Electric currents flowing through the human body can have hazardous consequences.
Every electrical installation is therefore required to incorporate protective
measures to prevent hazardous currents from flowing through the human body.
Components being energized during normal operation must be insulated, covered,
sheathed or arranged to prevent them from being touched if this could result in hazardous
currents flowing through the body. This protective measure is termed ‘protection
against direct shock hazard’ (new term: ‘protection against electrical shock hazard
under normal conditions’). Moreover, it goes without saying, of course, that a
hazard must not be caused either by current flowing through the body if, as the
result of a fault, e.g. a faulty insulation, the voltage is transferred to the metal enclosure
(body of a piece of electrical equipment). This protection against hazards that, in the
event of a fault, can result from touching bodies or extraneous conductive components,
is termed ‘protection against indirect shock hazard’ (new term: ‘protection against
electrical shock hazard under fault conditions’).