Authors : Dwarka Prasad, Ashwani Kumar Sharma and H.C. Sharma
Abstract: People often assume that any grounded object can be safely touched. A low substation ground resistance is not in itself a guarantee of safety. There is no simple relation between the resistance of the ground system as a whole and the maximum shock current to which a person might be exposed. Therefore, a substation of relatively low ground resistance may be dangerous while another substation with very high resistance may be safe or can be made safe by careful design. The severity of electric shock to humans from low voltage (60 Hz) low source impedance systems is dependent on many variables. These factors include the body impedance, current magnitude and duration, voltage and frequency of the circuit and the current path traversed in the body. Several researchers have investigated safe voltage and current limits that humans can withstand. As a result, thresholds have been established of the body's response to 60 Hz alternating current of a few milliamperes in low voltage systems. This study will briefly explain the causes of electric shock and their effects on human body.
Dwarka Prasad, Ashwani Kumar Sharma and H.C. Sharma, 2010. Electric Shock and Human Body. International Journal of Electrical and Power Engineering, 4: 177-181.