electrics into house

[john24uk]

Hi all again guys, i just wondered if anyone has pics are diagrams on where and how the cables are run from the grid to the house, where they all connected to! Hope it makes sense

 

[ban-all-sheds]

Try the National Grid website and those of some DNOs?

 

[john24uk]

Ok will do thanks BAS, its not for anywork am doing just intersted where it goes to underground and so on

 

[Guitarguy]

Right, drawn a little diagram of how it works. It shows how the power gets from the national grid (the gert big metal pylons) to your house.

 

[bongos]

Right, drawn a little diagram of how it works. It shows how the power gets from the national grid (the gert big metal pylons) to your house.

Am I right in thinking that in a TN system the neutral is supplied from the distribution substation or does it go further back than that?

With TT is the neutral supplied from the pole mounted transformer?

 

[mfarrow]

Am I right in thinking that in a TN system the neutral is supplied from the distribution substation or does it go further back than that?

Yes that's correct, and the neutral is tied to the earth mat of the substation at that point.

With TT is the neutral supplied from the pole mounted transformer?

Yes, but note that the neutral may not be at true earth potential, hence double pole switching is required for isolation for maintenance.

 

[bongos]

With TT is the neutral supplied from the pole mounted transformer?

Yes, but note that the neutral may not be at true earth potential, hence double pole switching is required for isolation for maintenance.

I was aware that the neutral may not be at 'true earth' potential when connected to a pole mounted transformer (TT installs) but why is this? Is the transformer itself not earthed at this point also?

 

[Guitarguy]

With TT is the neutral supplied from the pole mounted transformer?

Yes, but note that the neutral may not be at true earth potential, hence double pole switching is required for isolation for maintenance.

I was aware that the neutral may not be at 'true earth' potential when connected to a pole mounted transformer (TT installs) but why is this? Is the transformer itself not earthed at this point also?

The transformer is earthed on the HV and LV side. However, there could still be a small amount of voltage present in the event of a fault somewhere on the LV network