Bonding ground rod to water pipe to nuetral bus

[BrianJohn]

And if the studies are true Copper in concrete should be one of the best electrodes.

For those of you with copper incoming water pipes, living in a neighbor with copper to all houses and common utility transformers (feeding more than one house). If you have an amp clamp measure the current on the Grounding electrode Conductor.

 

[Lakee911]

And if the studies are true Copper in concrete should be one of the best electrodes.

Isn't that an Ufer ground?

For those of you with copper incoming water pipes, living in a neighbor with copper to all houses and common utility transformers (feeding more than one house). If you have an amp clamp measure the current on the Grounding electrode Conductor.

Measure the current on my grounding electrode conductor between my panel and the pipe? Why?

 

[Sponsor]

 

[JWelectric]

Isn't that an Ufer ground?

Nope it is a concrete encased electrode but a lot call it a Ufer

Measure the current on my grounding electrode conductor between my panel and the pipe? Why?

Your service could be carrying the unblanced current from your neighbor's service.

 

[Lakee911]

What if it is carrying the unbalance current from the neighbor? What can/should I do about it?

 

[JWelectric]

What if it is carrying the unbalance current from the neighbor? What can/should I do about it?

Call the power company is all you can do

 

[BrianJohn]

It is possible for the water piping system between houses to carry current as this path is in parallel with the neutral conductor (as noted above), this current can be yours, your neighbor or neighbors. If the current is significant it could be the result of neutral connections issues in one or more of of the homes.

In my opinion, and this is controversial, I would have a plumber install a dielectric coupling at the street side of the metallic water piping. This avoids the current sharing issue and minimizes EMF. The NEC will address this issue sooner or later.

A lot of hoopla is made over grounding electrodes for residences, and while important this subject probably gains more attention and concern that is worth the effort.

For instance the NEC wants a water pipe, CCE, ect. But if you have to utilize rod electrodes all you need is to prove 25 ohms or less with a single rod, if the readings are above 25 ohms say 1000 ohms they only require a second rod, which might result in 998 ohms.

 

[Master Plumber Mark]

Have not heard back from Bob....

Thank you for everyones answers....

I have been courious and wondering about this for
quite a long time because in our area I run into that problem all the time...

Whenever a person has burnt through 3-5 water heaters in less than 10 years,.....even with dialectric unions...
their is usually somethign bad wrong....

I have one old man who we have changed out 5 electric water heaters in less than 10 years.....It has a PRV valve,
and we have literally done everything to the system....

called in an electrician but they seem to "know it all "
and claim that everything is fine.....

the last one I installed with the new flex rubber lines to
insulate the heater....

I am waiting to hear back from him some day soon. when #5 finally blows .....


and I am going to personally put another ground rod into his basement floor and jumper everything to that rod
--------------------------------------------------------------------

their is usually always some contributeing factor to the situation....

either the water softener has broken the ground to the
plumbing system, or their is simply no decent ground at all left serveing the home.
or a plastic water line was run to the home in the first place and their is
literally no back up water ground.....

whats going on outside the home is another issue.......

When trouble shooting these special ones, it just seems
the only answer is to add an extra ground-rod to the home...
possibly in the garage floor and or crawl space and jumper the plumbing system over to new grounds..

and I usually get scoffed at from their electrician. for suggesting this approach.........

 

[BrianJohn]

MPM:

1st few residential electricians are going to 'KNOW IT ALL", nothing against them but you just can't learn "It all" doing residential.

2nd there are quite a few studies (check WSSC's web page) on AC currents and effects on water piping. To date there has be no data connection the two. DC current yes, AC no.

3rd Grounding for some reason has taken on mystical properties in the electrical field. Engineers, electricians and other concerned parties have tried all kinds of HOO-DOO VOO-DOO to conquer, tame, direct control GROUNDS. When in fact there is only one thing to remember about grounding, in residential distribution it is a 4th conductor and in 3 phase commercial work it is the 4th conductor in a (most) delta*1 systems and a 5th conductor in wye systems.

*1 Yes I know about 3 phase 4 wire Delta and then there is 2 phase 5 wire, but I am talking most common Distribution systems.

JW:

Why would you contact the local utility?

 

[JWelectric]

and I am going to personally put another ground rod into his basement floor and jumper everything to that rod

Why is this world would you do all this for? When you drive that rod then you have to bond that rod you just drove back to the grounding electrode system of the service so all you have done is make the grounding electrode system for the service bigger.

The problem of the metal water pipe that is used as an electrode carrying current will have nothing to do with the elements of a water heater nor will it cause them to burn out.

Then there is always the chance of being charged with installing electrical systems with out a license.

The water heater is already connect to earth through the equipment grounding conductor ran with the branch circuit supplying the unit so this rod will accomplish nothing except extra work and cost on your part.

JW: Why would you contact the local utility?

The only way that any noticeable current will flow on a metal underground pipe from one building to another will be an open neutral on the utility supply side. There will be a little current but nothing that will cause any problems.

In cases such as mobile home parks where the homes are real close together, current will flow through the earth its self from one electrode system to another. The installation of a nonmetallic fitting in an underground metal pipe system will reduce the amount of current flow will in no way stop the flow.

 

[Lakee911]

The water heater is already connect to earth through the equipment grounding conductor ran with the branch circuit supplying the unit so this rod will accomplish nothing except extra work and cost on your part.

Only if it's electric.

The only way that any noticeable current will flow on a metal underground pipe from one building to another will be an open neutral on the utility supply side. There will be a little current but nothing that will cause any problems.

If the houses are closes together and bonded well, if they have an open nuetral it could flow on their ground to the pipe, from the pipe to your panel and through your nuetral, no?

Jason

 

[Lakee911]

http://ecmweb.com/grounding/electric_shocking_truth_grounding/

 

[Master Plumber Mark]

extra grounding

LAKE911...thank you......that link is very informative.

quite a bit of it is over my head,... but I have seen sparks
before when I have cut out a water heater jump across the pipes..

I have seen sparks before when I have disconnected a prv valve
in a basement by the water meter.....with the whole house
going dark when it came apart....
I was lucky not to have been lit up on that one...

I am going to have to sit back and read that article slowly



no I probably wont personally install another ground in the home...

although it baffles me why we have a good handful of customers that literally eat through water heaters like they are candy..... all with the same symptoms


the best advice given...

is to call the local utility company and let them come \
out and see what is gong on out in the street..

 

[Nate R]

WOW. GREAT link!

I have always treated a ground rod or ground to water pipe connection as harmless, never really as live. Never again.

 

[Lakee911]

That opened my eyes too. I've always thought that they were harmless too. I'm going to test mine when I have the chance this weekend.

Jason

 

[JWelectric]

The water heater is already connect to earth through the equipment grounding conductor ran with the branch circuit supplying the unit so this rod will accomplish nothing except extra work and cost on your part.

Only if it's electric.

Well what did the man say?

I have one old man who we have changed out 5 electric water heaters in less than 10 years.....

The only way that any noticeable current will flow on a metal underground pipe from one building to another will be an open neutral on the utility supply side. There will be a little current but nothing that will cause any problems.

If the houses are closes together and bonded well, if they have an open nuetral it could flow on their ground to the pipe, from the pipe to your panel and through your nuetral, no? Jason

and for this type of problem do what this man said.

Call the power company is all you can do

Don’t need no degree to figure all this out unless you are an employee of the utility company in which case you can just fix it your self.
By the way it is spelled n-e-u-t-r-a-l not

open nuetral …..your nuetral, no? Jason

 

[BrianJohn]

The only way that any noticeable current will flow on a metal underground pipe from one building to another will be an open neutral on the utility supply side. There will be a little current but nothing that will cause any problems.

No the water pipe is in parallel with the neutral and significant current can flow on the pipe. depending on the load distribution between the lines, obviously.

 

[Master Plumber Mark]

the link died

lake911 that link has died....

perhaps itwill come alive later today,

can you re-post it or

could you tell me the site where you found it?


Had my coffe ready and was sitting down for a good read
this morning.....
Now I guess i will do the dishes instead..




thank you

MPM

 

[Nate R]

It will take a while to load, but the Internet Archives aka the Wayback Machine is a wonderful tool!

http://web.archive.org/web/20070717.../grounding/electric_shocking_truth_grounding/

 

[JWelectric]

No the water pipe is in parallel with the neutral and significant current can flow on the pipe. depending on the load distribution between the lines, obviously.

This is very true but taking into consideration the difference of resistance between the conductor that is connected to the service and the metal in the water pipe that travels a greater distance and the different devices connected to the metal water pipe such as water meters I think that any current flow on the metal water pipe would be nil unless there was a problem with the connections between the conductors and the utility.

The earth is also in parallel with the service conductors but it also has a high resistance meaning that the current carried between the earth rods is nil.

 

[BrianJohn]

I can only speak for the services (I generally do commercial work) I have been contracted to check, with no utility issues 5-10 amps was the average amperage I saw, a lot of variables play into this, distance between houses, load distribution, size of water pipe, number of houses on the transformer and water utility connections, ect...