I have a number of questions regarding the
wiring systems used in the US.
1) Do the commercial/industrial installations
use a 3-phase system, similar to the 230/400V
MEN system here in New Zealand?.
2)How is an installation earthed in the US?,
wether this be a domestic,commercial or
industrial type installation.
3)Why are internal circuits in US houses,
run in metallic flexible?.
4)Why do US socket outlets not have in-built
switches?.
