On Nov 23, 6:40*pm, "Phil Allison" wrote:
"kreed"

From what I can gather, pretty much every home in the US has a 120v -
0 - 120v system where the 2x 120v's are 180 degrees out of phase.
Between the 2 phases 240v is available for stoves, air conditioners
etc.

In Australia, most separate homes have a straight single phase 240v
supply, its not common for there to be 2,3 separate phases to the
average house. *Therefore the scenario Sylvia mentions is less likely
to occur, as not many people have this multi phase system.

The exception here could be blocks of flats, if the main neutral to
the building fails, and there isn't a good earth, the imbalance could
be a risk.

** There is always a good "earth" *available *- courtesy of the water mains
in the street being linked to neutral at every premises.

..... *Phil

All new construction [last 30 years] around here uses iron mains with
rubber sealed joints and plastic service pipe into all homes, so there
is NO bond from the house to the main. The Gas main is plastic, as are
the service drops. So, the only earth connection is the rather 'iffy'
pair of 8' ground rods usually in the rain shadow of the roof
overhang.

Neil S.