What is a dangerous current for a person? Deadly and dangerous current values

An electric shock is a shock to a person, after which a shock can occur - a severe reaction of the body to a strong irritant, which is an electric current. It should be understood that any current is dangerous to human life. The article also answers the question of what current and voltage are dangerous to humans.

Electric Shock Outcome

Depending on the situation, the outcome of the shock can be varied. If a person received a strong electric shock, he may have problems with blood circulation and breathing. In severe situations, heart fibrillation may begin - the heart muscle begins to twitch chaotically. Since the heart actually stops working, the flow of blood stops. If first aid is not provided, the person may die in a timely manner.

Most often, electric shocks are observed at the time of electric shock to people with a power of up to 1000 V. Burns can occur when exposed to current from 1 A or higher. This happens mainly if, when working with a current of more than 1000 V, a person does not comply with the elementary safety rules. The current-carrying part is at a fairly close distance to the human body, a spark discharge arises between them, which leads to severe burns.

If a person accidentally received a spark discharge, the current at the time of connection with the body heats the tissue to 60 °. This leads to coagulation of the protein, and a burn is formed on the affected area. Burns caused by electric shock are quite difficult to cure.

Signs of burns from electric shock

There is such a thing as electrical tags. These are dead skin areas of a yellowish color that look like corns. If the current penetrates deep into the skin, the body tissue will die over time.

Signs of an electric burn:

• the skin in the area of ​​impact turned red;
• burns with the formation of blisters began to appear at the site of the focus;
• the tissues at the point of impact were charred;
• pieces of metal could get into the skin when the clothes were straightened.

Most dangerous if an electric shock occurred in the area:

• temples;
• backs;
• hands
• lower legs;
• nape;
• neck.

Classification of electric current by degree of exposure to humans

Electric current varies in its degree of exposure to humans. He can be:

• palpable;
• non-releasing;
• fibrillation.

Sensible is an electric current, upon impact of which a person feels obvious irritation. You can feel the shock of current at 0.6 mA.

Non-releasing - an electric current that causes involuntary jerky movements of the limbs that touch bare wires.

An alternating current, passing through the cells of the human body, gives impulses at which a person has an adherence effect.

Fibrillation current on impact causes problems with the heart system. At this point, a person may die from cardiac arrest.

Dangerous current

Depending on the situation, a voltage of different sizes can pass through the human body, which means that the effect of the lesion can be diverse. You need to know that a current that is dangerous for a person has a current strength of more than 15 mA, at which a person is not able to escape without assistance. A current of 50 mA can cause severe damage to health, and at 100 mA when exposed to 1-2 seconds is considered deadly and usually causes cardiac arrest.

The most dangerous current for humans is alternating, the frequency of which is more than 50-500 Hz. If its value is about 9 mA, a person is able to free himself from the source of damage (wire). You must understand that for life and health of people is a danger and direct current, which can be released only if it does not exceed 20-25 mA.

What alternating current is dangerous for humans?

People who regularly work with electronic and electrical devices know what alternating current and direct current are. But not all of them possess information, which one is more dangerous for humans.

It should be understood that electricity is a danger to people, many factors influence this. Such as:

• how long the contact lasted;
• the paths along which the current passed through the body;
• what power was the blow;
• resistance of the human body.

AC is considered dangerous to humans. Causes:

• Direct current will have the same effect on the human body if it is 3 times larger than alternating current. This happens because alternating current stimulates the nerves much more and stimulates the muscles and heart.
• Electric shock death usually occurs as a result of cardiac arrest. The risk of death is most often present when working with alternating current.
• The resistance provided by the human body is higher than direct current, and the higher the frequency, the lower the resistance.

From this it becomes clear that alternating current is much more dangerous for human life than direct current.

What direct current is dangerous for humans

Danger to humans is both alternating and direct current. The only thing is that the variable is 35 times more dangerous than the constant. It is worth knowing that DC power of 50 mA is considered safe, while for alternating current this mark is only 10 mA. But the main thing is that the danger of any current depends precisely on its intensity.

It is considered:

• at voltage up to 400 V alternating current is more dangerous;
• if the voltage is 500 V, the effect of the current is the same;
• at voltages above 500 V, direct current is more dangerous.

Alternating current hits intermittently, while direct current flows continuously. When struck by alternating current, there is a chance to break away from the source of damage. It should be understood that the danger is not only the type of current that struck a person, but also what area was affected. The most dangerous path of current through the heart, brain, lungs.

Direct current is dangerous for humans, as electric shocks can result in burns or breathing problems.

What organs are affected by electricity?

How much a person’s body was struck at the moment of electric shock depends on which path the current went through. In practice, there are several options by which current can pass through the body:

• If a person takes a bare wire under voltage with both hands. This path is referred to as hand - hand and passes between the hands, affecting the respiratory system and the heart.
• When a person is standing on the ground, he touches the exposed wire with his hand. The path is called the arm - legs, the current penetrates through the internal organs of the breath and heart.
• A worker stands on the ground, in the area of ​​faulty grounding. A discharge of current is received by the legs. The path of the current is called foot - foot.
• When a person accidentally touched the head of the conductive part. The path may be referred to as head - arm, head - legs.
• The most dangerous ways in which current can pass through the body are those in which the most important systems for humans are involved.
  

How dangerous is electric shock?

If an electric shock occurs at a voltage of 500 V, a person will feel pain in the place of touch, in the joints, burns will appear. And there is also a high probability that the breath will stop or the heartbeat will stop.

It should be understood that at a voltage of 500 V, the difference between both types of currents is virtually absent. There is a non-linear relationship between the current that passes through the human body and the voltage. Therefore, with increasing voltage, the current strength increases.

In any case, the strength of an electric shock depends only on the individual conditions under which a person is caught in the power grid.