Current present in earthing conductor

[Jabbajaws]

My friend and l are testing a new installtion. Can anybody tell me why, when we are testing the main earthing conductor with an earth leakage meter, are we detecting an average Current of 8-9mA which is constantly increasing and decreasing from a minimum of 0 A to a maximum of 11mA.

The Installation that is under test is swtiched off at the Main Switch, along with all of the breakers

There is 0A flowing through the main tails, yet it flows in the earthing conductor.

We want to know why, if anyone has any thoughts on the matter...


Your, JaBBaJawS...

 

[zupos40]

My friend and l are testing a new installtion. Can anybody tell me why, when we are testing the main earthing conductor with an earth leakage meter, are we detecting an average Current of 8-9mA which is constantly increasing and decreasing from a minimum of 0 A to a maximum of 11mA.

The Installation that is under test is swtiched off at the Main Switch, along with all of the breakers

There is 0A flowing through the main tails, yet it flows in the earthing conductor.

We want to know why, if anyone has any thoughts on the matter...


Your, JaBBaJawS...

Possibly TNCS supply, in that case neutral and earth are connected together at the supply and you could be reading current flowing along the neutral in the road.

Another thought it could also be because of induced EMF from parallel live conductors.

 

[Darkwood]

Tncs systems can generate eddie currents around the earthing system between local buildings hence the need for larger earths

 

[Jabbajaws]

Thanks, Guys,

That has helped me loads. It is a TN-C-S we are working on, and it does sound logical what youre saying...

 

[acvc]

Getting away from the topic, but just out of interest, what would the effect be on Ze if there is such an eddie current?

 

[Des 56]

Getting away from the topic, but just out of interest, what would the effect be on Ze if there is such an eddie current?

As far as I am aware,with local eddy currents
Once a potential difference is applied then the eddy curents wont exist

 

[acvc]

Is that between any two conductors in the system, or just the neutral+earth?