The principle of death by electrocution 15, the principle of death by electrocution

Death from electric shock is often the current passing through the heart, causing the heart to stop, 220V In fact, many people have experienced the feeling of electric shock, but the death is still a minority.

Electric shock on a high-voltage line, as long as the current does not pass through the heart, can usually cause burns to the limbs. Of course, it's over the heart.

As for thunder and lightning, it is often not directly chopped, but standing under a tree, which may produce a step voltage, step voltage: if a person or livestock stands within 8 10 meters of the landing point of the high-voltage power line. An electric shock accident may occur, and this electric shock is called a step voltage electric shock.

When a person is subjected to a stepping voltage, although the current is along the lower body of the person, from the feet through the legs, crotch and then to the feet and the earth to form a pathway, it does not pass through the vital organs of the human body, it seems to be relatively safe. But that's not the case! Because when a person is subjected to a higher stride voltage, his feet will cramp and his body will fall to the ground.

This not only increases the amount of electrical current acting on the body, but also changes the path of the current through the body, making it entirely possible for it to flow through vital organs such as head to hands or feet. Experience has proved that after a person falls to the ground, the electric current continues to act in the body for 2 seconds, and this electric shock will be fatal.

Of course, thunder and lightning are very short-lived, so the power will be long after a person falls to the ground.

Electrocution accidents are caused by the flow of electric current through the human body. People are electrocuted because they are conductors, and when the electric current passes through the body, it destroys the function of the nerves and muscles of the person, resulting in the loss of life. Although there is no positive or negative pole for alternating current, there is a flow of current in a closed circuit of alternating current power supply just like a DC circuit.

Electric man, that is to say, the human body is actually electrocuted by an electric current passing through the human body, resulting in injury or even death of the human body, so the essence of electric shock is that there is an electric current flowing through the human body.

Precautions for the prevention of electric shock accidents:

1. Don't overload electricity. Large-capacity electrical equipment such as air conditioners and ovens should use special lines.

2. Choose qualified electrical appliances, and do not buy and use fake and shoddy electrical appliances, wires, trunking (tubes), switches, plugs, sockets, etc.

3. Do not privately invite unqualified decoration teams and personnel to lay wires and connect electrical equipment, and find qualified units and personnel for installation and repair of electrical appliances.

4. Do a good job of grounding protection for the metal shell of the electrical appliances that are specified to be grounded, do not forget to install the grounding wire for the three-prong socket, and do not change the three-prong plug to a two-prong plug at will.

5. Choose a fuse wire that is suitable for the load of the wire, do not arbitrarily thicken the fuse wire, and it is strictly forbidden to replace the fuse wire with copper wire.

When the amount of electricity enters the body when the amount of electricity enters the body reaches 18 22 milliamperes (mA), it will cause the respiratory muscles to contract at will, resulting in respiratory arrest and severe suffocation; If the current volume exceeds 22 amperes, it can cause the ventricles to fibrillate, causing difficulty in pumping blood and stopping the heart within a few minutes. Therefore, ventricular fibrillation is the leading cause of electrocution death.

1. The electric shock current disturbs the normal bioelectricity of the human body, such as the heart current, which causes the heart to beat and dies 2. The electric shock current paralyzes the nerves, so that the muscle current is disturbed, and the heart beats out of the problem3. A large amount of electric current passes through the human body, emitting a large amount of heat and burning human tissues.

Electric shock or lightning strike is caused by the direct contact of the human body with the power supply, and a certain amount of electric current passes through the human body, resulting in tissue damage, dysfunction and even death. The longer the electric shock, the more serious the electrical damage suffered by the human body, and the lightning strike in nature is also a form of electric shock, whose voltage can be as high as tens of millions of volts, causing extremely strong current electric shock, which is extremely harmful.

Electric shock, there are three cases, in order of strongest to weakest:

1. Line of fire - people - zero line.

2. Line of Fire - Man - Earth For example: enter from the hand and go out through the foot.

3. The zero line is broken. Fire line - electrical equipment - people - earth.

The damage of electric current to the human body can be summarized as the destructive effect caused by the electric current itself and the photothermal effect of electrical energy. The fatal effect of electric shock on people is mainly to cause ventricular fibrillation, which leads to cardiac arrest. On the other hand, it is harmful to the respiratory center of the medulla, causing depression, paralysis and respiratory arrest of the respiratory center.

The photoelectric effect can cause electrical burns.

The degree of harm to the human body of electric shock mainly depends on the size of the current passing through the human body and the length of time it is on. The greater the current intensity, the greater the fatal danger; The longer it lasts, the more likely it is to die.

The minimum value of current that can be perceived by a person is called the perceived current, which is 1 mA for AC and 5 mA for DC; The maximum current that a person can get rid of after an electric shock is called getting rid of the current, which is 10mA for AC and 50mA for DC; The current that is life-threatening in a relatively short period of time is called a lethal current, such as a current of 100mA passing through the human body for 1s, which can be enough to make a person fatal, so the lethal current is 50mA.

In the case of protection against electric shock, the current allowed by the human body can generally be considered as 30mA.

The human body's response to electric currents:

8-10mA hands already have difficulty getting rid of the electrodes, and there is a sharp pain (finger joints). In our stereotype, a voltage of 10,000 volts is more lethal than 100 volts, after all, higher voltages also have more energy. However, this is only partially true, because what really causes a person's death is the electric current that flows through the body.

So, how much electricity can kill us?

Studies have shown that 10 milliamps of current can cause a big shock to the human body, but it is not fatal. When the current approaches 100 milliamps, the person's muscles begin to contract. However, in the special case of an electric current flowing through the heart, just 10 milliamps of current is enough to kill us, because the heart has a lower electrical resistance.

Often, though, it's almost impossible for these tiny currents to pass through and reach the heart.

When the current increases to 1000 milliamps, the human muscles contract and paralyze, making it impossible for us to get rid of the wires. At this time, the heart contracts irregularly, and if no immediate action is taken, the person may die.

When the current increases to 2000 mAh, the person's ** and internal organs will be burned, and the person will lose consciousness. Because the muscle contractions caused by shock are severe, the heart may contract violently, and may even lead to cardiac arrest, leading to death.