Suppose normal residential main breaker panel (not subpanel) is wired correctly except the neutral bar is not bonded to ground. Assume a 15A breaker in the panel powers an exterior light with a metal casing. The metal casing is connected to the ground wire. Suppose the hot wire to the light comes in contact with the metal casing (remember the ground and neutral are not bonded in the breaker panel). Will current flow through the breaker? How much current will flow? Would there be enough current to trip the breaker? Suppose a person in bare feet on moist ground touches the metal casing. Is the person going to be electrocuted or shocked?
Thanks for all the time and effort by each of you to answer my question. It is not an exam question. The breaker would not be GFCI. In the US, a main panel always has ground bonded to neutral; in a subpanel the ground must never be bonded with neutral. Perhaps a simpler scenario would answer my question. Suppose the single hot wire from my 15A breaker (not GFCI breaker) is connected via a switch to a copper ground rod in the soil. (Again, the breaker panel is wired improperly since ground and neutral not bonded together.) I have no idea what the resistance would be in the soil to complete the circuit back to the transformer. If you close the switch would there be enough current to trip the breaker?