Incoming supply

[Leonsparky]

Hi, can someone please explain the incoming supplies (TNS, TNC-S etc.)to me. I did study them in installation rules, but struggle to understand it fully.

Thanks

[ACEsterhuizen]

Maybe this will help.

[markthespark]

In your reg manual SANS 10142-1 Annex M gives quite clear indication of the different earthing systems. The best wait to understand them better is to take your manual with you to each site and then visually check the system against the manual. It has helped me a great deal!Soon you will easily be able to identify the system you are inspecting.

[AndyD]

If you're unsure by looking at the supply then perform a PEFC and a PSCC test on the supply at origin and if the two results are identical it's almost certainly a TN-C-S arrangement.