I have often heard that the grounded distribution
system was developed from a safety viewpoint.
If, in fact, it is not safer, what happened?
Was the safety analysis done incorrectly?
Was the grounded system developed for some
Today we can detect faults with GFCI devices.
These work independently of whether the system is
grounded or not by comparing the current in the
two wires to the device, and breaking the circuit
if the two currents are not equal-opposite.
Prior to GFCI availability, faults were detected
when a live wire contacted the properly grounded
metal case of the appliance, and thereby caused
the fuse or circuit breaker to blow. It seems to
me this was the main method of detecting single
faults as they occurred as John has suggested we
Michael D. Edmiston, Ph.D.
Professor of Chemistry and Physics
Bluffton, OH 45817