CONDITIONS electric shock to persons.
Effect of electrical current to the person affected when you turn your body into an electrical circuit. The latter circumstance may occur as a result of contact with live parts of electrical installations, and in case of contact with the metal no current-carrying their part, find themselves under stress because of damage to electrical insulation.
Study the causes of industrial electric accidents shows that about 60% of the accidents occurred due to direct contact with live parts to open, normally energized (accidental touch or as a result of the power supply to the area. Where people work) and more than 25% to the metal parts of equipment, facilities, normally not under stress.
Touches of possible bipolar (phase-phase) and single-pole (phase-earth) is the most dangerous circuit bipolar touch. When you touch the bipolar current flowing through the human body on one of the most dangerous routes to the body (hand-arm), will depend on the applied voltage to the body equal to the line voltage network, as well as the resistance of the human body, i.e. energized, but due to violations of the electrical insulation found themselves under stress, can also be dangerous because of the earth fault current passes through the human body.
When you touch ungrounded housing equipment having electrical insulation breach, the person is again included in the circuit is open circuit. In the networks above 1000 due to the large capacitance between the wires and ground the protective role of insulation is completely lost. In other words, under such stress for the person is equally dangerous to touch the wire network as an isolated and earthed-neutral, and to network with isolated neutral the closure phase on the ground around the site of closure may have dangerous to people voltage. In a network with grounded neutral in this case, the risk of defeat can be eliminated because of the rapid off the damaged section suitably protected.
Electric shock may not only under specified conditions, but the transition to high-voltage network of the lower.