John, here in the USA, our neutral and ground (earth) are connected
at the breaker panel. This is connected to the incomming supply ground.

   - Tom

At 03:49 PM 7/25/98 +0800, John Fimognari wrote:
>To the PIC list,
>Sorry Fellas to bore you,
>
>But the power supply problem in the good old US of A interests me. I did
>not know that you guys had a such backward power distribution system.
>Down under in Aus we use a more civilised system. The power is generated
>by delta (triangular) wound alternators. 3 phase is distributed to the
>final point where the transformer is delta wound high tension primary
>and star ( Y ) wound low tension secondary. 415 volts across Phases and
>240 volts to the centre tap. This is the neutral wire which is also
>earthed. (grounded for the USA people). The four wire system is the
>retriculation system used for commercial and domestic consumption.
>
>We use a system called Main Earth - Neutral (MEN). The neutral and earth
>conductors are joined together behind the main switchboard panel and a
>main earth wire is run to the copper water supply and bonded to an
>earthing electrode. In essence every property is also an earthing
>electrode station.
>
>Standards Association Australia states that the neutral potential is to
>be within 5% of the earth potential. ie 12 volts for 240 volts. In
>effect the earth wire is used only as a safety wire. The only time
>current flows through this wire is in a fault condition. It is there to
>save lives.
>
>No wonder you guys in the USA are having problems with your PICS and
>RFI. With a floating neutral system and doddgy earthing system how do
>you get rid of the nasties in your main power supply?
>
>Our 240 volt, 10 amp 3 pin plugs use the same size pins,and yes we have
>the live pin burn out problem as well.
>
>Regards,
>John Fimognari
>Perth,
>Western Australia.
>
>