Water line bonding vs GEC

[hornetd]

So a metallic piping system going to and leaving from needs a jumper at the water heater?

If it is an electric water heater then yes. The code says that any metallic piping that is likely to become energized must be bonded. Such piping attached to an electric water heater fits that description. No matter which side of the connected piping becomes energized we have to be sure that it will have a low impedance connection to the Equipment Grounding Conductor of the water heater's branch circuit. If you had some way of knowing that the 2 pipe connections were connected to each other you could call it done. Since you won't know that in most circumstanced you bond the 2 pipes to each other. Then if either pipe becomes energized the one that is connected to the EGC of the branch circuit will connect the other pipe run to the EGC of the water heater's branch circuit as well.

Tom Horne

 

[LarryFine]

Then if either pipe becomes energized the one that is connected to the EGC of the branch circuit will connect the other pipe run to the EGC of the water heater's branch circuit as well.

Then why can't the jumper be only #10cu?

Don't hot and cold have equal connectivity to the water heater?

 

[hornetd]

Not in my house. With the mixing valves in two showers, the double shut off at the washing machine and the mixing faucets in the utility sink, my hot and cold water piping are not separated.

Good quality water heaters have been glass or ceramic lined for decades. The piping ports may be metallic but that does not mean that there are connections to the EGC of the water heater from both or even either. To assure that any EGC connection to one pipe is also to the other you bond between them. Next time you encounter an as yet uninstalled water heater, and you have a continuity checker with you, check for continuity between the 2 piping ports and each piping port and the metal cover of the wiring compartment. What you will find will vary from brand to brand.

Tom Horne

 

[jim dungar]

Good quality water heaters have been glass or ceramic lined for decades. The piping ports may be metallic but that does not mean that there are connections to the EGC of the water heater from both or even either. To assure that any EGC connection to one pipe is also to the other you bond between them. Next time you encounter an as yet uninstalled water heater, and you have a continuity checker with you, check for continuity between the 2 piping ports and each piping port and the metal cover of the wiring compartment. What you will find will vary from brand to brand.

Tom Horne

I don't care about the water heater. I have at least 4 combined valves in my house that are metallic, with either threaded or soldered connections, which guarantee the cold and hot metallic pipes are joined electrically.

 

[hornetd]

Then why can't the jumper be only #10cu?

Don't hot and cold have equal connectivity to the water heater?

I don't think that I said it couldn't. If I did I was wrong. The code specifically says that the EGC of the supplying branch circuit shall be adequate to bond the piping. To take it a little further though it would be like a Grounding Electrode Conductor that connects one electrode, such as driven rods, to the Grounded Current Carrying Conductor. If I were going to connect a ground ring to the Driven Rod Electrode then I couldn't use the #6 copper that would be acceptable for a driven rod electrode. I have to use the size that is required for the Ground Ring. Since the minimum size of the ground ring conductor itself is #2 AWG copper and the Grounding Electrode Conductor for a Ground Ring must be at least the size of the ground ring conductor itself, I would have to run a #2 Copper GEC to the driven rod electrode in order to use the driven rod electrode as a connection point for the Ground Ring. Likewise imagine that the water line supplying cold water to the water heater also supplies an electrically heated "boiler." [If there is another term of art for such a "boiler" please let me know.] By bonding around the water heater I have made the hot water line just as likely to become energized as the cold water line supplying the water heater and the heating systems Water Heater. In this case I would think that using the same size conductor as the EGC/s of the branch circuit/s supplying the heating system to bond the piping at the water heater would be required.

Tom Horne

 

[hornetd]

I don't care about the water heater. I have at least 4 combined valves in my house that are metallic, with either threaded or soldered connections, which guarantee the cold and hot metallic pipes are joined electrically.

I do understand what you are saying even if my writing is not eloquent enough to make that clear. When we moved into our present house it had 1 full bathroom on the second floor. The mixing valve for the shower bath, bathroom sink, and the kitchen sink were the only ones in the house. The kitchen sink mixing valve had plastic guts but I did not think about that and I didn't check it for continuity because I didn't think of it as meeting the requirement for a bonding conductor. The valves for the clothes washer and the laundry sink were completely separate. Whether a mixing valve meets the bonding requirement or not I could see it functioning as one because the electrons don't care about the US National Electric Code (NEC).

[I know this because I conducted a careful survey of a billion electrons and they all responded that they don't give a tinkers damn about were electricians think they should go. They will go where the laws of physics send them. Or as one contributor to another electrical bulletin board says in his tag line "The laws of physics are strictly enforced."]

The rest of the question to me is, does a connection between the hot and cold water lines through a mixing valve 2 floors away conform to the requirement for a low impedance pathway back to the source of supply which is laid out in the objectives portion of Article 250. Obviously I don't think it does. I think that by "Low Impedance the code means the minimum practical impedance. I believe the intent is to use the shortest practicable pathway and not depend on plumbed appliances which may be conductive at the present time but not remain so in the future. When a water meter is connected to the plumbing by direct connection to conductive piping, and not by a water meter bracket, we have to bond around that water meter if we make a Grounding Electrode Conductor connection on the building side of the meter.

[As a side note I always try to make that connection on the street side of the very first shutoff in the building because neither the plumbers nor Harry and Harriet homeowner are likely to take apart and pipe they cannot shut off.]

In the same way I think that we should make bonding connections around any fitting or water using appliance that is not known to be electrically conductive.

Tom Horne

 

[Malywr]

He said house was built in mid 1970's. You may have to go to a cemetery to find that person and you will need to be pretty good talker to convince him to come fix it. If you are lucky enough to get someone that will talk back they have likely already retired.

Haha
Good point


Sent from my iPhone using Tapatalk

 

[LarryFine]

Haha
Good point

Not necessarily. I was born in '55 and had done plenty of electrical work by '75.

I did a fuses-to-breakers service upgrade for an uncle when I was 15 years old.

 

[ptonsparky]

Then why can't the jumper be only #10cu?

Don't hot and cold have equal connectivity to the water heater?

They do on every water heater I've had to work with.

eta: Granted the lining may be glass or enamel but tanks metal.

 

[Malywr]

Not necessarily. I was born in '55 and had done plenty of electrical work by '75.

I did a fuses-to-breakers service upgrade for an uncle when I was 15 years old.

Then your uncle needs to ask you to go back and correct his work so his license is safe

 

[LarryFine]

Then your uncle needs to ask you to go back and correct his work so his license is safe

He was my customer, not my boss, and I had no license yet, not even a driver's license.

I went back years later to add a genny and ATS, so I had the opportunity to critique my own work.

I'm proud to say that I passed my own inspection with flying colors.

 

[jim dungar]

Whether a mixing valve meets the bonding requirement or not I could see it functioning as one because the electrons don't care about the US National Electric Code (NEC).

No plumbing fitting needs to comply with the NEC for bonding.

My point is there us no reason to always have a jumper across the water heater, unless there is a specific state/local code requirement.
We can not future proof our installations.

 

[B&V Construction]

No plumbing fitting needs to comply with the NEC for bonding.

My point is there us no reason to always have a jumper across the water heater, unless there is a specific state/local code requirement.
We can not future proof our installations.

Here the inspectors will look for it, and that is reason enough. Do you want to have that argument? Yes if I just sweated hot and cold pipes into a brass shower valve body I know they're electrically connected. But no plumbing fixture is approved as a bonding jumper. If you accept that you are required to bond metallic piping in the house, then presumably you agree that said bonding must be accomplished using an approved technique. It's a few dollars worth of parts.

Inspectors here also look for black iron gas pipe to be bonded to the GES. If you have a case of an electric furnace/water heater (say heat pump units) with a gas cooktop, then you can bond to the EGC on the circuit serving the gas appliance. But if the house has a gas water heater they'll expect to see gas piping bonded to the water pipe. By local convention this bonding is typically done near the water heater. I would not be willing to get into an argument with an inspector about this either.

 

[jim dungar]

Here the inspectors will look for it, and that is reason enough. Do you want to have that argument? Yes if I just sweated hot and cold pipes into a brass shower valve body I know they're electrically connected. But no plumbing fixture is approved as a bonding jumper. If you accept that you are required to bond metallic piping in the house, then presumably you agree that said bonding must be accomplished using an approved technique. It's a few dollars worth of parts.

You need to follow your local rules, but not all localities are the same.

If plumbing fixtures cannot be considered as creating a single metallic piping system, do you place jumpers around all shutoff/isolation valves?

 

[kwired]

How does that make your point? I don't believe it does.



Huh? The section title you quoted above says the exact opposite. "GEC ... Connection to Grounding Electrodes.



Nothing in 250.68 or 250.52(A)(1) or the article 100 definition of a Grounding Electrode supports your assertion that only the below-ground portion of the grounding electrode object counts as the grounding electrode. That seems to be the premise your relying on, and unless you've got a different section to cite, the code doesn't actually say that.

When I buy an 8ft ground rod it comes to me 8'-3" so I can drive it 8ft in the earth and still have 3" accessible (a requirement) for my GEC connection. Is my connection at the top 3" above ground to something other than the electrode? C'mon man. Hundreds of ground rods inspected by the same guys who made me run those water pipe GECs 3/4 of the way around the house, and none of them ever contended something like that.

Mind you, I don't think the common interpretation would necessarily be a bad rule. But the code doesn't actually say it.

IMO the within 5 foot of entry simply means any pipe beyond 5 feet is not considered part of the electrode. You still must have at least 10 feet of metallic pipe in the ground or it is not a qualifying electrode, just like your mentioned ground rod must have at least 8 feet of it in the ground.

Now I have to measure the ground rods I typically use to see just how long they are. But they fit nearly perfectly in 8 foot truck bed so guessing they are right at 8 feet.

 

[jaggedben]

The ratio of opinion as compared to arguing from code language in this thread ...

 

[ptonsparky]

The ratio of opinion as compared to arguing from code language in this thread ...

And you expected this to be different?

 

[B&V Construction]

You need to follow your local rules, but not all localities are the same.

If plumbing fixtures cannot be considered as creating a single metallic piping system, do you place jumpers around all shutoff/isolation valves?

If it's a metallic valve connecting two metal pipes then I wouldn't, because there's no requirement to do so. If the valve truly created an electrically isolated water piping subsystem then I would, because while there might not be code language specifically addressing that exact scenario, there is a requirement to bond metallic pipes. What if an inspector required a jumper in a situation where there was just no basis at all? Yes I would request a code citation. Irrespective of the answer, if the inspector insisted I'd probably just do it as long as it could be accomplished cheaply and quickly - unnecessary but also harmless. The customer does not want to hear about your points of disagreement with the AHJ.

But like Tom points out above, the requirement to bond the water pipes together doesn't really arise from local convention. The pipe is not a continuous length through the water heater, the water heater itself does not incorporate an approved bonding jumper, and unless you install one then you have not guaranteed a low impedance path between the hot water pipes and ground.

I understand that you may feel that in this case there really is no basis in code. A whole lot of people feel otherwise, as I've seen the pipes bonded together at the water heater by dozens of electricians, in houses inspected by dozens of different inspectors in different jurisdictions.

 

[Fred B]

You need to follow your local rules, but not all localities are the same.

If plumbing fixtures cannot be considered as creating a single metallic piping system, do you place jumpers around all shutoff/isolation valves?

The conditional requirement of "Likely to become energized" comes into play. Wouldn't expect any condition that would create a need to make multiple jumpers around a building accross multiple vavles and isolating plumbing components.

 

[jim dungar]

If it's a metallic valve connecting two metal pipes then I wouldn't, because there's no requirement to do so.

You just told me a metallic mixing valve needs to be jumpered.

I really don't care if your localality requires something not explicitedly required by the NEC.

My point is, not every locality in the US requires a cold water to hot water jumper.