trekkie76, in reality earthing the grounded circuit conductor serves no purpose for normal operation or fault clearing for low voltage systems (600 or less).
The main purpose for earthing or groundind the system is to provide a discharge path for lightning, and clear high voltage faults in the event of accidental contact between primary and secondary.
To a lessor extent earthing is used to stabilize sytem voltages, short out capacitive coupling to ground Paul refenced too, and signal reference point.
Look at it this way planes, trains, automobiles, boats, etc are not earthed. The only place earth is used to clear faults and carry load current is high voltage applications.
[This message has been edited by dereckbc (edited 10-30-2004).]
