Good call C-H,
While the NZ block system here could be called a Ring Main,it is a 3 phase one, fused at every "take-off" point at single phase or 3 phases, depending upon the load.
As I've said before here, the real use for Ring Mains in NZ are for Caravan Parks.
With Neutral-Screened cables and an RCD at each socket on the system and an earth electrode at every 2nd or third box, (depending on the size of the park).
Things are a Faultsman's worst nightmare, drunken tourists with no power.
Worst ones are Kiwi's from just down the bloody road, that wanted to try out their new campervan. [Linked Image]