Bonding/Grounding copper water lines

jminer99er

Member
Location
Sacramento, CA
Only thing I can think is dc series resistance from neutral? It was the end of the pole line. There is no egc. L1, L2 and neutral, gec #6 enclosure to a ground rod.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
It seems to me that if L1 shorts to N, moving N and EGC in the direction of the L1 voltage, it would necessarily raise the L2 to N voltage.
I do not yet understand your argument that the L2 to neutral voltage will decrease. Unless you are assuming that both the L1and L2 voltage from the transformer will decrease because of a short on L1 only.
Yes, it is my opinion that a short will pull all of the voltages coming out of the transformer down.
 

rcmoon

Member
Location
Florida
Its surprising to me of some of the replys and theories as to what happened to me which was I stated in my original post. What part of "I'm 100% certain that one of my service drop hot conductors came in contact with my bare neutral conductor at the service drop" do you not comprehend?

Maybe this will enlighten some of you. Here is a link to Mike Holt, http://www.mikeholt.com/swimmingpoolbonding.php If you play this video #3 on pools from the 13 minute point on you'll see Mike Holt actually answers my concern about connecting the service ground to my copper water pipes.

I will leave my copper water pipes disconnected from my service ground wire since it seems its a safer thing to do.
 

user 100

Senior Member
Location
texas
Its surprising to me of some of the replys and theories as to what happened to me which was I stated in my original post. What part of "I'm 100% certain that one of my service drop hot conductors came in contact with my bare neutral conductor at the service drop" do you not comprehend?

Maybe this will enlighten some of you. Here is a link to Mike Holt, http://www.mikeholt.com/swimmingpoolbonding.php If you play this video #3 on pools from the 13 minute point on you'll see Mike Holt actually answers my concern about connecting the service ground to my copper water pipes.

I will leave my copper water pipes disconnected from my service ground wire since it seems its a safer thing to do.
Then you might as well get rid of anything with an egc bonded to a metal surface, because they would be energized too in your scenario- those bonded copper pipes are basically connected to the source (transformer) the same way that grounded refrigerator/stove/freezer case is thru the egc. Freezer case lights up in garage during this event, you touch it while standing on slab barefoot, you get bit.

Let's say this happened the way it did and the tranny fuse didn't open or some rarity occured, you know what? Thats a poco problem, not an excuse to do away w/ bonding. The professionals who responded here "comprehended" pretty well, and explained at great length/detail why this was highly unlikely.

I agree w/ the above that you are free to do as you wish, but that you are mistaken, and are making a mistake.
 

rcmoon

Member
Location
Florida
Then you might as well get rid of anything with an egc bonded to a metal surface, because they would be energized too in your scenario- those bonded copper pipes are basically connected to the source (transformer) the same way that grounded refrigerator/stove/freezer case is thru the egc. Freezer case lights up in garage during this event, you touch it while standing on slab barefoot, you get bit.

Let's say this happened the way it did and the tranny fuse didn't open or some rarity occured, you know what? Thats a poco problem, not an excuse to do away w/ bonding. The professionals who responded here "comprehended" pretty well, and explained at great length/detail why this was highly unlikely.

I agree w/ the above that you are free to do as you wish, but that you are mistaken, and are making a mistake.
I agree with your first two paragraphs. But at least I have eliminated one way of my family getting killed or shocked. Theres no other way my copper water lines can get energized once I disconnected them from the service ground. So I have one less shock hazard to be concerned with.
 

roger

Moderator
Staff member
Location
Fl
Occupation
Electrician
Theres no other way my copper water lines can get energized once I disconnected them from the service ground. So I have one less shock hazard to be concerned with.
Is your W/H gas? How pure is your water?

Roger
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
I agree with your first two paragraphs. But at least I have eliminated one way of my family getting killed or shocked. Theres no other way my copper water lines can get energized once I disconnected them from the service ground. So I have one less shock hazard to be concerned with.
If you are on a metallic underground water piping system that is common to other building, the other buildings can have faults that will energize your water pipes.

In my opinion given all of the types of faults that occur in or around a dwelling unit, unbonding the water piping system, increases the shock hazard.
 

user 100

Senior Member
Location
texas
If you are on a metallic underground water piping system that is common to other building, the other buildings can have faults that will energize your water pipes.

In my opinion given all of the types of faults that occur in or around a dwelling unit, unbonding the water piping system, increases the shock hazard.

Op could insert a piece of plastic into the main to prevent this, or talk the neighbors into unbonding their pipes from the common system (this one is not gonna happen:happyno:). Doing that could cause problems later due to a compromised neutral- there would be no back up. And he wouldn't be lowering risk of shock appreciably or if at all if someone gets caught between something live and the pipes. He might be missing common/have poor intersystem bonding to the tranny already b/c if he lost the neutral, that pipe should have picked up the current.
 
Last edited:

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
It seems to me that if L1 shorts to N, moving N and EGC in the direction of the L1 voltage, it would necessarily raise the L2 to N voltage.
I do not yet understand your argument that the L2 to neutral voltage will decrease. Unless you are assuming that both the L1and L2 voltage from the transformer will decrease because of a short on L1 only.
Proper terminology used improperly can certainly cause confusion.

The way a center tapped transformer is physically constructed impacts what can happen.
If L1 is connected/shorted to N the voltage between them approaches zero. The N-L2 voltage is unchanged, as long as the N remains connected to the transformer. Therefore the L1-L2 voltage goes down from its nominal level. The current flowing on the N conductor will depend on if the measurement is made upstream or down stream from the L1-N fault. Downstream of the faulted connection, the N will only carry normal current levels.

However if the N connection is broken all sorts of different things can happen. However the OP says this was not the case, so my contribution is done.
 

ActionDave

Moderator
Staff member
Location
Durango, CO, 10 h 20 min without traffic from wing
Occupation
wire pulling grunt
I agree with your first two paragraphs. But at least I have eliminated one way of my family getting killed or shocked. Theres no other way my copper water lines can get energized once I disconnected them from the service ground. So I have one less shock hazard to be concerned with.
Not really. All you have done is make it a little harder to clear a fault it the water line becomes energized.
 

iwire

Moderator
Staff member
Location
Massachusetts
Not really. All you have done is make it a little harder to clear a fault it the water line becomes energized.

Yes, and you might never know it's energized till you stand outside the home turning your outside water on or off.



rcmoon, you might try to remember these rules where developed over a 100 years by 1,000s of qualified people. Now you come along and think you know better. Do you not see an issue there?
 

rcmoon

Member
Location
Florida
Yes, and you might never know it's energized till you stand outside the home turning your outside water on or off.



rcmoon, you might try to remember these rules where developed over a 100 years by 1,000s of qualified people. Now you come along and think you know better. Do you not see an issue there?
Did you watch the video from Mike Holt that I referenced in a prior post? He clearly says its not a good idea to ground your plumbing pipes.
 

iwire

Moderator
Staff member
Location
Massachusetts
Did you watch the video from Mike Holt that I referenced in a prior post? He clearly says its not a good idea to ground your plumbing pipes.
Your link takes me to four videos totaling hours .... so no.

Can you tell me which video and roughly far far into it?
 

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
Retired Electrical Engineer - Power Systems
Did you watch the video from Mike Holt that I referenced in a prior post? He clearly says its not a good idea to ground your plumbing pipes.
You are mistaken in what you think the video is saying.
At your reference point in the video, Mike is specifically talking about some inspectors requiring the bonding of individual metallic plumbing components which are otherwise connected only by non-metallic piping.
This is not the same discussion as the N-G bond required for a complete metallic piping systems.
 

user 100

Senior Member
Location
texas
In my prior post it says #3 at the 13 minute point and beyond. Mike actually says its a terrible idea to ground your plumbing pipes and etc.
No, he does not. What Jim Dungar says above is true.

Back to your original post and scenario, I would think a poco fuse may even actually open faster if there was a common bonded water metallic system between neighbors due to there being multiple good paths to the source for the fault current, if there was a short betwixt the h and n on the drop as you claimed- but you would want to eliminate that backup/ redundancy?

Even a few amps is normally measured on common metal water systems due to the neutrals connected to, and being in parallel w/, the metal piping systems, but you don't feel tingles do you? :)

Want to entirely eliminate any hazards? Then get your house replumbed w/ plastic.
 
Last edited:
Top