tn-c-s and tn-s

[jeffelectric]

Earth joined to neutral at head and wire to sheaf on incoming ?

 

[RyanCheetham]

DIY PME attempt? Call DNO to clarify earthing arrangements

 

[GLENNSPARK]

what do you want to know...?
Which is which Jeff?

 

[trev]

Someone been at the Rowntrees Randoms again?

 

[GLENNSPARK]

TN-C-S:
a neutral-earth block used to link the 2.....some service heads will have an external connection point for the main earthing conductor......but one cannot assume its linked internally to the neutral....as the link is removable.....depends on whether or not PME is available in the area....MAX. Ze: 0.35

TN-S:
using the outer sheath of a paper-lead cable as the earth fault path....or the earthings of a split concentric.....a constant pressure spring is used to make the connection to the sheething for the main earthing conductor....although bonding clamps to BS951 are common....MAX. Ze: 0.8

 

[Darkwood]

I believe the OP is saying the incoming has both an earth on the sheath or whatever a sheaf is... as well as an earth into the cutout N/E connection...... Its probably been converted tns to tncs so your answer is tncs....usually a pme sticker has been attached. The armour still requires earthing whichever set up it is but this isn't down to our responsibility.

 

[GLENNSPARK]

I believe the OP is saying the incoming has both an earth on the sheath or whatever a sheaf is... as well as an earth into the cutout N/E connection...... Its probably been converted tns to tncs so your answer is tncs....usually a pme sticker has been attached. The armour still requires earthing whichever set up it is but this isn't down to our responsibility.

well then its either a DNO upgrade.....due to deteriation of the TN-S arrangements....
or theres been maybe some recent work carried out...and someone couldn`t get a Ze....so decided to PME it....

 

[jeffelectric]

Yes it was tn-s and has been changed to tn-c-s, but looks like both. thanks everyone