water heater

[LarryFine]

Does cold water create a shock hazard?

It does if the water is cold enough!

 

[mvannevel]

Does anybody else get the impression they are adding an undue amount of inflection to make this statement hold water? I feel like they're blowing smoke up our butts.

What is the bonding of metal water pipes for at all, if they're perfectly content to not bond half of them? Does cold water create a shock hazard?

I agree with you George. The wording in 250.104(A) tells us metal water piping systems shall be bonded. It makes no reference, as found in 250.104(B), to "that may become energized". So, to me, for them to use the language found in 250.104(B) for Other Metal Piping to turn down the proposals seems quite curious. You could very easily have a metal water piping system with a non-metallic fitting (a filter or the like) that would prevent the entire system from being bonded. And just as easily on the same system it would be possible that there is nothing of an electrical nature connected to this piping system (electric water heater, water softener, etc.) that would provide an equipment ground that would be used for this bond as they suggest. So are we to just leave this section of metal water piping unbonded?

Like gndrod, I interpret this section to mean the entire piping system is intended to be bonded. That's what 250.104(A)(1) tells us to do.

What I am looking for is something that would substantiate an inspector requiring a bonding jumper to be installed between the hot and cold water pipes.

There are some inspectors in this country that feel that this is a requirement when installing a bonding conductor as outlined by 250.104 but I just can?t find anything that will substantiate this in the code.
By what rule could this be enforced?

I think what this is Mike is a strict interpretation of 250.104(A)(1). If you have a cold water piping system and a hot water piping system, they both need to be bonded (if they aren't already tied together by the plumbing itself). I really don't think this is a case of the "mean 'ol inspector" trying to make the electrician do more work, but a case of "the book says metal water piping systems must be bonded, so bond it". I always jumpered around those things that interrupted the continuity of the piping when I was contracting without being told by the inspector.

I really agree with George here. If all of the piping doesn't have to be bonded, then why bond any of it?

 

[jwelectric]

I think what this is Mike is a strict interpretation of 250.104(A)(1). If you have a cold water piping system and a hot water piping system, they both need to be bonded (if they aren't already tied together by the plumbing itself).

Would not the hot and cold come from the same water system?
Is there truly two different systems or just one?

In proposal 5-235 Log #1834
The Substantiation:Nonmetallic water piping systems are being inserted between our metal water piping system and today?s code is not recognizing these changes.

Panel Statement:The conditions indicated in the substantiation are already covered by 250.104(B) where there is not a complete metallic water piping system.

Here the panel says that if the water piping system is not complete or a nonmetallic piece is installed then 250.104(B) would apply

In proposal 5-236 Log #2432
The submitter states; With much expanded use of plastic water piping system(s) isolating section of metal piping systems. This type of installation leaves contractors and inspectors what is required to be bonded.
And the panel replied; The requirements of 250.104(A) apply to complete metallic water piping systems. Where there is no complete metallic water piping system, then the requirements of 250.104(B) would apply for those portions of isolated metal water piping system likely to become energized.

Where are you getting that the panel is saying that they are to be bonded together? In both cases the panel referred to 250.104(B).

I really don't think this is a case of the "mean 'ol inspector" trying to make the electrician do more work, but a case of "the book says metal water piping systems must be bonded, so bond it". I always jumpered around those things that interrupted the continuity of the piping when I was contracting without being told by the inspector.

Neither do I think that this is a case of the inspector trying to be mean or ugly but I do believe that it is a simple case of not understanding what is being asked for by the code.

I really agree with George here. If all of the piping doesn't have to be bonded, then why bond any of it?

I can?t answer this question until my original question gets answered.
By what code section is the bonding around a water heater enforced when complying with 250.104?

 

[mvannevel]

Would not the hot and cold come from the same water system?
Is there truly two different systems or just one?


Neither do I think that this is a case of the inspector trying to be mean or ugly but I do believe that it is a simple case of not understanding what is being asked for by the code.

Mike-They may come from the same water system, but that doesn't necessarily mean they are the same metal piping system. And I guess that brings us to your last point, a lack of understanding of what is being asked for by the code. I think that is exactly what is happening here. I don't think this is the fault of the electrician or the inspector, but yet another case of poorly written (and maybe poorly substantiated) code.

250.104(A)(1) makes no mention of metal water piping systems that are likely to become energized. It only references metal water piping systems. 250.104(B) refers to other metal piping systems that may become energized. These two are clearly not the same thing.

 

[LarryFine]

Maybe someone need to check the plumber's version of the code and see if "electrically conductive" is part of the definition of a piping system.

 

[jwelectric]

Mike-They may come from the same water system, but that doesn't necessarily mean they are the same metal piping system.

Pray tell me what makes then different metal piping systems.

250.104(A)(1) makes no mention of metal water piping systems that are likely to become energized. It only references metal water piping systems. 250.104(B) refers to other metal piping systems that may become energized. These two are clearly not the same thing.

The same people that writes this section of the code are saying to use subsection (B) in the case of an insulating fitting being inserted in the system. Why are they saying this?

 

[mvannevel]

Mike-I see them as two separate systems from the standpoint of performing two different functions. One delivers cold water and one delivers hot. For the purpose of our discussion, that makes no difference as long as they are connected to one another to provide continuity for our bonding. However, if they are isolated from each other, we need to bond them together. At least that's my opinion.

The same people that writes this section of the code are saying to use subsection (B) in the case of an insulating fitting being inserted in the system. Why are they saying this?

That's a good question Mike. One I wish I knew the answer to. To me, referencing 250.104(B) in a situation where you have part of a piping system isolated from another makes absolutely no sense. How, in this case, do you determine the rating of the circuit that may energize the piping system?

Let's look at a specific application. A building is supplied by non-metallic water supply piping. Once inside the building, the piping changes to copper. There is a 30' section of this piping off of which branches supply outside faucets, an inside hose bib, and a slop sink. At the end of this 30' section of copper piping are 2 nonmetallic filter bodies. On the downstream side of these filters is another 30' section of copper piping with branches that supply a shower, lavatory, toilet, and gas water heater (no dielectric unions are installed on the water heater and the mixing valve bonds the hot and cold together). Okay, what and where do we bond here? Do we bond the first 30', the second 30', install a bonding jumper around the filter bodies, or bond nothing at all?

 

[George Stolz]

The same people that writes this section of the code are saying to use subsection (B) in the case of an insulating fitting being inserted in the system. Why are they saying this?

That's a good question Mike. One I wish I knew the answer to.

Ditto. Those panel statements make 250.53(D)(1) make even less sense than it did, which a feat.

 

[jwelectric]

I can understand why continuity would need to be maintained between the pipe and all points of bonding for the electrode system. I believe this is what George is thinking about with the words ” Continuity of the grounding path or the bonding connection to interior piping shall not rely….” found in 250.53(D)(1).

I connect a conductor from the panel to the first five feet of the water pipe and then connect all the other electrodes to this water pipe with “bonding jumpers”. I wouldn’t want to say hit the concrete rebar from the hot water pipe and the building steel from the building side of a filter or the ground rod from the building side of a water softener, that is if any of these were between the first five feet from the point of entry. I would want to make sure that all these “bonding jumpers” had continuity between them.

I have invested about fifteen minutes into doing some research on this bonding requirement found in 250.104 and this is what I have come up with.

Most of the time water lines are supplied to a building from underground unlike electrical utilities that will sometimes supply a building from overhead. This is totally beyond my comprehension why the water could not be supplied from overhead like the electrical. I suppose that plumbers just like to dig.

This big old ball that we live on, let’s call it earth has all kinds of stray voltages running around through out it in all kinds of directions and manners. I think this happened when the moon struck it sometime in the past couple of years or so or it might be all them lights that are burning around the North Pole are shorting out but at any rate we have a lot of stray voltages that no one will catch and send to the dog pound. Hey, we can’t even get anyone in my part of the country to get all the stray dogs let alone those stray voltages.

We all know that hydrogen nor oxygen (water) are good conductors of electricity but iron and other chemicals that are sometimes found in water are.
If we couple the fact that plumbers refuse to install the water supply to a building from over head and the fact that all these stray voltages are found running around unchecked in the earth I can understand why it would be important to bond the water supply to a building to some point on the electrical system after all we might get another short from them northern lights again. Who knows we might even get one of them flashes of light that happens when it thunders and we need to get all that light off the metal water pipes

To summarize all this and make it easy to understand.
When using the metal water pipe as an electrode continuity must be maintained between all points of the electrode system and the point of attachment of the electrode conductor with “bonding jumpers”. All this must take place with-in the first five feet of the metal water pipe. The grounding electrode conductor can also be used to bond the water pipe as mandated in 250.104 as long as any insulating point is bonded around between the point of the electrode (250.52) and the point of bonding (250.104).

When the metal water pipe is not being used as an electrode the bonding the metal water pipe will drain off any stray voltages strong enough to be conducted by the water such as imposed by lightning or any fault condition that may occur and the bonding around things such as filters and water heaters are not required and 250.104(B) takes over as outlined by the comments of the code panel.

I welcome any and all comments on this matter as I myself am trying to better understand how an inspector can require a conductor to be installed around a water heater when there is no requirement to do so to be found in 250.104 for bonding a metal water pipe.
The requirement to bond around such things as water meters or filtering devices and similar equipment found in 250.53(D)(1) addresses the metal water pipe as an electrode only and can not be applied to requirements found in 250.104. Where did this practice ever get started?

 

[mvannevel]

Just a couple of questions more than anything else Mike.

When the metal water pipe is not being used as an electrode the bonding the metal water pipe will drain off any stray voltages strong enough to be conducted by the water such as imposed by lightning or any fault condition that may occur and the bonding around things such as filters and water heaters are not required and 250.104(B) takes over as outlined by the comments of the code panel.

If that's the case (and I'm not saying it isn't), why bond around them when the underground portion of the pipe is used as a grounding electrode? After all, it should, in theory, work the same way you described above to drain off this stray voltage that may be conducted by the water whether you bond around them or not. And what if it's a completely nonmetallic water piping system from the outside into the house consisting of all plastic or pvc? The only metal here would be the submersible pump (which would maybe be covered under 250.104(B)?). Would we then be worried about stray voltage or lightning only on the water itself (providing there was a high enough TDS level to make it conductive)?

I welcome any and all comments on this matter as I myself am trying to better understand how an inspector can require a conductor to be installed around a water heater when there is no requirement to do so to be found in 250.104 for bonding a metal water pipe.

I'm trying to understand this better myself. I don't want to require something that the code doesn't. I may well be all wet when it comes to my understanding of bonding and the reasons we do so. These are all things taught to me by instructors, electricians, and inspectors as I was learning the trade. That doesn't automatically make them right, I know, and it's indeed possible that I was taught wrong. I'd like to look into this closer myself. Where did the information that you posted on the stray voltage aspect of this come from?

 

[jwelectric]

Before I address your post let me say that all this stray dog and voltage junk came from the top of my head. I was just trying to fill blank cyberspace.

If that's the case (and I'm not saying it isn't), why bond around them when the underground portion of the pipe is used as a grounding electrode?

Bonding around the meters, filters and such equipment found in 250.53(D)(1) is to ensure that from the point of attachment of the grounding electrode conductor and all bonding jumpers to other electrodes in the electrode system including the 10 feet of metal pipe in contact with the earth is continuous and not insulated from each other nor capable of being disconnected by the replacement or maintenance of these devices.
Should a bonding conductor be installed to fulfill the requirements of 250.104 and it landed anywhere on the metal piping system and all the conductors for the electrode system fall on the supply side of the entrance of the metal pipe then no bonding around these devices would be required.

A_______B_______C (from A to B is five feet, from B to C is 10,000 feet)

The metal water pipe enters the building at point A and all of the electrodes such as the rebar, building steel, ground rod ect land between point A and B with B being the filter, softener or other devices and then another bonding conductor is ran from the panel to point C there would be no need to bond around point B.

250.52(A)(1) is very clear that ONLY the first five feet of pipe that enters a building can be used as the electrode or as a point to bond any other part of the electrode system.
If a building had 10,000 feet of metal water pipe only the first five feet that enters the building can be used as the electrode or a point to attach other electrodes. The rest of the metal water pipe is required to be bonded as outlined in 250.104(A) and the only requirement found in 250.104(A) is that this point be accessible. No where does it require anything to be bonded around.

When I started this thread I was looking for someone to explain to me where the requirement to bond around a water heater that has dielectric fittings ever got started and a basis for this bonding. Where and how would the hot water pipe ever get energized with the dielectric fittings installed at the heater?
I have researched this back as far as the 1962 cycle of the NEC and can not find a requirement to bond around a water heater in any cycle.

I understand that this has been a practice of many for many years but I have not been able to find one person to back this requirement with a code section other than to say that the hot and cold are from two different systems. This is not true as I can direct the same water through either pipe I choose with a simple movement of the hand.

I have both 120 and 240 volt equipment in my home but both are supplied from the same electrical system just as all the water pipes in my home are supplied by the same system so in my opinion to say that I have a hot and cold water system would be a stretch at best.

Should I turn my water off then I can?t get water from either the hot or the cold. The same is true with my electrical. Should I turn off my electrical service I can get neither 120 nor 240 volts. How can I then have two different water systems?

Maybe this is what I do not understand, two different water systems. I can see two different systems when I am looking at a sprinkler and a fresh water supply but my mind just can?t grasp the idea that a water heater being supplied from the same pipe that supplies the cold water to a building constitutes a different system. It is the same water and is being used for the same purpose therefore the same system. What am I missing?

The other part that I seem to be missing is the desire to keep it electrically continuous. It is not being used as a conductor nor an electrode so why does it need to be continuous?

Again any help understanding this would be greatly appreciated.

 

[George Stolz]

I don't buy the stray voltage theory. You're bringing it into the structure. Now where is it going?

With a hot-cold seperation, then the cold could shock the user completing a path on the hot. Same problem, different path, same difference.

I don't have an answer.

 

[jwelectric]

I don't buy the stray voltage theory.

I don?t buy it either but I got in some good typing practice while typing it.

You're bringing it into the structure. Now where is it going?

I would think that we should hire a voltage control officer similar to the animal control officer to catch all the stray voltages and fine the owner if the stray voltages don?t have the proper voltage tags.

With a hot-cold seperation, then the cold could shock the user completing a path on the hot. Same problem, different path, same difference.

By What? Where will the current come from that will produce the shock? In 250.104(B) we are instructed to bond any pipe that in likely to become energized and are allowed to do this bonding with the equipment grounding conductor that is ran with the circuit conductors.

I don't have an answer.

I am seeking this answer and shall not stop until I find it.

 

[mvannevel]

By What? Where will the current come from that will produce the shock? In 250.104(B) we are instructed to bond any pipe that in likely to become energized and are allowed to do this bonding with the equipment grounding conductor that is ran with the circuit conductors.

That pretty well sums up my confusion Mike. 250.104(A)(1) makes no mention whatsoever about interior metal water piping "that may become energized" It merely instructs us to bond this piping. I see your argument that it doesn't say we have to bond every inch of this piping, but following that line of reasoning, it also doesn't say we only need to bond a few feet of it either. Or bond up to the first insulating joint. As I said earlier in this thread, the way I read it, I'm being instructed to bond all of the interior metal water piping system regardless of whether or not it may become energized.

The other part that I seem to be missing is the desire to keep it electrically continuous. It is not being used as a conductor nor an electrode so why does it need to be continuous?

I'm guessing for the same reason it needed to be bonded in the first place. If it makes sense for us to bond this metal piping system at all (even though it's not being used as a conductor or an electrode), then it also makes sense that the whole system should be bonded.

Here's where I see things having gone terribly astray. 250.4(A)(4) Bonding of Electrically Conductive Materials and Other Equipment talks about electrically conductive materials that are likely to become energized. 250.104(B) also mentions the phrase "that may become energized". However, this wording was not included in 250.104(A)(1). Why? It's been that way a long time, so I find it hard to reason that it was an accidental omission. Maybe (as I also mentioned earlier) this is either a case of poor code writing, or poor substantiation. I'm willing to believe that the intention is to have all of the metal water piping system bonded. Therefore, it's not necessary to mention the likelyhood of becoming energized or to bond around items that interrupt the continuity. Those are givens. I'm also willing to listen to anybody who can show me that this was never the intent of the code.

 

[George Stolz]

By What? Where will the current come from that will produce the shock? In 250.104(B) we are instructed to bond any pipe that in likely to become energized and are allowed to do this bonding with the equipment grounding conductor that is ran with the circuit conductors.

The hot could have contact to the earth through other means (by chance).

Stray voltage doesn't make the list for "likely to become energized."

I am seeking this answer and shall not stop until I find it.

I think the answer is, the panel has not thought this through entirely (as much as it pains me to say it).

They may have an opinion (perhaps even a consensus), but there is a vacuum where the words would be to clearly define the boundaries of the bonded world as they'd like to see it, IMO.

Perhaps they have not considered that not bonding half the system could possibly present a shock hazard, in the case of an open neutral or stray voltage. If cold happens to be bonded to the electrical system, and hot isn't, and hot has another earth contact of some kind, then there is a potential shock hazard.

I don't know.

 

[George Stolz]

One other chafing point I have: I submitted a proposal to change 250.104, and then another for 250.104(A)(1).

Either I somehow forgot to print it (because I'm looking at it right now on my computer, all ready to go) or they lost it. The answer to the proposal might have shed more light on this.

 

[jwelectric]

That pretty well sums up my confusion Mike. 250.104(A)(1) makes no mention whatsoever about interior metal water piping "that may become energized" It merely instructs us to bond this piping. I see your argument that it doesn't say we have to bond every inch of this piping, but following that line of reasoning, it also doesn't say we only need to bond a few feet of it either. Or bond up to the first insulating joint. As I said earlier in this thread, the way I read it, I'm being instructed to bond all of the interior metal water piping system regardless of whether or not it may become energized.

So to follow what you are saying, a system that has nonmetallic pipe but does have metallic stubs a bonding conductor sized by 250.66 would need to be installed at each stub and bonded back to the service. This would ensure that all metal pipes are bonded.

I'm guessing for the same reason it needed to be bonded in the first place. If it makes sense for us to bond this metal piping system at all (even though it's not being used as a conductor or an electrode), then it also makes sense that the whole system should be bonded.

What I am looking for is something concrete that will take all the guess work out of the facts. One thing that is a fact is that 250.104(A) has only one requirement for this bond and that is for it to be accessible.

Here's where I see things having gone terribly astray. 250.4(A)(4) Bonding of Electrically Conductive Materials and Other Equipment talks about electrically conductive materials that are likely to become energized. 250.104(B) also mentions the phrase "that may become energized". However, this wording was not included in 250.104(A)(1). Why?

250.4 in its entirety is talking about electrical conductive material and electrical equipment and it is not addressing the grounding electrodes, metal air ducks, metal waste pipes, metal drain pipes, metal air pipes, metal sprinkler pipes nor metal water pipes. These are addressed in 250.52 and 250.104.

It's been that way a long time, so I find it hard to reason that it was an accidental omission. Maybe (as I also mentioned earlier) this is either a case of poor code writing, or poor substantiation. I'm willing to believe that the intention is to have all of the metal water piping system bonded. Therefore, it's not necessary to mention the likelyhood of becoming energized or to bond around items that interrupt the continuity. Those are givens. I'm also willing to listen to anybody who can show me that this was never the intent of the code.

The fact that it has been written in the code like this for at least the past 44 years is the reason for my question in the first place.
Here is what was said in the 1968 cycle of the code
http://i3.photobucket.com/albums/y63/jwelectric/250.jpg
Based on the 1968 cycle why are we not bonding all these thing mentioned therein based on 250.66? Could it be because it was only suggested in those years as it is today in the Fine Print Notes?

250.104(B)FPN FPN: Bonding all piping and metal air ducts within the premises will provide additional safety.

In 250.4 and 250.53(D) the panelist made a point to ensure that continuity was maintained in those sections. It is my opinion that the omission of this requirement in 250.104 was not an oversight on the part of the panel and was never intended to be part of the rule. I base this on the remarks from the panel as posted.
http://www.mikeholt.com/code_forum/showpost.php?p=603046&postcount=33
I am also of the belief that if it is copper pipes that installed and the bonding is required to be kept continuous then a jumper would be required at each soldered joint based on
250.8 Connection devices or fittings that depend solely on solder shall not be used.
Would the cast-iron drains and waste pipes installed in days gone by be required to have jumpers around their joints?

I am looking for something a little more concrete than a guess, opinion or belief. Give me something that would substantiate the need for a jumper sized by the service conductors. Show me how this much current can ever get on the water line that in not part of the grounding electrode system.

I am trying to remain open minded on this subject and will entertain any comment that shows a need for this bonding. I can?t see any reason for such strenuous requirements especially when renovating old buildings into apartments with a large service and the water pipes are metal. A 600 amp main would require a 3/0 jumper at each water heater. Tell me how this much money can be substantiated. This is one situation where the inspector would have to have something in writing that was very clear in order to enforce this requirement don?t you think?

 

[jwelectric]

One other chafing point I have: I submitted a proposal to change 250.104, and then another for 250.104(A)(1).

Either I somehow forgot to print it (because I'm looking at it right now on my computer, all ready to go) or they lost it. The answer to the proposal might have shed more light on this.

I had a student from DCCC that submitted a proposal on 250.104(A)(1) that is not there. I cannot say that it was mailed due to the fact that the school mailed all the proposals at one time but I do have a copy of his proposal in my files.

By the way I like the way that you have put part of my name beside yours in your signature -George Stolz, J.W.- a job well done my friend, I am proud of you!

 

[George Stolz]

Hmm. I smell a conspiracy.

BTW, the J.W. in my signature does not stand for Joe Whitt, but is actually a reference to my somewhat eccentric eating habits: Just Walnuts.

 

[mvannevel]

So to follow what you are saying, a system that has nonmetallic pipe but does have metallic stubs a bonding conductor sized by 250.66 would need to be installed at each stub and bonded back to the service. This would ensure that all metal pipes are bonded.

No, not at all. That would not constitute a metal piping system, and wouldn't require bonding to those metal stubs.

What I am looking for is something concrete that will take all the guess work out of the facts. One thing that is a fact is that 250.104(A) has only one requirement for this bond and that is for it to be accessible.

Actually, to me, there are two requirements. One is to bond the system, and the other is that the bonding be accessible. But I've got to agree that it would be nice to find something that takes the guesswork out of this.

250.4 in its entirety is talking about electrical conductive material and electrical equipment and it is not addressing the grounding electrodes, metal air ducks, metal waste pipes, metal drain pipes, metal air pipes, metal sprinkler pipes nor metal water pipes. These are addressed in 250.52 and 250.104.

Yes, but you'll notice that 250.4(A)(4) is Bonding of Electrically Conductive Materials and Other Equipment. I'd say that the metal water piping system falls into this category. And 250.4 contains the General Requirements for Grounding and Bonding. These are then modified by the requirements found in 250.104.

In 250.4 and 250.53(D) the panelist made a point to ensure that continuity was maintained in those sections. It is my opinion that the omission of this requirement in 250.104 was not an oversight on the part of the panel and was never intended to be part of the rule. I base this on the remarks from the panel as posted.

Panel Statement: The requirements of 250.104(A) apply to complete metallic water piping systems. Where there is no complete metallic water piping system, then the requirements of 250.104(B) would apply for those portions of isolated metal water piping system likely to become energized.

This is where it gets curiouser and curiouser to me. Do they mean to say that if a metallic water piping system has an insulating joint or a short non-metallic pipe at some point, that its not a complete system and therefore doesn't fall under 250.104(A) at all? Does it then follow that we needn't bond it at all? If we follow the wording of 250.104(B) and it's not likely to be energized I'd guess not. But then to follow their logic, does 250.104(B) only apply to complete piping systems as well? I don't see the word "complete" in either one of those sections.

I am looking for something a little more concrete than a guess, opinion or belief. Give me something that would substantiate the need for a jumper sized by the service conductors. Show me how this much current can ever get on the water line that in not part of the grounding electrode system.

I'm looking for that concrete evidence myself. I'd guess we'd need to see their substantiation for the bonding conductor to that water pipe in the first place. Then explain why it needs to be based on the service conductors. And then explain if and why a bonding jumper would be required and how it should be sized.

Bottom line here Mike, is that in the absence of a formal interpretation we just don't really know for sure. I'm still of the opinion that this is yet another case of sloppy code writing. This is either important enough to spell out in detail what the exact requirements are, or it needs to go away completely because it serves no purpose. This type of thing (and it's in no way uncommon) is frustrating for electricians and inspectors alike.

I'm planning on talking to some of my fellow inspectors at our Metro Inspectors meeting tomorrow. I'll be interested to hear their opinions on this. I'm also going to see what kind of answers I can get at the IAEI Western Section meeting next month. If for no other reason, to see how many require bonding around these items and how many don't.