wrong size grounding electrode to water pipe installed. Danger?

[green2012]

There is a 200 amp underground service that was installed using #6 to the cold water pipe. The grounding electrode runs 100 feet from the cold water, through the panel, and is terminated outside in the meter socket ground bar. The suplimental ground going to the 2 ground rods is terminated side by side to the electrode wire from cold water. Does this pose a danger? Should the 100 feet of #6 be replaced? What are the potential dangers if any?

 

[Dennis Alwon]

Yes the #6 should be replaced with a #4 to get the most protection from the water pipe as an electrode. In reality I don't think it is a big issue esp. at 100' away. I assume the water line is metallic underground for more than 10' coming into the house.

Someone else may be able to give a more scientific answer.

 

[102 Inspector]

Agree that # 4 required for grounding electrode basedon Tab. 250.66 (2008 Ed.). The distance seems excessive however if connected within 5 feet of entering the structure, that is where it should be. Our area does not aallow a connection in the meter base and therefore connects to the assembly at the main disconnect.

 

[green2012]

Connection is required at meter (meter has disconect), and its 100 feet because the water meter enters at the other end of the building. It is grounded on the street side of the water meter about 3 feet after entering the building from utility. Yea from the sound of it we are going to go ahead and repull the #4. Too bad the inspector didnt catch it.

 

[Strathead]

Connection is required at meter (meter has disconect), and its 100 feet because the water meter enters at the other end of the building. It is grounded on the street side of the water meter about 3 feet after entering the building from utility. Yea from the sound of it we are going to go ahead and repull the #4. Too bad the inspector didnt catch it.

But did you see Dennis' question. To put it more straight, it is unlikely if the house was built in modern times (post 1990) that the water pipe has 10 feet of metal in direct contract with the earth, and if that is the case then a #6 is fine because it is just a bodn to ensure all metal parts that may become energized are bonded.

 

[tom baker]

But did you see Dennis' question. To put it more straight, it is unlikely if the house was built in modern times (post 1990) that the water pipe has 10 feet of metal in direct contract with the earth, and if that is the case then a #6 is fine because it is just a bodn to ensure all metal parts that may become energized are bonded.

What size does the code require?

 

[Strathead]

What size does the code require?

Off the top of my head, I believe that the code requires all metal parts... to be bonded with a size large enough to carry the fault current. In CA, they used to make us jump a #6 from the cold to the hot to the gas at the water heater, but I contended that, the gas, for example, was bondedby the ground in the same romex that fed an igniter (the source that could energize the gas line) and therefor already bonded to code. However, path of least resistance, I never argued this, but merely discussed it. I live in Florida now. NO such requirement.

 

[tom baker]

Take a look at 250.104. For the purposes of this forum, I respectfully suggest we go beyond it should be fine, and answers off the top of our heads. Others come to this site looking for the code answer.

 

[Dennis Alwon]

Connection is required at meter (meter has disconect), and its 100 feet because the water meter enters at the other end of the building. It is grounded on the street side of the water meter about 3 feet after entering the building from utility. Yea from the sound of it we are going to go ahead and repull the #4. Too bad the inspector didnt catch it.

If the meter is in the house then I would jump across the meter.

250.53(D)(1) Continuity. Continuity of the grounding path or the bonding connection to interior piping shall not rely on water meters or filtering devices and similar equipment.

 

[Strathead]

Take a look at 250.104. For the purposes of this forum, I respectfully suggest we go beyond it should be fine, and answers off the top of our heads. Others come to this site looking for the code answer.

I should not have answered. My memory was flawed by and thinking of 250.104 (B) and not realizing that the water pipe and any other metal piping was dealt with separately. Now this this section, I say holy cow! What a ridiculous section. I did not realize it was there. It kind of makes 250.53 (D) redundant. The only difference being the within 5 feet of entrance clause. On top of that, since it states water piping system(s), it would appear that you need to run a 250.66 jumper from the hot to the cold water, and and 250.66 jumper if a pipe section is replaced with a non conductive material, or a dielectric junction is installed.

Show of hands. How commercial structures have you seen that have a jumper to every hot water piping system isolated for the codl water? I have never seen one, so what am I misinterpreting in this code section?

 

[jxofaltrds]

If the meter is in the house then I would jump across the meter.

Film it for us!