Confusion between grounding and bonding is common. For example, many people wrongly believe that standing on (or being connected to) on a ground rod prevents them from being shocked. You can verify this is wrong, by drawing out the circuit and doing some calculations.
Assume some reasonable value for the earth resistance and use the standard 100 ohm value for the resistance of your body. By applying Kirchoff’s Law, you’ll see that electricity does not follow the path of least resistance; current flows in both paths (through your body and through the earth). Use whatever system voltage you’re working with, and you can calculate how much current flows through your body when you’re grounded.
Now try this with a zero resistance shunt (bonding jumper), and you find zero amps flowing through your 100 ohm body. A metallic bond isn’t zero resistance, but it’s a very low resistance that’s much lower than earth resistance.
Always keep Kirchoff’s Law in mind when someone talks about a “safety ground.”
