The person who gets an electric shock will threaten the life safety of the person who gets an electric shock, and the degree of danger is related to the following factors:
(1) voltage passes through human body;
(2) Current passing through human body;
(3) the duration of the current action;
(4) frequency;
(5) The way the current passes through the human body;
(six) the physical condition of the electric shock;
(7) the body's resistance.
The degree of danger of the above factors is as follows:
Voltage across human body: Higher voltage is very harmful to human body, ranging from burning to death. Lower voltage can be borne by human body to avoid casualties. Judging from the voltage that people are exposed to, generally, except safe voltage below 36 volts, people above this voltage will be in danger. Current through human body: It depends on the voltage of the person who gets an electric shock and the resistance of human body. The higher the voltage the human body contacts, the greater the current passing through the human body. If it exceeds 0. 1 A, it may lead to electric shock death.
Duration of current action: the duration of current passing through human body is closely related to the degree of harm to human body. Under the action of electric current, the shorter the time, the greater the possibility of being rescued. The longer the current passes through the human body, the greater the damage to human function and the less likely it is to be rescued.
Frequency: Generally speaking, the power frequency of 50~60 weeks is the most dangerous to human body. From the point of view of electric shock, the risk of high-frequency current burns is no less than DC voltage and AC power frequency. In addition, radio equipment, high-frequency electrical equipment for quenching, drying and smelting can radiate electromagnetic waves with a wavelength of 1 cm to 50 cm. This electromagnetic wave can cause body temperature rise, physical fatigue, general weakness, headache and insomnia.
Ways of current passing through human body: When current passes through human body, it can burn epidermis, stimulate nerves and destroy the functions of heart and respiratory organs. The path of current through the human body, if it is from hand to foot, is the most dangerous when it passes through important organs (heart); If the current passes through the path from foot to foot, it is not so dangerous. In this way, the way the current passes through the human body when getting an electric shock determines the amount of current passing through the heart, as shown in the following table:
The percentage of the current passing through the heart to the total current passing through the human body (%)
From one hand to the other, from left hand to toe, from right hand to toe, from one foot to the other.
The physical condition of the person who gets an electric shock and the wet and dry condition of the skin: the human body is conductive, and when a voltage is applied to the human body after getting an electric shock, a current will flow. This current is related to people's physique and the degree of dryness and wetness of the skin at that time. When the skin is wet, the resistance is small, and when the skin is scraped, the resistance is even smaller, so the current flowing is large and the risk of electric shock is also great. At the same time, it also has a certain relationship with the health of those who get an electric shock. If the person who gets an electric shock has heart disease, neuropathy, etc. The risk is much greater than that of healthy people.
Resistance of human body: When people get an electric shock, it is related to the resistance of human body. The resistance of human body is generally between 10000~ 100000 ohms, especially the stratum corneum of skin. When the skin loses its cuticle, the human resistance will drop to 800~ 1000 ohm. If the skin is sweaty, wet and dusty (metal dust and carbon dust), the skin resistance will also be greatly reduced.