On Feb 16, 6:04*pm, Brian wrote:
If on a 220 single phase circuit the neutral and ground wires attach to the same buss bar in the
panel, why are they both needed ????

Thanks
Brian

Already answered, but...

The prime directive is that the neutral ALWAYS carries a load and the
ground NEVER carries a load, the ground just travels around to bond
everything providing a return path that becomes available as a safety
ground. If you allow the ground wire to carry a load, the circuit
will "work" but be unsafely and ungrounded. This is the reason you
never re-bond the ground in a subpanel, (it would make the ground
carry load between the panels), you just ground the subpanel and only
bond the neutral to the bus in the subpanel without re-bonding the
ground wire.