Water Pipe

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john8791

Member
Location
Iowa, US
Occupation
Electrical Engineer
I have a question regarding cold water pipe as a grounding electrode in an older (1960's) house. When I moved in (1996), the only grounding electrode was the cold water pipe. I installed supplemental ground rods and under direction from our city inspector bonded both the ground rods and water pipe to the service entrance ground bar.

I will be selling the house soon and went back looking at things. As I understand it, NEC 250.52 does not allow the cold water pipe to be part of the grounding electrode beyond 5' where it enters the premises. The inspector had me bond it to a cold water pipe near the service entrance, but the service entrance is more like 25' from where the cold water pipe enters the house. Question is: Is there a length restriction on how long a bare conductor may run to comply with the 5' rule? 250.64 discusses whether protection is needed or not but doesn't seem to have a length restriction. Also, previous owner(s) had a receptacle's equipment ground connected to a cold water pipe. I believe this was acceptable prior to 1993 code? Would the buyer's inspector mark this as a defect?

Thanks
 

RonPecinaJr

Senior Member
Location
Rahway, NJ
The metal underground water pipe connection needs to be connected not less than 5' from where it enters the building. Why an inspector would tell you to make the connection anywhere else is beyond me. As for the receptacle, I would either remove it or install GFCI device.
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I have a question regarding cold water pipe as a grounding electrode in an older (1960's) house. When I moved in (1996), the only grounding electrode was the cold water pipe. I installed supplemental ground rods and under direction from our city inspector bonded both the ground rods and water pipe to the service entrance ground bar.

I will be selling the house soon and went back looking at things. As I understand it, NEC 250.52 does not allow the cold water pipe to be part of the grounding electrode beyond 5' where it enters the premises. The inspector had me bond it to a cold water pipe near the service entrance, but the service entrance is more like 25' from where the cold water pipe enters the house. Question is: Is there a length restriction on how long a bare conductor may run to comply with the 5' rule? 250.64 discusses whether protection is needed or not but doesn't seem to have a length restriction. Also, previous owner(s) had a receptacle's equipment ground connected to a cold water pipe. I believe this was acceptable prior to 1993 code? Would the buyer's inspector mark this as a defect?

Thanks

You are correct. The grounding electrode must be within 5' of where the metal water pipe enters the building. The reason for this is assuring that the premise does not loose the GEC when the plumbers installs a piece of plastic piping in the line.

In terms of the receptacle I would read 250.130(C). Basically if the ground wire from an existing 2 wire non grounding circuit is run to a point on the grounding electrode (5 ' from where the water pipe enters) then you are compliant.
 

iwire

Moderator
Staff member
Location
Massachusetts
You are correct. The grounding electrode must be within 5' of where the metal water pipe enters the building.

I am sure Dennis meant the grounding electrode conductor must be connected to the water line within 5' of the water line entering the home.

The actual electrodes can be anywhere.
 

JohnJ0906

Senior Member
Location
Baltimore, MD
. Question is: Is there a length restriction on how long a bare conductor may run to comply with the 5' rule? 250.64 discusses whether protection is needed or not but doesn't seem to have a length restriction.

There is no length restriction.

Sometimes the service equipment is on the opposite side of the building from the water entrance, and the GEC is over 100' long (or even much longer, depending on the building size)
 

Dennis Alwon

Moderator
Staff member
Location
Chapel Hill, NC
Occupation
Retired Electrical Contractor
I am sure Dennis meant the grounding electrode conductor must be connected to the water line within 5' of the water line entering the home.

The actual electrodes can be anywhere.

That is what I meant- thanks but for the water pipe I thought the electrode stops after 5 feet and then it is just water pipe. After 5' the water pipe is no longer an electrode suitable for compliance 250.50. I know you know this but your statement that the electrode can be anywhere is misleading to me.
 

john8791

Member
Location
Iowa, US
Occupation
Electrical Engineer
Thanks for the good info guys. How about this for a (easy) solution:

1.) Re-run the bare conductor to within 5' of the cold water entrance into the house.

2.) Because the receptacle in question is the logical place for the TV, stereo, etc. to be plugged in, an equipment ground is really needed for TVSS. I could unhook the existing connection to the water pipe and connect with a split bolt connector to the new bare conductor I am running. As that would be part of the GEC I believe that would be in compliance with 250.130(C). Right?
 

ecox

Member
Section 250-81 was revised in the 1993 Code to prohibit the use of that portion of the interior metal water piping system that extends more than 5 ft beyond the point of entrance into the building to interconnect grounding electrodes and the the grounding electrode conductor.

Prior to that, the practice of bonding to the waterline at the closest point to the service equipment was acceptable.

If I read your question correctly, this work was done prior to the 1993 Code change, so the connection being more than 5 feet from the point where the water line enters the building would not be a violation.

However if and when the panel is updated or replaced, this connection would have to be in compliance with the current code.

As to a presale inspector gigging you with this, I would expect that they would. You could argue the point with them, providing that you have evidence that the installation was prior 1993.
 

john8791

Member
Location
Iowa, US
Occupation
Electrical Engineer
If I read your question correctly, this work was done prior to the 1993 Code change, so the connection being more than 5 feet from the point where the water line enters the building would not be a violation.

The work I did was done in 1996, again the city inspector told me to do it that way. The outlet grounded to the pipe was pre-existing.
 

acrwc10

Master Code Professional
Location
CA
Occupation
Building inspector
The work I did was done in 1996, again the city inspector told me to do it that way. The outlet grounded to the pipe was pre-existing.

Just because the work was done in 96 does not mean you where under the 96 code cycle at that time. The fact that you did it the way the inspector instructed you to tells me that you were under an earlier code, if it is something that makes you lose sleep change it, if not leave it.
 

john8791

Member
Location
Iowa, US
Occupation
Electrical Engineer
I think I will fix it. Does anyone think the idea in my previous post (restated below) is objectionable?

Because the receptacle in question is the logical place for the TV, stereo, etc. to be plugged in, an equipment ground is really needed for TVSS. I could unhook the existing connection to the water pipe and connect with a split bolt connector to the new bare conductor I am running. As that would be part of the GEC I believe that would be in compliance with 250.130(C). Right?
 

RonPecinaJr

Senior Member
Location
Rahway, NJ
I was just reading 250.130 (C) and what you propose seems to meet the requirement of the section. However, if you're going to go through the trouble of running an EGC all the way back to the panel, why not just run a whole new cable from the receptacle back to the panel?
 

hurk27

Senior Member
The made EGC if ran separately from the circuit conductors, it would be in violation of 300.3(B)

as far as the GEC it would probably be protected by article 9 section 21 of the Constitution of the United States, which reads that "No post facto law shall ever be written" which is the bases of all grandfather laws.

But insurance and loan company's can still require things to be brought up to code as they can refuse their service as a freedom of their choice, but an inspector does not have this power since he is there to enforce the law.

Edited to add:
Also as a note SPD's have no value in the grounding conductor, there is no load to protect? the load is connected to the hot and neutral. many good quality SPD's don't even have TVSS connected to the grounding conductor, just another marketing ploy
 
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e57

Senior Member
The made EGC if ran separately from the circuit conductors, it would be in violation of 300.3(B)

as far as the GEC it would probably be protected by article 9 section 21 of the Constitution of the United States, which reads that "No post facto law shall ever be written" which is the bases of all grandfather laws.

Much like the current 5' rule for GEC/ECG connection to the electrode - running seperate from the circuit was not always so either - may even had changed at the same time?

FYI my water connection is the furthest point of my water system - I sleep fine... (Done in the 80's I think?)
 

M. D.

Senior Member
The made EGC if ran separately from the circuit conductors, it would be in violation of 300.3(B).....

What about 406.3(D)(1) in conjunction with 250.130(c) ?? It seems they recognize the EGC will be separately run.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
The metal underground water pipe connection needs to be connected not less than 5' from where it enters the building. Why an inspector would tell you to make the connection anywhere else is beyond me. As for the receptacle, I would either remove it or install GFCI device.

Because once he put in the ground rods he was no longer using the coldwater as a ground and was simply bonding it, and you can bond it anywhere in the system as long as it's accessible. Plus it wasn't required to be within the first 5' in 1960.
 

Twoskinsoneman

Senior Member
Location
West Virginia, USA NEC: 2020
Occupation
Facility Senior Electrician
What about 406.3(D)(1) in conjunction with 250.130(c) ?? It seems they recognize the EGC will be separately run.

Great job M.D. I think 250.130(C) certainly allows you to connect to any accessible part of the GEC. I guess the thought is that it is better to have an EGC with higher impedance (not with the BC) than none at all.
 

cpal

Senior Member
Location
MA
I
The inspector had me bond it to a cold water pipe near the service entrance, but the service entrance is more like 25' from where the cold water pipe enters the house.

Thanks


Sorry if I'm missing something but I do not see where you insure the underground pipe is metal??

If it is I agree with group that the GEC must be attached within 5 feet of the water pipes entrance to the structure. If it is a non metallic water service which converts to copper within the structure you may bond the interior piping at any convenient location.
 

M. D.

Senior Member
Great job M.D. I think 250.130(C) certainly allows you to connect to any accessible part of the GEC. I guess the thought is that it is better to have an EGC with higher impedance (not with the BC) than none at all.


I'm pretty sure here in Mass they have deleted 250.130(c) :rolleyes:
 
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