Neutral/Ground Allowable Current Values

[ghostbuster]

What is the maximum allowable current flow between the electrical panel neutral and the neutral bond wire to the cold water pipe in a suburban residence?What percentage of the total neutral current is allowed to flow on this neutral/ground bond to the copper waterpipe?

 

[brian john]

In a perfect world NONE, in a not so perfect world strive for NONE. To my knowledge there are no standards or specifications.

 

[tom baker]

If its a complete metallic piping path between the house and street main, two adjancent houses connected together, you could see about 20% unbalanced current on the metal water pipes (this is from an American Water Works Assn article about 1980s on this).
An open neutral would have much higher current. It all depends on the resistance of the parallel paths.

 

[ghostbuster]

If its a complete metallic piping path between the house and street main, two adjancent houses connected together, you could see about 20% unbalanced current on the metal water pipes (this is from an American Water Works Assn article about 1980s on this).
An open neutral would have much higher current. It all depends on the resistance of the parallel paths.

Thanks Tom and Brian

I have a situation with 30%-50% of the neutral current returning via the ground.
This equates to up to 15 amps on the ground.This is an aerial feed into the house.
The aerial feed(attached to the whole side of the house) therefore generates a corresponding magnetic field of 15 amps imbalance current into the residence.
The lower part of the residence is used for a high end recording studio.These mag fields get "picked up" by all the recording equipment(lots of hum radiated into the equipment).
The utility is refusing to co-operate.There was no problem until the utility decided to install all new service feeders to these houses.
I suspect the utility has a high impedance system neutral problem with this new wiring in this subdivision.