Dangerous tension. What tension is considered dangerous for human life?

Often, electric shock occurs due to the violation of the rules for working with high voltage or the person does not know how to properly handle electrical appliances. In any case, the main cause is human carelessness.

What danger for a person is a high voltage?

Even the smallest impact on the human body of electric current can cause damage. It is necessary to take into account not only the fact, what will be the power of electric shock, but also how much it will act on the body. Dangerous stress for a person can be even minimal, as much depends on the body itself. The current can not be seen with your own eyes, determined by sound or by smell, the effect begins when the person touches it.

How can the current affect the human body?

The electric current can instantly spread when it touches the entire body. In order for him to pass through the body, he needs a place of "entry", and then the current, passing through the entire body, has an irritating effect on him. For example, the effect of current on the human body is divided into several types:

1. Thermal, when a burn is obtained.
2. Mechanical, when there is a rupture of soft tissues.
3. The chemical is directly electrolysis itself.

Due to electric shock, a person can involuntarily contract muscles, paralyzes breathing and stops the heart.

What stress is dangerous for humans?

If a person is in a dry room, then for him a dangerous voltage, which is over 36 volts. Death can occur when the current is 0.1 amperes. The current of 0.05 amps is also dangerous for life. The fact is that with such a power current there are convulsions that do not allow a person to move away from the source of the lesion.

If we are talking about static electricity, then this electricity is not a danger to human life. The maximum that the human body can sense from a blow of a spark discharge is an injection. A big danger to human life is the alternating current. Dangerous voltage for a person is over 50 V, and under adverse conditions (humidity, for example) is over 12 V. Dangerous current strength is 50 mA. It is the current of this force that can cause damage, and its effect on the human body within 5 s can become fatal.

Factors that affect the body during an electric shock

It is necessary to take into account not only the power of electric shock, but also what path of passage through the body it will have. It is worth remembering that the longer the current path through the human body, the heavier the consequences will be. As we have already said, an alternating current is considered dangerous for life, direct current does not affect the human body so destructively. There are a number of additional factors that can increase the danger:

1. Greater current.
2. Passing it through the body. It should be noted that different tissues of the body have different ability to resist, the current passes in most cases precisely through the blood vessels. Most frighteningly, when the current path runs along the entire body, for example, this can happen if the hand-legs are involved, then the current can pass through the heart, the dorsal or the brain. But sometimes a fatal outcome can occur when a hand-arm current passes, it all depends on how big the dangerous voltage was.
3. Time of exposure. The time interval that is allowed for a current action should not exceed 2 seconds.
4. Conductivity.
5. The area where the electric shock occurs.

It is impossible to calculate exactly how the current will affect the body. Human attention plays an important role, therefore, in hazardous locations, it is necessary to provide for safety a special sign on the safety equipment, which is called the "high voltage" sign.

What role does the resistance of the body play?

The resistance of the body depends on the condition of his skin, such factors can exert his influence:

1. In what state is the human skin, for example, it can be clean, can be dirty, wet, damaged.
2. What was the contact area of the current with the skin.
3. The magnitude of the applied voltage.
4. The current of what frequency passed through the body.
5. General condition of the human nervous system.

If the skin has been scratched or there are abrasions, then the dangerous stress may be minimal in order for death to occur, as the resistance of the body decreases. The ability to resist in a person who has a sweaty or dirty hand is lost. For example, a voltage of 30 volts with dry hands does not cause strong pain, and if you touch with a wet hand, the person will not be able to unclench fingers and will feel severe pain. In such cases, it is customary to say that there has been a breakdown of skin resistance.

Decrease the resistance of the skin can, even when exposed to low voltage, it is 20-40 volts.

What voltage is acceptable?

Statistics indicate that most of the injuries due to electricity occur as a result of touching bare wires. There are three safe voltages:

1. In a room where there is no increased danger, 65 volts are allowed.
2. In a room where there is danger - 36 volts.
3. In a room with increased danger - 12 volts.

In rooms of the second and third type, there must be a "high voltage" sign, which will warn of the danger. Often there is a defeat of employees who, by the nature of their employment, are required to work with a voltage of up to 1000 V, but neglect safety techniques and do not use protective equipment.

To answer the question of what kind of voltage is dangerous, it can be quite simple: any electric shock can cause damage, but the most dangerous is the voltage from 60 V, when paralysis of respiration and cardiac arrest may occur. But this can not happen if you carefully treat everything that surrounds a person and at least somehow relates to electricity. Personnel who work with high voltage and electric current must always remember the safety rules and be on high alert.

So, from this article you learned what tension is dangerous for life. We hope that this information will be useful to you.