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How many of you believe it is normal to have current on a metallic water pipe used as a grounding electrode?
 

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is there an electric water heater involved? a bad element can cause strange things, including people getting shocked from touching almost any metal
 

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I agree some current is normal however you should not have 3 amps. Normally I find less than an amp.
 

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2-3

2-3 volts every time at ground. Best engenered job. Im betting have done 500 +communication towers. halo grounding. Grounding connects to 3-4-5 volts because of grounding.
 

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If you are in an area with a metal underground water piping system that is common to a number of buildings in the same area, the metal underground water pipe is a parallel path for the grounded conductor current. In many cases the resistance of the path via the water pipe is very low. It is not uncommon to have 20% or more of the grounded conductor current flowing on the water pipe in these cases.

Often the path via the water pipe is good enough that you will not even notice if the service drop grounded conductor is open...that is unless you see that there is no current on the neutral conductor and a lot of current on the GEC that connects to the water pipe.

The other place you often find grounded conductor current is on the TV cable shield, but usually not a lot because the resistance of this parallel path is much greater than the resistance of the service grounded conductor.
 

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If you are in an area with a metal underground water piping system that is common to a number of buildings in the same area, the metal underground water pipe is a parallel path for the grounded conductor current. In many cases the resistance of the path via the water pipe is very low. It is not uncommon to have 20% or more of the grounded conductor current flowing on the water pipe in these cases.

Often the path via the water pipe is good enough that you will not even notice if the service drop grounded conductor is open...that is unless you see that there is no current on the neutral conductor and a lot of current on the GEC that connects to the water pipe.

The other place you often find grounded conductor current is on the TV cable shield, but usually not a lot because the resistance of this parallel path is much greater than the resistance of the service grounded conductor.
Because of the conditions that Don has stated above, and we have a lot of the same common water pipe systems here, I always tell the plumbers I work around to make sure to put a jumper cable across any buried main water pipes they are intending to cut thru.
 

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If you are in an area with a metal underground water piping system that is common to a number of buildings in the same area, the metal underground water pipe is a parallel path for the grounded conductor current. In many cases the resistance of the path via the water pipe is very low. It is not uncommon to have 20% or more of the grounded conductor current flowing on the water pipe in these cases.

Often the path via the water pipe is good enough that you will not even notice if the service drop grounded conductor is open...that is unless you see that there is no current on the neutral conductor and a lot of current on the GEC that connects to the water pipe.

The other place you often find grounded conductor current is on the TV cable shield, but usually not a lot because the resistance of this parallel path is much greater than the resistance of the service grounded conductor.

Excellent explanation! :thumbup::)
 

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And don't forget kids! The current on the gec might not be leaving your structure, it might be entering the gec from somebody else's lost neutral down the street. So your good grounding job, might be not so good given the amount of ''somewhat lost on it's way home'' current.
 

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Not necessarily there are several other reasons for ground current.
Correct, an open neutral or loose neutral would cause excessive ground current, but as Don said a normal amount is always present. The degree vs normal conditions will determine if it is abnormal or normal. That amount depends on the resistance of the neutral (service drop length and size) the resistance of the water pipe and the amount of load on the neutral. Both vary in the real world.

Current takes all paths rather than the path of least resistance.

In theory, if the neutral and water pipe have the same resistance current would be equal, though come real world its generally not the case. Real world the resistance of the neutral is never a perfect zero ohms, and not all water pipes are over 100 ohms, (ones interconnecting homes might be as low as 1/2 an ohm) so measurable current flow does occur.
 

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One of my fav apprentice stumpers is to take a GEC , and tap it lightly to an H20 pipe so it produces a spark....:whistling2:

Doesn't make me a bad man to mess with their little heads, does it? :jester:~CS~:laughing:
 

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And don't forget kids! The current on the gec might not be leaving your structure, it might be entering the gec from somebody else's lost neutral down the street. So your good grounding job, might be not so good given the amount of ''somewhat lost on it's way home'' current.
That is exactly what was happening at my house. I did not notice my ground current until I changed my service and saw the spark, with the main off. I would check it at times. I checked it again after I saw the electric company at a neighbors house. It went away.
 

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And don't forget kids! The current on the gec might not be leaving your structure, it might be entering the gec from somebody else's lost neutral down the street. So your good grounding job, might be not so good given the amount of ''somewhat lost on it's way home'' current.
This!

Tap your ground wire on your water pipe and see which one of your neighbors porch lights keeps flashing brighter and softer.
 

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Had a customer recently who had electromagnetic field's in the house but only in one spot on the floor. I know we had some current coming in on the water line so I told her to get the plumber to dig up by the meter and replace the first 2 feet or so with plastic. This way I still had an electrode.

That helped but she still has a bit coming in somewhere. We disconnected the entire house, pulled the meter, and there was still some current on the neutral which was still connected. When we disconnected the neutral it went away. There isn't much I can do about that.

P.S. What I said about 3 amps was an arbitrary load...Just making a point that there should be some but not alot of current
 
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