Main Earthing Conductor and Earthing System question.

[Risteard]

Are you guys seriously saying you don’t know the typical Ze values for TN-S and TN-C-S?

A typical MAXIMUM value is not the same thing as a typical value.

A TN-S reading can be extremely low if near the transformer.

 

[Deleted member 26818]

A typical MAXIMUM value is not the same thing as a typical value.

A TN-S reading can be extremely low if near the transformer.

And?

 

[Risteard]

Are you guys seriously saying you don’t know the typical Ze values for TN-S and TN-C-S?

A typical MAXIMUM value is not the same thing as a typical value.

And?

And it disproves your earlier remarks?

 

[Deleted member 26818]

A typical MAXIMUM value is not the same thing as a typical value.

And it disproves your earlier remarks?

Disproves nothing.
It’s a statement which has no value.
There are no typical maximum values.
There is either a maximum or a typical value.

 

[Risteard]

Disproves nothing.
It’s a statement which has no value.
There are no typical maximum values.
There is either a maximum or a typical value.

They are typical maximum values as the DNOs are not compelled to remain within those values.

 

[Deleted member 26818]

They are typical maximum values as the DNOs are not compelled to remain within those values.

No the maximum value would be infinity.
The maximum value allowed would be a value determined by a person or persons.
A typical value would be a value that a person or persons would expect to be found.

 

[Ian1981]

I’ve measured various values for ze for both tns and tncs, in a career as an electrician that has upto now lasted 19 years, what I can conclude is that there is NO typical value at all.
I’ve measured 0.10 ohms for tncs, measured 0.15 ohms for tns, I’ve also measured 0.30 ohms for tns, and countless other values.

 

[Nigel]

If I had to take a guess I would guess a 0.21 reading is more likely to be a TN-S than a PME.

 

[westward10]

You guess a lot of earthing systems

 

[Nigel]

You guess a lot of earthing systems

No, but as I said “if I had to”

 

[Wilko]

Perhaps a measurement may be helpful? (He suggests quietly, while putting on his tin hat...)

 

[Baddegg]

Post 3 wilko....0.21

 

[Deleted member 26818]

I’ve measured various values for ze for both tns and tncs, in a career as an electrician that has upto now lasted 19 years, what I can conclude is that there is NO typical value at all.
I’ve measured 0.10 ohms for tncs, measured 0.15 ohms for tns, I’ve also measured 0.30 ohms for tns, and countless other values.

Seriously?
19 years and you don’t know the standard or typical values for Ze?

 

[Deleted member 26818]

If I had to take a guess I would guess a 0.21 reading is more likely to be a TN-S than a PME.

PME conditions can apply to TN-S.

 

[Wilko]

Post 3 wilko....0.21

I was thinking to compare this Ze with line to neutral impedance.