Polarity testing supply

[Mikegh]

I'm probably missing something obvious here but if the polarity is reversed upstream of the cutout


How are they getting 230v between N-E ?

Surely they're still linked at the cutout ?

 

[Rockingit]

OK, so there's two other principal earthing systems in the UK that aren't TN-C-S, and consider if they're actually getting 230v or just 'a voltage'. How does that help your thinking?

 

[Mikegh]

I get it for the other 2 systems

But in the example shown if the supply is reversed at the cutout and you're connecting it to the MET

 

[Rockingit]

Draw it out