On 16/04/2021 16:47, Andy Burns wrote:
NY wrote:

I'm used to seeing three-wire (three phases) overhead mains wiring from
poles along a street.
But I'm mystified about five-wire mains.

TN-S system (not TN-C-S)

L1, L2, L3, N, PE

See photo here (it's not good, and you'll have to zoom in a bit)
https://ibb.co/7Cs99M2

A temporary 500kW generator was required recently to cover for some work
on a nearby substation. It was connected up to the overhead lines
nearby. There were five cables from the generator to the lines. The
upper three were connected to, I expect, the three live phases (they are
the upper three cables with the yellow insulated connectors). There were
two further connectors (uninsulated?). They are the lower two in the
photo, and both appear to be connected to the fourth line( below the
three live phases), which I assume is the neutral. Would those two
connections be neutral and earth from the generator to make a common
neutral/earth connection?

--

Jeff