"craigm" wrote in message
...
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.

Yep.

If the load on each phase is relatively balanced, the error may go
unnoticed.

First, how likely is that?


Secondly, I still don't get how the current on the one phase makes a return
path if the neutral is disconnected.


I know it's AC, but what's being described is like disconnecting one of the
leads to a battery. Maybe somebody can better describe the term 'broken
neutral wire'.


If an alternate ground path exists for the neutral things may appear
normal until it fails.

What alternate path? The wire is broken supposedly so there can never be a
return path.

The current in the neutral can be much lower than either of the phases.

How do you reconcile that with Kirchoff's laws?


Craigm