power on water line

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I'm stumped,

A home inspector tested the water line entering a townhouse and found 1.7 amps. I also found 1+ amps on the water line. I thought that for sure the foreign amperage was coming from the service, but I disconnected the ground from the water line there was still current on the water pipe. I turned off the main breaker and it was still there. Also with the power off I was getting the same reading on the neutral, with the ground off. Has anyone had a similar experience?

Thanx Alex
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
Is it a true townhouse design? If it has seperate water meters then I'm a little stumped too, but if it has a single meter or all of the meters are tied together with metalic pipe, then the proble could be else where and not in that paticular unit. Also check to see if there is a dielectric fitting at the water service, if there is, then the problem has to be somewhere in that unit.
 

brian john

Senior Member
Location
Leesburg, VA
Most likely common utility transformers and common utility metallic water line as noted.

BUT if these are back to back town homes (common party wall which is usually the definition of a town home) I have found crossed circuits between two homes the ground current was from crossed neutrals in the kitchen, they crossed the garbage disposals circuits in a duplex box that also had the SA circuit.

Is this a calibrated meter?

Were you holding it properly 90 degrees to pipe, with pipe dead center (improves accuracy)

Check the neutrals in the panel, service lateral as well as branch circuits.
Is the current on the GEC? As well as the water pipe?
Is the current on the neutral ground bond?
Is this an end unit or middle unit?

You are not stumped, you just have not checked everything yet!
 

nakulak

Senior Member
don't forget that the current can be coming into the house on the water line from neighbor's defective ckt/loose neutral/ground fault/poco stray current.
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
Most likely common utility transformers and common utility metallic water line as noted.

BUT if these are back to back town homes (common party wall which is usually the definition of a town home) I have found crossed circuits between two homes the ground current was from crossed neutrals in the kitchen, they crossed the garbage disposals circuits in a duplex box that also had the SA circuit.

Is this a calibrated meter?

Were you holding it properly 90 degrees to pipe, with pipe dead center (improves accuracy)

Check the neutrals in the panel, service lateral as well as branch circuits.
Is the current on the GEC? As well as the water pipe?
Is the current on the neutral ground bond?
Is this an end unit or middle unit?

You are not stumped, you just have not checked everything yet!

While I could see how that could happen, I would have never thought to look for that. Good catch.:grin:

Another thing is that the cold water may not be bonded at all. It may only be bonded at the main service to the nearest CW pipe and if they are all individual water services the might not have got jumped.
 

JohnJ0906

Senior Member
Location
Baltimore, MD
I'm stumped,

A home inspector tested the water line entering a townhouse and found 1.7 amps. I also found 1+ amps on the water line. I thought that for sure the foreign amperage was coming from the service, but I disconnected the ground from the water line there was still current on the water pipe. I turned off the main breaker and it was still there. Also with the power off I was getting the same reading on the neutral, with the ground off. Has anyone had a similar experience?

Thanx Alex

don't forget that the current can be coming into the house on the water line from neighbor's defective ckt/loose neutral/ground fault/poco stray current.

I agree with nakulak. Also, although you lifted the ground from the water pipe, there is probably another connection through one or more EGCs of circuits such as dishwasher, disposeall, water heater, etc. So there would still be a path for current even with the main GEC to the water lifted.
 

cschmid

Senior Member
What possessed him to clamp an amp meter around a water line?

I was wondering the same thing? yet the earth is a good conductor with the amount of services that are stablize in small areas. such as city blocks loaded with residential housing units. so I can see a small amount of current on the common water main.
 

brian john

Senior Member
Location
Leesburg, VA
I was wondering the same thing? yet the earth is a good conductor with the amount of services that are stablize in small areas. such as city blocks loaded with residential housing units. so I can see a small amount of current on the common water main.

Some seminar he took?
 

cschmid

Senior Member
kind of like the home inspector took a 1 hour class and now he is an expert on getting people all worked up over a non existant problem. all tough if there is some hazardous voltage associated with this then it could be an issue.
 

brian john

Senior Member
Location
Leesburg, VA
kind of like the home inspector took a 1 hour class and now he is an expert on getting people all worked up over a non existant problem. all tough if there is some hazardous voltage associated with this then it could be an issue.

I do not think we can fault him fopr looking into different things.
 

220/221

Senior Member
Location
AZ
I bet he found 1.7 volts from the water pipe to a screwdrive stuck in the ground.

You can read 1.7 volts on a cereal box.

Well, maybe not a cereal box but you know what I'm saying.
 
At least twice in the last year it has been in local papers where condo owners were being billed for a neighbors electricity due to meter assignment problems. (Two reported, how many not yet found out?)

If metering can be crossed, so can other factors.

Not direct to the question, but related to home inspectors, in one community which had only pvc water service to homes, a home inspector flagged a water meter with pvc coming from the street and feeding to the house main cutoff because it had no bonding jumper.

It still is important to identify the source.

I was checking out a tripped breaker in a major restaurant chain location and found potential from neutral to ground at a fixture.

One of the seven panels had a bad neutral connection and it was so red hot all the insulation was melting. I temporarily tightened the connection and as soon as poosible replaced the connection and have a contract to inspect panels annually.
 

brian john

Senior Member
Location
Leesburg, VA
At least twice in the last year it has been in local papers where condo owners were being billed for a neighbors electricity due to meter assignment problems. (Two reported, how many not yet found out?)

If metering can be crossed, so can other factors.[/quote}

This is a poor analogy, Cheap radios and unit B and unit D sound similar.

Not direct to the question, but related to home inspectors, in one community which had only pvc water service to homes, a home inspector flagged a water meter with pvc coming from the street and feeding to the house main cutoff because it had no bonding jumper.

Now that is funny
 

cschmid

Senior Member
Not direct to the question, but related to home inspectors, in one community which had only pvc water service to homes, a home inspector flagged a water meter with pvc coming from the street and feeding to the house main cutoff because it had no bonding jumper.


Now that is the perfect example of why HI's should not be allowed to do inspections all they do is get people upset and normally for nothing.
 
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