In shock situations, the voltage across the human
body in contact with the system is calculated. The
grounding system designed should not allow any
voltage to build across the human body and the
ground above this calculated voltage. It is found to
be a function of the weight of the person. For
instance a person weighing 70kg can tolerate more
voltage than a person of 50kg. Also the tolerable
voltage across hand to hand or hand to foot (Fig 15)
is found to be greater than the tolerable voltage
across leg to leg. We can write the tolerable voltage