When a faulty piece of equipment without an equipment ground wire is plugged into an electrical outlet not containing a ground wire, the case of the instrument will become hot.
An individual touching the hot case (point A) will receive a shock because he or she is standing on the earth (point B) and completes the circuit. The current (dashed line) will flow from the instrument through the individual touching the hot case.
An individual touching the hot case (point A) will receive a shock because he or she is standing on the earth (point B) and completes the circuit. The current (dashed line) will flow from the instrument through the individual touching the hot case.