Earthing and neutral help

[davesparks]

ok but my point is, lets say your measuring N-E at a CU, technically your measuring N-N are you not?

If the CU is at the origin of a TNCS installation then yes you pretty much are, assuming the tails are the right way round in the cutout.

The thing with safe isolation is that you test everything as its not worth risking your life on assumptions

 

[gazdkw82]

Absolutely. It just dawned on me that essential at a cu point on tncs N-E is essentially N-N. but like you say, always check everything

 

[Ian1981]

Absolutely. It just dawned on me that essential at a cu point on tncs N-E is essentially N-N. but like you say, always check everything

Think about when your doing an IR test as well.
If you don't isolate the neutral at the main switch you essentially will get 0.00 Mohms with a neutral to earth insulation resistance test