Dodgy earthing?

[jonno1805]

Hi everyone,

I've just bought my first house and whilst doing DIY I have being trying to figure out what type of earthing the consumer unit has. I have looked at all of the diagrams on the Wiki but I want to describe it in this post as it doesn't seem to be any of them... The supply to the main fuse comes in in a copper pipe containing just the live and neutral wires, while an earth wire from the cu is bonded to this pipe. There is also as another earth wire going from the cu which runs to the gas main.

Any help would be appreciated,

Jonno1805

 

[sparkwright]

TNS.

 

[sparkwright]

Are you certain this is where the main feed comes in?

 

[jonno1805]

Are you certain this is where the main feed comes in?

Well this goes into a box with 'electricity service phone' written on it, and the wires from this go in to the meter.

 

[sparkwright]

Sounds like TNS then. The 'copper pipe' is the sheath of the cable, and this copper sheath provides the earth as well.

Gas and water and other such services should be bonded, to the main earth terminal, which can be inside or outside the consumer unit.

 

[Lectrician]

Certainly sounds like an MI / Pyro DNO submain, and appears TN-s, although it really depends what's at the other end. It could be PME there, and this is where it becomes contentious when deciding if its TN-S or TN-C-S.