Bonding and Grounding Copper Pipes

[ptonsparky]

Non GFCId circuits will energize that section, if it is not bonded. Short sections of piping are not required to be bonded and are not likely to be energized. At one time we were allowed to run an EG to a metallic water line when adding a receptacle to an existing two wire circuit. At that time the water line could be bonded at any point and Pex wasn't heard of. Those EG bonds to the pipe increased the likely hood of it carrying current during fault conditions and normal operation, depending on what was being used.

Safeguards would be GFCI protection and workmanship by all trades.

 

[gadfly56]

Since you all have been so good about answering my questions (and I can’t tell you how appreciative I am for your help and insight), I have another one. What happens when a bare wire touches a metallic pipe anywhere in the house? What safeguards are in place when something like this happens?

Assuming that this is an all-metal pipe system and all the proper bonding/grounding has been done, and it's the hot wire, if you listen carefully, you'll hear the circuit breaker pop. This will de-energize the wire. If it's the neutral wire it won't pop because the neutral is carrying the return current only, which is presumably below the current rating of the circuit breaker or the breaker would have already tripped. If it is the neutral wire, it will also become a parallel return of the current to the panel. Now, if you make a separate connection to "ground" by grabbing the pipe, you may or may not get a tingle, depending on the resistance provided by your body and shoes to ground. If there is a ground fault circuit interrupter (GFCI) involved, it should trip if the current through you is over 4-5 mA. Current takes all paths back to its source, but some paths are a lot easier than others. At least, that's my understanding of things. If I've goofed, someone will correct me.

 

[gadfly56]

What water heater bonding jumper? Where have you ever seen that??

-Hal

Here? And I know for a fact that the plumber made the attachment, since this is my house and this was after the water heater was replaced.

 

[Bro8898]

Non GFCId circuits will energize that section, if it is not bonded. Short sections of piping are not required to be bonded and are not likely to be energized. At one time we were allowed to run an EG to a metallic water line when adding a receptacle to an existing two wire circuit. At that time the water line could be bonded at any point and Pex wasn't heard of. Those EG bonds to the pipe increased the likely hood of it carrying current during fault conditions and normal operation, depending on what was being used.

Safeguards would be GFCI protection and workmanship by all trades.

Thank you for your response. I’m finally starting to understand what’s going on when plumbers disconnect pipes. It’s not a fault from a wire touching a pipe that I need to be worried about, it’s that the utility neutral has been lost somewhere and now it’s flowing into the house from the common metallic water main

 

[winnie]

DIY report, but one of the things I learned early on was to have a bonding jumper from hot to cold across the water heater, and when I did the plumbing and electric in my house I added such.

-Jon

 

[Bro8898]

Assuming that this is an all-metal pipe system and all the proper bonding/grounding has been done, and it's the hot wire, if you listen carefully, you'll hear the circuit breaker pop. This will de-energize the wire. If it's the neutral wire it won't pop because the neutral is carrying the return current only, which is presumably below the current rating of the circuit breaker or the breaker would have already tripped. If it is the neutral wire, it will also become a parallel return of the current to the panel. Now, if you make a separate connection to "ground" by grabbing the pipe, you may or may not get a tingle, depending on the resistance provided by your body and shoes to ground. If there is a ground fault circuit interrupter (GFCI) involved, it should trip if the current through you is over 4-5 mA. Current takes all paths back to its source, but some paths are a lot easier than others. At least, that's my understanding of things. If I've goofed, someone will correct me.

This is more good information. Thank you. It sounds like a “bare” wire energizing a pipe is not nearly as much of a concern as the utility losing its neutral somewhere. At least from a plumbing perspective, it seems that the circuit breaker will take care of a pipe becoming energized to faulty wires. On the other hand, dealing with neutral current coming from the water main (which is something I have no way of knowing whether it is or is not happening) seems to be something that I need to be doing everything I can to work around by using a proper jumper in almost all cases. Thank you for answering these questions. That’s exactly what I came here looking for

 

[synchro]

Here? And I know for a fact that the plumber made the attachment, since this is my house and this was after the water heater was replaced.

View attachment 2554722

Bonding jumpers across the hot and cold are intended to maintain continuity when dielectric unions are used to combat corrosion due to electrolysis between dissimilar metals (in this case copper pipes and the steel tank).

 

[Bro8898]

Bonding jumpers across the hot and cold are intended to maintain continuity when dielectric unions are used to combat corrosion due to electrolysis between dissimilar metals (in this case copper pipes and the steel tank).

Would the only time you need a bonding jumper on the water heater hot and cold be when the bond wire lands downstream of the water heater?

Also, I’ve heard the reason plumbers do that (although never seen it done myself) is to extend the life of the weather heater?

So is it a safety feature or is it to extend the life of the equipment? We could be talking about 2 different things

 

[kwired]

Would the only time you need a bonding jumper on the water heater hot and cold be when the bond wire lands downstream of the water heater?

Also, I’ve heard the reason plumbers do that (although never seen it done myself) is to extend the life of the weather heater?

So is it a safety feature or is it to extend the life of the equipment? We could be talking about 2 different things

From NEC perspective we are supposed to bond metallic water piping systems as well as other metallic piping systems. There is somewhat different rules for water piping vs other piping though and is mostly regarding size of bonding conductor required. Even interior metal water piping that isn't connected to metallic underground supply needs bonded - The idea is it will only energize piping long enough to trip overcurrent device instead of leaving the piping energized. Gas piping and other metallic piping typically only needs to be bonded by the equipment grounding conductor of whatever circuit is likely to energize the piping, water piping bond needs sized to incoming electric service conductors, they must figure there are more possible ways a water piping system is likely to become energized I guess.

Bonding around water heaters isn't exactly a NEC rule. The rule is basically to bond around items that are subject to more frequent opening for replacement or around anything that has insulating fittings or isolated sections of non metallic piping. Water heaters often will have dielectric unions and strictly going off NEC wording things like shower mixing valves or water softener bypass loops in an entirely metallic piping system still bonds between hot/cold, hard/soft water lines and a wire jumper isn't needed. But many local AHJ's still write amended rules that state they want to see a wire bonding jumper around water heaters, maybe even water softeners in those instances. some also do the same for gas piping, even though NEC allows the equipment ground conductor for say the furnace to bond the gas pipe if that furnace is the only branch circuit that has likelihood of energizing it.

And yes you generally need to be more concerned with neutral current to/from the street side piping than from interior piping. Unless the inside piping is incorrectly connected to a neutral current carrying conductor there should only be current in said piping during fault situations that should also be tripping an overcurrent device and only for seconds at the most.

 

[hbiss]

What happens when a bare wire touches a metallic pipe anywhere in the house? What safeguards are in place when something like this happens?

Bare as in hot or energized? The answer is an all metallic piping system will be part of and connected to the water service which should be bonded to the neutral as we have been discussing. So if an energized conductor contacts a water pipe the breaker for the associated circuit should trip.

I know the question will come up about piping systems that are not continuously metallic. With PEX and copper fixture stubs, those fixtures and stubs are not required to be bonded because it is unlikely that they could become energized. However, larger metallic sections that may have been re-fed with PEX need to be bonded.

There is no reason to bond the hot and cold lines on a water heater simply because the water heater itself is metallic.

Gas lines should never be bonded except for the CSST that requires bonding for lightning pinhole protection.

But pressure reducing valves have them too and I know they don’t have dielectric fittings. Maybe it’s the idea that someone is going to be replacing the prv in the future and the pipe will be broken.

Around here we bond around the water meter on the premise that it could be replaced with a plastic one. That's the only reason.

Maybe it’s the idea that someone is going to be replacing the prv in the future and the pipe will be broken.

I'm trying to get across to you that current or voltage on a piping system is an anomaly. If it is present it's usually due to a dangerous electrical condition that was caused by neglect or somebody who didn't know what they were doing. Nobody designs a plumbing system with it being required to carry electrical current in mind. Not that you shouldn't use due diligence, but the activity of a plumber shouldn't require considering plumbing systems to be energized. And if in the course of your work electrical damage occurs, that's not your responsibility. Matter of fact the owner should be held liable if you are injured for allowing a hazardous or dangerious condition to exist.

-Hal

 

[LarryFine]

Bare as in hot or energized? The answer is an all metallic piping system will be part of and connected to the water service which should be bonded to the neutral as we have been discussing. So if an energized conductor contacts a water pipe the breaker for the associated circuit should trip.

And this is preferable to energizing the plumbing system.

 

[gadfly56]

Would the only time you need a bonding jumper on the water heater hot and cold be when the bond wire lands downstream of the water heater?

Also, I’ve heard the reason plumbers do that (although never seen it done myself) is to extend the life of the weather heater?

So is it a safety feature or is it to extend the life of the equipment? We could be talking about 2 different things

No, you should always have one, on the assumption that dielectric couplings are being used to connect the water tank (which they should be). If you don't, then the entire hot water distribution system is not bonded.

 

[don_resqcapt19]

No, you should always have one, on the assumption that dielectric couplings are being used to connect the water tank (which they should be). If you don't, then the entire hot water distribution system is not bonded.

I have never seen a wire type jumper in my area, but I know some areas require them.

The majority of tub and shower mixing valves are still metal, and they provide the required connection between the hot and cold water lines without a wire jumper at the water heater. Of course that assumes that the valve bodies are connected to the metal water pipes...some are connected with non-metallic flex connections.

 

[kwired]

Facing some reality, isn't most this about how to deal with existing installations? Anymore the entire plumbing systems are non metallic on new installs, maybe with some very limited metallic sections here or there that are isolated enough they would not require bonding to main electrical system - might already be bonded to an EGC of equipment they are associated with though.

 

[hbiss]

No, you should always have one, on the assumption that dielectric couplings are being used to connect the water tank (which they should be)

Didn't we talk about that some time ago? According to what was discussed, dielectric nipples on water heaters are metallic and are only plastic lined on the inside. So they wouldn't interrupt the electrical continuity between them and the tank.

-Hal

 

[Bro8898]

From NEC perspective we are supposed to bond metallic water piping systems as well as other metallic piping systems. There is somewhat different rules for water piping vs other piping though and is mostly regarding size of bonding conductor required. Even interior metal water piping that isn't connected to metallic underground supply needs bonded - The idea is it will only energize piping long enough to trip overcurrent device instead of leaving the piping energized. Gas piping and other metallic piping typically only needs to be bonded by the equipment grounding conductor of whatever circuit is likely to energize the piping, water piping bond needs sized to incoming electric service conductors, they must figure there are more possible ways a water piping system is likely to become energized I guess.

Bonding around water heaters isn't exactly a NEC rule. The rule is basically to bond around items that are subject to more frequent opening for replacement or around anything that has insulating fittings or isolated sections of non metallic piping. Water heaters often will have dielectric unions and strictly going off NEC wording things like shower mixing valves or water softener bypass loops in an entirely metallic piping system still bonds between hot/cold, hard/soft water lines and a wire jumper isn't needed. But many local AHJ's still write amended rules that state they want to see a wire bonding jumper around water heaters, maybe even water softeners in those instances. some also do the same for gas piping, even though NEC allows the equipment ground conductor for say the furnace to bond the gas pipe if that furnace is the only branch circuit that has likelihood of energizing it.

And yes you generally need to be more concerned with neutral current to/from the street side piping than from interior piping. Unless the inside piping is incorrectly connected to a neutral current carrying conductor there should only be current in said piping during fault situations that should also be tripping an overcurrent device and only for seconds at the most.

In my own house the prv has a jumper around it. The lower clamp in the pic is where the wire connects to the breaker box. That’s where the water is coming in the house. Where it connects above the prv would be “downstream” of it. Was that jumper wire necessary? It seems since the bonding wire connects before (or upstream) of the prv then no jumper is needed for equipment located downstream. What do you think?

 

[Bro8898]

Bare as in hot or energized? The answer is an all metallic piping system will be part of and connected to the water service which should be bonded to the neutral as we have been discussing. So if an energized conductor contacts a water pipe the breaker for the associated circuit should trip.

I know the question will come up about piping systems that are not continuously metallic. With PEX and copper fixture stubs, those fixtures and stubs are not required to be bonded because it is unlikely that they could become energized. However, larger metallic sections that may have been re-fed with PEX need to be bonded.

There is no reason to bond the hot and cold lines on a water heater simply because the water heater itself is metallic.

Gas lines should never be bonded except for the CSST that requires bonding for lightning pinhole protection.



Around here we bond around the water meter on the premise that it could be replaced with a plastic one. That's the only reason.



I'm trying to get across to you that current or voltage on a piping system is an anomaly. If it is present it's usually due to a dangerous electrical condition that was caused by neglect or somebody who didn't know what they were doing. Nobody designs a plumbing system with it being required to carry electrical current in mind. Not that you shouldn't use due diligence, but the activity of a plumber shouldn't require considering plumbing systems to be energized. And if in the course of your work electrical damage occurs, that's not your responsibility. Matter of fact the owner should be held liable if you are injured for allowing a hazardous or dangerious condition to exist.

-Hal

Wow thank you for that response. That is very good info for when I get out on my own. I needed that. Thanks again

 

[kwired]

View attachment 2554737 In my own house the prv has a jumper around it. The lower clamp in the pic is where the wire connects to the breaker box. That’s where the water is coming in the house. Where it connects above the prv would be “downstream” of it. Was that jumper wire necessary? It seems since the bonding wire connects before (or upstream) of the prv then no jumper is needed for equipment located downstream. What do you think?

You may get mixed responses on the regulator there. Some may see it as something that likely needs removed or replaced frequently and feels it needs a bond around it others may not. Having a metallic body it shouldn't need additional bonding around it other than because of frequent opening the continuity. I sort of feel this not necessary with water meters myself, but many think we should. IMO that mostly goes back to when you could run the grounding electrode conductor to anywhere on the piping that it was necessary to bond around the meter. Now just make sure you bond on street side of the meter IMO should be sufficient. Meters don't get removed all that frequently. Usually only if they seem to not be registering correctly, or more recent years to replace with one that has remote read capabilities.

 

[gadfly56]

Didn't we talk about that some time ago? According to what was discussed, dielectric nipples on water heaters are metallic and are only plastic lined on the inside. So they wouldn't interrupt the electrical continuity between them and the tank.

-Hal

You may well be correct, but I don't recall that thread myself. Which, if true, makes me wonder why the plumber added the jumper.

OK, I just did a Google search, and it turns out that there is a gasket between the two metals in the union, so there appears to be no bond through the shell of the water heater.

 

[kwired]

You may well be correct, but I don't recall that thread myself. Which, if true, makes me wonder why the plumber added the jumper.

OK, I just did a Google search, and it turns out that there is a gasket between the two metals in the union, so there appears to be no bond through the shell of the water heater.

He was talking about a nipple you were talking about a union. There is a difference in continuity of the outer portion there. Nipple is metallic, not sure what kind of metal but apparently something that won't have galvanic corrosion between it and the steel hub on the tank nor to a copper fitting on the outgoing line, but shouldn't interrupt electrical continuity either.