Distinguishing between these forms of TNS vs TNCS

[Mizunoid]

In this vid he shows a TNS with a 3 core incomer and the other 3 standard types (TT, TNCS, TNS with sheathing earth connection)

How can we identify the difference between the TNCS and the TNS with a 3 core incomer? Seems to me that both will have an earth coming out from behind the capping on the cut out and therefore make it impossible to tell without pulling the main fuse and taking the cap off.

What you's reckon?

 

[Fleeting]

It is a pretty poor video and it would have helped if he had used the correct incoming cables, concentric for the TN-C-S in particular. Describing the cable for the TN-C-S as having a line and neutral is technically incorrect the 'neutral' is PEN (Protective Earth Neutral).

 

[Mizunoid]

It is a pretty poor video and it would have helped if he had used the correct incoming cables, concentric for the TN-C-S in particular. Describing the cable for the TN-C-S as having a line and neutral is technically incorrect the 'neutral' is PEN (Protective Earth Neutral).

So in a situation like he describes, how do we tell the difference?

 

[Sharpend]

Take some measurements

 

[binky]

not the best video, most of the consumer heads around me look more like A for TN-C-S with a link internally. You also get what looks like TN-C-S heads in many flats where they have run a cable from downstairs on TN-S supply.

 

[Fleeting]

SNE supply heads appear to be TN-C-S but are essentially TN-S.

 

[Mizunoid]

Thanks guys

 

[binky]

Thanks guys

If in doubt you can contact the DNO, who should be able to tell you what you have.