Which earthing system is this, TN-S or TN-CS?

ringer · Mar 13, 2012

Came across this today. Initially thought it was TN-S then spotted the PME sticker and notice. If the green/yellow earthing conductor coming from the supply head to the MET is joined to the neutral inside the head, why have they left the original braid from the incoming sheath still attached to the MET? Is it perhaps because they would rather leave it in place than risk damage by removing it? And isn't the earthing conductor usually taken out the top of the supply head, or does it not matter? Is this still classed as TN-S even though it is (according to the notices) PME?

[ElectriciansForums.net] Which earthing system is this, TN-S or TN-CS?

MKMK · Mar 13, 2012

This is TN-C-S

Paul.M · Mar 13, 2012

The DNO do this when upgrading to a PME but the local dis station isn't ready at the time so they leave it for us lot to sort out.

Disconnect the PME earth at the earth term and do a Ze on the braid, and then vice versa to compare readings and also check they are connected.

Silly Sausage · Mar 13, 2012

The braid has been left connected because the cable sheath is an Exposed Conductive Part?

I like the old sticker, only £2 fine for chopping the seals!