David writes:
AIUI in the USA for residential 120/240V single-phase three-wire service
drops, electrical utilities either run all three phases along the
distribution line or they run two phases. Running one phase and a neutral
instead of two phases would reduce the power by the square root of 3
Here in rural Wisconsin the 7200V distribution line leaves the
substation as three phases and a grounded neutral. This eventually
branches out into three single phase lines consisting of a phase and a
grounded neutral. The pole pigs are connected phase to neutral.