FDR wrote:
"w_tom" wrote in message
...

The investigator was a personal friend who we stumbled upon
as he was returning from the exploded house. He immediately
explained what had happened - the broken neutral wire inside
transformer and no building earth ground. It was one of
those, "Of course. I never realized that could happen."
moments. As it would when one is familiar with 'how and why'
buildings and utilities are earthed.


I'm sorry, but if the neutral broke then there could be no return current
for the single phase legs. Power would go out at the house.



Only if all the devices are one a single phase.

With an open neutral there is still 240 volts available at the
structure. If the load on each phase is relatively balanced, the error
may go unnoticed. If an alternate ground path exists for the neutral
things may appear normal until it fails. The current in the neutral can
be much lower than either of the phases.

Craigm