On Tuesday, 7 May 2019 15:55:42 UTC+1, John Rumm wrote:
I can't immediately think of one... more to the point I am not even sure
you could buy a new VO RCD these days anyway?


I'm not sure you can either, but the Wiring Regs committee hope that someone will make them fairly soon.

The answer seems to be electric vehicle charging points in single-phase PEN installation.

722.411.4.1(iii)

The main earth terminal is connected to a an earth electrode and again in the event of a break of the incoming PEN conductor the voltage between the main earth terminal and the earth does not exceed 70 V.

Owain