High Ze

[Welsh_sparky_21]

Question for you. Was testing a flat, it’s a massive house that’s been split into flats. All meters are in cupboard at front of the house. 10mm twin and earth from the fuse for this flat goes into a big isolator, from that isolator a 2 core 16mm armour supplies this flat, who’s responsible for that armour? The DNO or me?

 

[westward10]

After the meter it is not the DNO responsibility.

 

[UNG]

The thread is titled High Ze and the question is what is the problem.

From your description it is hard to envisage exactly what you have, how long is the 10mm² t&e run and how long is the swa run?
Anything after the suppliers metering belongs to you

 

[Welsh_sparky_21]

The thread is titled High Ze and the question is what is the problem.

From your description it is hard to envisage exactly what you have, how long is the 10mm² t&e run and how long is the swa run?
Anything after the suppliers metering belongs to you

Sorry. Bit at the end didn’t post, was getting a Ze of 0.41 for a TNS system which I know is fine but still seems to be a high reading for a Ze, the 10mm T+e is about half a meter and the swa is roughly 10-15m hard to tell can’t really see what route they’ve taken

 

[timhoward]

If you are concerned about the SWA you need the earth loop measurement both ends of it, so at the Isolator and at the consumer unit, and that will tell you if you have reason to be concerned or not.

Unless there was something else suggesting an issue I wouldn't generally be worrying about a TNS Ze of 0.41 ohms, you might be a good distance from substation after all.