[A27Hull]

Thanks to you both Zmix and Mike,

Its beginning to make sense. I'm a beginning electronics tech with a nasty habit of asking "why" all the time. I guess thats why I'm doing engineering as well. I have a lifetimes worth of knowledge to learn still.

I made a block diagram to simplify the situation. It would seem that in a three prong system, shorting either neutral or hot to the chassis by any means (whether circuit ground or fault) would create a current loop between the earth ground and that neutral or hot wire. Anything touching the chassis would become a impedance mismatch to earth, causing a voltage drop across that object and a current flow of some amount. In a sense the object creates an additional parallel path to earth.

If this is true, why connect the circuit ground to chassis/earth at all?