Earth at the separation point (TN-C-S) of the DNO...

Carlos Arruda · Apr 25, 2015

Hi all.

It seems there has been quite some different opinions in my classroom as to who should really change the earth cable in the incoming position where the 100A fuse is, in domestic installations.

Can any qualified electrician, change the earth cable at the DNO side? Say for example on an old installation that needs to be brought to the 21st century, will one have to call the DNO to have this upgraded?

Pic bellow.

https://www.dropbox.com/s/mc892iqcm065n6q/PME1.jpg?dl=0

Many thanks in advance.

Regards,
Albert

telectrix · Apr 25, 2015

it's usual to have to pull the fuse to remove the cover from the Earth terminal in ones like your pic. some come with the terminal exposed, which is easy. where the fuse needs to be removed, by rights you should call DNO. ( cough, cough).

Pete999 · Apr 25, 2015

Simple answer is the DNO as the cut out would be a sealed unit, wouldn't it?

davesparks · Apr 25, 2015

It depends on the cutout, some of them have an accessible earth terminal which you can connect to yourself, others require the DNO to do the connection.