Bonding the Hot Water pipe.

Status
Not open for further replies.

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
Just for the record. Here is an email from Ron -- our nc state inspector on the issue.

Hi Dennis,

We look at how much is metallic, if the majority is metal, 51%, then it must be bonded. Even though a lesser amount might not warrant bonding by the State Electrical Code, it?s a good idea to bond it.

Ron

That was today so perhaps I didn't use the exact words but I got his drift. For the others, this has no meaning in terms of what the NEC states. I just am saying that this is Ron's unofficial word.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
Just for the record. Here is an email from Ron -- our nc state inspector on the issue.
Hi Dennis,

We look at how much is metallic, if the majority is metal, 51%, then it must be bonded. Even though a lesser amount might not warrant bonding by the State Electrical Code, it?s a good idea to bond it.

Ron


That was today so perhaps I didn't use the exact words but I got his drift. For the others, this has no meaning in terms of what the NEC states. I just am saying that this is Ron's unofficial word.

Mike, looks like you need to have a word with Ron. :grin:

Roger
 

jwelectric

Senior Member
Location
North Carolina
Bob I made the statement
There is no requirement to make a metal piping system electrically continuous. If for any reason someone feels that a jumper should be installed somewhere to ensure continuity then the piping system must not be a complete metallic system and would fall under 250.104(B)

Then you asked
Is this a code fact or an opinion?
Then I said
Well Bob can you show a requirement that the metal pipes are required to be electrically continuous? If not then I would assume that there is no such requirement especially sense it was once very clear that the metal pipes were once required to be electrically continuous as outlined in this 1975 code section

Now you make this statement
So as always you refuse to just answer the question. I figured as much when I asked it.

What is funny is that I have not stated my position on this issue and you seem to be assuming that you know my position.
of which I just can't make sense of.

What does make sense is that once way back there was verbiage that a code enforcement official could use to enforce continuity of a metal water pipe and that today this verbiage is missing unless you know of a place it can be found.

I am not assuming anything about your position I am simply answering your question concerning the code.

now once again I am saying unless you can point to a section requiring a metal water pipe be electrically continuous then no requirement exist.
 

jwelectric

Senior Member
Location
North Carolina
Mike, looks like you need to have a word with Ron. :grin:

Roger

I have not yet talked with Ron but was thinking about this today. If Ron says that the pipe must comprise 51% of the system then in most cases this would leave all the isolated hot water pipes out of the picture simply because there is more cold water pipes than hot in most cases. At any rate the part that is less than 50% would not require any bonding. Yes, No??:confused:
 

iwire

Moderator
Staff member
Location
Massachusetts
Bob I made the statement

Then you asked

Then I said
[/SIZE]
Now you make this statement
of which I just can't make sense of.

What does make sense is that once way back there was verbiage that a code enforcement official could use to enforce continuity of a metal water pipe and that today this verbiage is missing unless you know of a place it can be found.

I am not assuming anything about your position I am simply answering your question concerning the code.

now once again I am saying unless you can point to a section requiring a metal water pipe be electrically continuous then no requirement exist.

Mike it was a yes or no question, why can't you just answer it?

Here is is again, maybe you can answer it this time


There is no requirement to make a metal piping system electrically continuous. If for any reason someone feels that a jumper should be installed somewhere to ensure continuity then the piping system must not be a complete metallic system and would fall under 250.104(B)

Is this a code fact or an opinion?
 

jwelectric

Senior Member
Location
North Carolina
This is a fact. Is it not you who taught us that the NEC is a permissive code? Have you changed your mind? I am sure that you of all people understand what a mandatory rule is. Point out the ?shall be made electrically continuous? as was printed in the 1975 code cycle.
Unless you can show verbiage that clearly states that the metal pipes of a building are to be made electrically continuous then there is no such requirement

Now Bob it is your turn to answer a question. Can you show text requiring a metal water pipe to be made electrically continuous? I am not asking for a yes or no answer but just that you show such text.

Look at 250.52(A)(1) where the metal water pipe is used as an electrode. There is a requirement to make the metal water electrode electrically continuous. 250.64 the raceway for the grounding electrode is required to be electrically continuous. 250.98 where raceways are required to be electrically continuous. 250.118 where raceways used as the equipment grounding conductor are required to be made electrically continuous.
But there is not one word that requires a metal water pipe to be made electrically continuous. By the way I am waiting for someone to bring up 250.32 and a SDS
 

dbuckley

Senior Member
The FPN of 250.104(B) gives a damned fine hint about how the installing EC should approach the situation (with my added emphasis):

Bonding all piping and metal air ducts within the premises will provide addtional safety

John in a post above, says this:

It is my understanding that the reason we bond hot to cold is to keep everything at the same potential.

And thats absolutely correct. All bits of metal within an electrical environment (eg a home) should all be bonded to ensure that a potential difference cannot arise between different conductive surfaces.

So if there is any doubt if the plumbing is a single metallic conductive element, then it needs multiple bonding points for all plumbing to be "bonded", otherwise the plumbing (clarity: when I say "the plumbing" I mean "all plumbing") is not bonded, even if you've bonded it somewhere.

The integrity of the bonding should survive even in the case of forseeable maintenance. If a plumber takes out the hot water tank to replace it, does that destroy the integrity of the bonding? Plumbers do remove and replace tanks, filters, boilers, and other things, and the removal of these things should not compromise the bonding (and thus the safety) of the electrical envronment.

Someone posted a picture last year he took whilst on holiday in the UK, showing a bond between the hot and cold pipes below a sink, and labelled it "excessive". (Of course, I cant find the post now). I don't consider it "excessive", I think its the work of an electrican who understand the risk that electricity poses, and is reducing the risks to the homeowner.
 

iwire

Moderator
Staff member
Location
Massachusetts
And thats absolutely correct. All bits of metal within an electrical environment (eg a home) should all be bonded to ensure that a potential difference cannot arise between different conductive surfaces.

I am pretty sure you don't really mean what you typed.
 

iwire

Moderator
Staff member
Location
Massachusetts
This is a fact. Is it not you who taught us that the NEC is a permissive code? Have you changed your mind? I am sure that you of all people understand what a mandatory rule is. Point out the ?shall be made electrically continuous? as was printed in the 1975 code cycle.
Unless you can show verbiage that clearly states that the metal pipes of a building are to be made electrically continuous then there is no such requirement

You still can't seem to admit that what you post is just opinion and nothing more.
The only fact is AHJs interpret the rules differently and none of our posts are any more than personal opinions and our own interpretations.

Now Bob it is your turn to answer a question. Can you show text requiring a metal water pipe to be made electrically continuous? I am not asking for a yes or no answer but just that you show such text.

No, I cannot.

But then again I never offered any opinion that indicated such text existed did I?
 

jwelectric

Senior Member
Location
North Carolina
90.5(C) Explanatory Material. Explanatory material, such as references to other standards, references to related sections of this Code, or information related to a Code rule, is included in this Code in the form of fine print notes (FPNs).
Fine print notes are informational only and are not enforceable as requirements of this Code.

I haven?t said that it is a bad idea but I still maintain that there is no verbiage to enforce making a metal water pipe electrically continuous. There is no verbiage to bond metal duck work either.

Bonding the metal water pipe has absolutely nothing to do with equipotential bonding or a touch potential but instead it is a fault path to clear any currents carried by the metal water pipe.

The NEC does not address the installation of a plumbing system therefore you will find nothing in the NEC that addresses making the plumbing system electrically continuous. Should there be a need to address the plumbing of a building that would be covered in the plumbing code.

There is nothing in the plumbing code to prohibit a plumber from repairing a metal pipe with a nonmetallic repair. The plumber is not allowed (at least in NC) to install an electrical circuit or anything pertaining to the electrical trade therefore no requirement for the plumber to make the metal water pipe electrically continuous.
The electrician is not allowed to do plumbing (at least in this state) therefore there is no requirements for the electrician to ensure that the plumbing to be electrically continuous.

If I am mistaken here would someone please set me straight and show me this requirement to make the metal plumbing pipes electrically continuous. I do know that in the 1975 Edition of the NEC in 250-80 was clear language that the metal piping system had to be electrically continuous (don?t have the ?78) and by the 1981 Edition of the NEC this requirement had been removed.
 

dbuckley

Senior Member
I am pretty sure you don't really mean what you typed.
I mean pretty much what I typed.

When I did thus stuff, not in the USA and subject to the NEC, the rules said one needed to bond:
water services pipes (note plural)
gas instalation pipes
other service pipes and ducting
central heatring and air conditioning systems
exposed metallic parts of the building
the lightning protection system
telecomms cables sheaths where conductive

And any "extraneous conductive parts". Definition is "a conductive part liable to introduce a potential, generally earth potential, and not forming part of an electrical installation. So something metallic, not part of the building fabric, but installed, such as a metal countertop, that all its plumbing uses PVC pipes, would generally be considered in need of bonding.

Outside of the obvious examples, a more useful and easy to use derived approach is if the resistance between something conductive and the electrical ground is 22Kohm or less, it needs to be bonded.

And... something totally different for iwire - I saw this lot's truck the other day :)
 
Last edited:

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
This discussion has gone from, bonding across the water heater from cold water pipes to hot water pipes, to bonding short sections of metal pipe to make it continuous. Very different in my opinion.

Now what is a metal piping system? In some peoples eyes it is 100% complete system. So I ask this question if the cold water lines are continuous 100% then I believe we all agree it needs bonding. Now if the water heater is installed with, say, a dielectric fitting the one could argue that we have 2 piping systems, ie, one for the cold water and one for the hot. This would then req. both the hot and cold to be bonded. Personally I have never seen a dielectric fitting on a water heater however it probably is not a bad idea to jump to the hot water to protect a plumber when the water heater gets changed.

IMO, the nec does not req. a jumper but I can see the hot and cold being 2 systems if there is a dielectric fitting.

Mike , I don't think any of us thionks the NEC requires plumbing pipe to be continuous but it does req. metal piping systems to be bonded.
 

izak

Senior Member
Location
Springfield, MO
A.O. Smith water heaters come with Dielectric fittings installed on hot and cold sides.
VERY tightly I might add

Every water heater ive installed in the last 10 years has shipped with them, and the instructions generally call for them to be installed. I believe sometimes it is a warranty issue as well.

We bond hot to cold here all over arkansas at the water heater, and we dont complain about it. It costs about 4 dollars more and 45 seconds to do.
 

izak

Senior Member
Location
Springfield, MO
I feel like this thread is become more of an ASSAULT than a useful discussion of any type,

and kinda gotta wonder about the home life of the OP as he seems capable of printing more than 70% of the text contained in this 8 PAGE ASSAULT.

Just saying... maybe spending too much time on the Internet?


and Yes, George, I sorta expect to be censored on this one
 

roger

Moderator
Staff member
Location
Fl
Occupation
Retired Electrician
and kinda gotta wonder about the home life of the OP as he seems capable of printing more than 70% of the text contained in this 8 PAGE ASSAULT.
I think you need to look again, the OP only has two posts in this thread.

Roger
 

jwelectric

Senior Member
Location
North Carolina
This discussion has gone from, bonding across the water heater from cold water pipes to hot water pipes, to bonding short sections of metal pipe to make it continuous. Very different in my opinion.
For the record I am only addressing the bonding across a water heater.


Now what is a metal piping system? In some peoples eyes it is 100% complete system. So I ask this question if the cold water lines are continuous 100% then I believe we all agree it needs bonding. Now if the water heater is installed with, say, a dielectric fitting the one could argue that we have 2 piping systems, ie, one for the cold water and one for the hot. This would then req. both the hot and cold to be bonded. Personally I have never seen a dielectric fitting on a water heater however it probably is not a bad idea to jump to the hot water to protect a plumber when the water heater gets changed.
Being that there is no definition for water pipes in the NEC I use the definition outlined in the code that mandates the installation of plumbing pipes and it says that there is only potable water. The plumbing codes does not call it two piping systems one being hot the other being cold but clearly states that at a fixture where water will be used for washing, cooking or for humans to consume only potable water is allowed to be connected. It does not say potable cold and potable hot.


IMO, the nec does not req. a jumper but I can see the hot and cold being 2 systems if there is a dielectric fitting.
only one potable water system. Both the hot and cold are of the same system. Both come from the same place.


Mike , I don't think any of us thionks the NEC requires plumbing pipe to be continuous but it does req. metal piping systems to be bonded.
On this we both agree where the disagreement comes is with a bunch of electricians trying to discuss just what the plumbing codes call a potable water system. As electricians and electrical inspectors we think we know more about plumbing than the plumbing codes. Now don?t take this personal as I am talking about people in general here. Electricians seem to think that the water in the cold water pipe is different than water in the hot water pipe. It is all part of the potable water ?system?.
 

iwire

Moderator
Staff member
Location
Massachusetts
only one potable water system. Both the hot and cold are of the same system. Both come from the same place.

Again, that is what is known as an opinion. An opinion is not the same as a fact.

Using the logic of 'both come from the same place' would mean that a building with multiple transformers would only have one voltage system because 'they all come from the same place'.
 

jwelectric

Senior Member
Location
North Carolina
Again, that is what is known as an opinion. An opinion is not the same as a fact.

Using the logic of 'both come from the same place' would mean that a building with multiple transformers would only have one voltage system because 'they all come from the same place'.

Now Bob as much as I like you, you sometimes say things that just don?t make a lick of sense. How can you compare water to electricity when it comes to the codes? How does it become logical that there is more there than what the plumbing codes mandate?
The ICC plumbing code call all the water that comes out of the faucet of your kitchen sink ?potable water? and does not distinct the difference between cold and hot. It is the plumbing codes that regulate the rules for water systems and it is the plumbing code that calls it all potable water. Now unless you are trying to say that the plumbing codes don?t know what they are talking about then I must accept that the hot and cold potable water does not constitute two separate systems but are indeed the same potable water system.
So it is not my opinion but the opinion of the ICC that there is only one system and it is called the potable water system not the potable cold water system and the potable hot water system.

To compare a building that has step down or step up transformers as having ?voltages? that come from the same place is nothing short of a joke. The voltage that is on the primary side is a lot different than the voltage on the secondary side.
The water that comes to a heater is the same water that is going out of the heater. The water is the same just with a different temperature. The water going into the water heater is potable water and the water coming out is potable water. Now you might have a point if potable water was going in and either waste or gray water was coming out.

As a side note when I first read this I asked myself just who is posting under Iwire?s name.
 
Status
Not open for further replies.
Top