EGC to bond that pipe?

I always took that sentence to mean via the equipment a circuit feeds.

I agree with you but I don't think iot says what we think it says--charlie's rule... I think that is the intent especially after talking with other cmp members.. but

 

[iwire]

I agree with you but I don't think iot says what we think it says--charlie's rule...

Well using Charlies rules nothing has been defined for 2014.

Imagine that, the NEC leaving us with a cliff hanger with no black and white conclusion. hmy:





They are always setting us up for a sequel in three years.