The main factors determining the affecting effect of electric current. Factors determining the outcome of electric shock

Electricity

According to modern ideas, electricity is a set of phenomena due to the existence, movement and interaction of electrically charged bodies or particles (electrons, ions, molecules, their complexes, etc.), and the electric current is an ordered and directed movement of electrons, ions. Accordingly, the electric current cannot be seen, but you can see, feel the results of the transformation of electricity to other types of energy: light, heat, mechanical energy, etc., which can not only benefit, but also impose irreparable damage as a result of violation of the rules for using this type of energy and in cases of emergency situations of natural and (or) technogenic (anthropogenic) character.

The physical parameters of the electric current are determined by the current, its frequency and native - variable or permanent.

Factors determining the outcome of electric shock

1. The magnitude of the current and voltage. Electric current as an amazing factor determines the degree of physiological impact on a person. The voltage should be considered only as a factor that causes the flow of a current in specific conditions - the greater the tension of the touch, the greater the damage.

According to the degree of physiological impact, the following damaging currents can be distinguished:

0.8-1.2 mA - threshold tangible current (i.e., the smallest current value that man begins to feel);
10-16 mA - a threshold inclusive (causing) current, when, due to a convulsive reduction, a person cannot free themselves from the current-carrying parts; may cause electrical asphyxia - a convulsive reduction in respiratory muscles in the phase of exhalation;
100 mA - causes fibrillation of the ventricles of the heart. It should be borne in mind that the likelihood of damage to such a current is 50% with the duration of its exposure of at least 0.5 s.

AC current from 100 mA to 5 A at a frequency of 50 Hz and a constant current from 300 mA to 5 A act directly to the muscle of the heart, which is very dangerous for life, because after one or two seconds, from the moment of closing the circuit of this current through a person, fibrillation may occur - scattered, arrhythmic and non-coordinated reductions in individual groups of muscular fibers of the ventricles of the heart with a frequency of more than 300 reductions per minute. At the same time, the heart ceases to perform its pumping functions, and the blood supply to the entire body ceases.

The current is more than 5 A, as a rule, the heart fibrillation does not cause. With a further increase in the current, it acquires defibrive properties, but causes a violation of the CPS functions and the respiratory stop of the central genesis.

2. Duration of current exposure. It has been established that electric shock is possible only in a state of complete rest of the human heart, when there is no compression (systole) or relaxation (diastole) of the ventricles of the heart and atrial. Therefore, at a small time, the exposure of the current may not coincide with the phase of complete relaxation, but everything that increases the tempo of the heart of the heart, contributes to increasing the probability of stopping the heart when the current is shocking any duration. Such reasons include: fatigue, arousal, hunger, thirst, fright, adopting alcohol, drugs, some drugs, smoking, disease, etc.
3. Body resistance. The value is inconstant, depends on the specific conditions, changes from several hundred ohm to several mega. When exposed to an industrial frequency voltage of 50 Hz, human body resistance is an active value consisting of internal and external components. Internal resistance in all people is approximately the same and amounts to 600-800 ohms. Various parts of the body and human tissue have a different current resistance: bones -
200 Ω; cartilage - 50 000 ohms; Muscles - 1500 ohms; liver - 900 ohms; The mucous membranes are 100 ohms.

The skin is 10,000-20,000 ohms, especially thick and dry skin on the palms and soles - 2 MΩ.

From this we can conclude that the outcome of injury will be depends on the location of the current application.

Body resistance is not a constant value: in conditions of high humidity, it decreases 12 times, in water - 25 times, sharply reduces its adoption of alcohol.

4. Current power. The strength of the current is determined by the ratio of the voltage and resistance of the body through which it passes (/ \u003d U / R.).

Dry skin has a resistance of 0.1-2 mΩ, and wet 1 com. Thus, the current of the same voltage, for example, in 127 V, may in some conditions (dry skin) do not cause serious damage (easy tingling), and in others (wet skin, raw floor) - lead to death from ventricular fibrillation. The strength of the current in the nerve will be equal to 1.27 mA, and in the second - 127 mA.

With increasing voltage of more than 500 per magnitude of the skin resistance no longer matters, since the "test" of the skin occurs at the point of contact, the "Tags" of the current occurs.

The variable current with a frequency of 50 Hz is more dangerous in industry and in everyday life than the constant current of the same voltage. This position concerns current to 500 V. With this voltage, the risk of both generics is equalized, and at a voltage above 500 per direct current is more dangerous than variable.

Path ("loop") current through the human body. In order to investigate accidents related to the effects of electric current, it is primarily finding out how the current flowed. The current at the entrance to the body branches, the main amount of electricity rushes in a straight line from the anode to the cathode. A person can touch the current-carrying parts (or metal inadvertent parts that can be under voltage) with various parts of the body. From here there is a variety of possible treads. The most likely ways are recognized as follows:

"Hand is hand" (40% of cases of lesion);
"Right hand - legs" (20%);
"Left hand - legs" (17%);
"Both hands - legs" (12%);
"Leg - leg" (6%);
"Head - legs" (5%).

All loops, except the hinge "Noga - Leg", are called "big", or "full" hinges, as the current captures the heart area. In these cases, 8-12% of the total value of the current flows through the heart. The hinge "foot - leg" is called "small", through the heart takes place only 0.4% of the total current. This loop occurs when a person turns out to be in the zone of current spreading, falling under step tension.

Stepper is called the voltage between the two points of the Earth, due to the spreading of the current in the ground, while simultaneously touching their legs of a person. At the same time, the wider step, the larger the current flows through the legs. Such a current of the current does not carry a direct danger of life, but under its influence, a person may fall and the flow of current flow will become dangerous for life. For protection against step stress, additional protection means are dielectric bots, dielectric mats. In the case when the use of these funds is not possible, the spreading zone should be left so that the distance between the feet standing on the ground was minimal - short chains. It is also safe to move on a dry chalkboard and other dry items that are not conducted.

The nature and consequences of the effect on the human electrical current are determined by the electrical resistance of the human body, voltage of the current and the duration of the electric current, depend on the current cycling through the human body, genus and the frequency of the electric current, as well as the conditions of the external environment.
Electrical resistance of human body. The human body is an electric current conductor, though heterogeneous electrical resistance. The highest electrical current resistance is leather, so the overall resistance of the human body is determined mainly by the size of the skin resistance. The skin consists of two main layers: external - epidermis - and internal - dermis.
The outer layer - in turn, has several layers, of which the fastest top layer is called a horny.
The horny layer in a dry ungadst condition can be viewed as a dielectric. Its specific volume resistance reaches 105-106 Ohm M, thousands of times the resistance of other layers of skin (dermis) and internal tissues of the body.
The resistance of the human body with dry clean and intact skin (measured at a voltage of 15-20 V) ranges from 3 to 100 com and more, and the resistance of the inner layers of the body is only 300 - 500 ohms.
For calculations, the amount of human body resistance is taken equal to 1000 ohms.
In fact, the resistance of the human body is not constant. It depends on the state of the skin, the environment, the parameters of the electrical circuit, etc.
Damage to the horn layer (cuts, scratches, abrasions) reduce body resistance up to 500 - 700 ohms, which increases the risk of human damage to the current.
The same effect has moisturizing the skin with water or sweat. Therefore, work with electrical installations with wet hands and under conditions causing moisturizing the skin, and at elevated temperatures exacerbates the danger of human damage to the current.
Contamination of the skin with harmful substances that are well conducted by electric current (dust, scale), also leads to a decrease in its resistance.
Maintain an area of \u200b\u200bcontact and touch location, since skin resistance is not sourinakovo at different parts of the body. The smallest resistance is the skin of the face, neck, palms and hands, especially on the side facing the body (armpits, etc.). The skin of the back side of the brush and the soles has resistance, many times greater than the skin resistance of other parts of the body.
Current and voltage. The main factor determining the outcome of the human damage to the electric current is the strength of the current passing through its body (Table 20.1). With an increase in the strength of the current, the human body resistance drops, as the local heating of the skin is enhanced, which leads to the expansion of the vessels, strengthening the supply of this section with blood and increase the removal.
The voltage attached to the human gel also affects the outcome of the lesion, since it determines the value of the current force passing through a person, the voltage rist leads to a breakdown of the horn layer of the skin, skin resistance decreases in tens
Table 20.1. Threshold values \u200b\u200bof various current types

* Instant heart stop occurs at a current equal to 5 A.

once, approaching the resistance of internal fabrics (300 - 500 Ohms), increase the strength of the current accordingly.
Rod and electric current. Permanent current about 4 - 5 times safer variable. This follows from the comparison of the speaking values \u200b\u200bof tangible and uncommitable constant and alternating currents. But this is true only to voltages 250 - 300 V. With a bothe of high voltage values, the constant current becomes more dangerous than the variable (with a frequency of 50 Hz).
As for alternating current, its frequency is important. With an increase in the frequency of AC, the complete impedance of the body decreases at 10 to 20 kHz, the outer layer of the skin almost loses its electric current resistance, which also leads to an increase in the current passing through a person, and therefore, the danger of lesion increases.
The greatest danger represents a current with a frequency of 50 to 1000 Hz. With a further increase in the frequency, the danger of lesion decreases and completely disappears at a frequency of 45 - 50 kHz. These currents are dangerous only in terms of burns. Reducing the risk of lesion with an increase in frequency becomes almost visible at 1-2 kHz.
Duration of electric current. The prolonged effect of electric current leads to heavy, and sometimes fatal human lesions.
A long-term exposure to the current of 1 mA is considered safe, with duration of validity of up to 30, 6 mA is safe.
Almost admissible with a rather small probability of lesion adopted the following values \u200b\u200bof the current strength:
Exposure duration, with current, ma
1,0 50 7 70
0,5 100
0,2 250
The path of passing the current through the human body. This factor also plays a significant role in the outcome of the lesion, as the current can pass through the vital organs - the heart, light, brain, etc.
Possible p ^ tapes passing through the human body, which are also called current loops, quite a lot. The most common loops of the current - hand - hand, hand - legs and leg - leg - presented in table. 20.2.
The most dangerous those that may affect the area of \u200b\u200bthe heart, i.e., the head - hands and head - legs. But they arise relatively rarely.
Table 20.2. Characteristics of the flow paths through the human body,%

Individual properties of man. It has been established that physically healthy and strong people are easier to carry electrical shocks.
Increased electric current susceptibility, persons suffering from skin diseases, having diseases of the cardiovascular system, internal secretion and lung organs, nervous diseases, etc.
Safety rules for the operation of electrical installations provides for the selection of personnel for servicing existing electrical installations, based on the health status of people. For this purpose, they are conducting a medical examination of persons when entering them to work, which is periodically repeated once every two years, taking into account the list of diseases and disorders that are contraindicated to servicing existing electrical installations.
Conditions of the external environment. The state of the surrounding air environment, as well as the surrounding environment can significantly affect the danger of damage to the current.
Dampness, conductive dust, the presence of caustic vapors and gases that are destructive on the insulation of electrical installations, as well as the high ambient temperature, reduce the electrical resistance of the human body, which further increases the danger of damage to the current.
The effect of current on a person is also aggravated by conductive floors and close-up metal structures that are connected to electrical equipment, having a connection with the Earth, since with the simultaneous touch of this item and body of electrical equipment, randomly produced by stress, through a person a lot of power will pass through a person.
Depending on the listed conditions that increase the danger of current impact on a person, the "rules of the electrical installation device" all the premises for the danger of lesion of people by electric current are divided into four classes. Premises without increased danger. Characterized by the absence of conditions that create an increased or special danger (PP. 2 and 3). Premises with increased danger. Characterized by the presence of one of the following conditions:
a) dampness (when the relative humidity of the air exceeds 75%) or conductive dust;
b) conductive floors (metal, earthy, reinforced concrete, brick, etc.);
c) high temperature (above 35 ° C);
d) the possibility of simultaneously touching a person to having a compound from the ground with metal structures of buildings, technological apparatus, mechanisms, etc., on the one hand, and to metal electrical hulls, on the other. Particularly dangerous premises. Characterized by the presence of one of the following conditions:
a) special dampness (with relative humidity of air, close to 100%, when the ceiling, walls, floor and objects located indoors are covered with moisture);
b) chemically active or organic medium, destructive insulation and current-carrying parts of electrical equipment;
c) the presence of two or more conditions of increased danger at the same time (p. 2). Territory area of \u200b\u200bexternal electrical installations. By the danger of lesion of people with electric shock, these territories are equal to particularly dangerous premises.
In the chemical industry, many industrial premises are particularly dangerous.
In addition, depending on the climatic medium, the premises are divided into: dry (normal) with humidity up to 60%, wet (60 - 75%), raw (more than 75%), especially raw (with humidity close to 100%), Hot (at a constant temperature above 35 ° C), dusty, premises with a chemically active or organic medium.
Electrical equipment should be selected taking into account the state of the environment and the class of premises for the danger of damage to the current in order to ensure the necessary degree of people's safety during its service.
Thus, electrical equipment installed in raw, especially raw and dusty rooms, as well as indoors with a chemically active medium, should be closed, have the appropriate version: a drop-or splash-proof, dustproof, blurred. In addition, the materials from which electrical equipment is made should be corrosion-resistant, and metal parts are securely protected by paintwork or galvanic coating.
Electrical equipment and electrical networks placed in rooms with a chemically active medium, as well as their places of laying, should be selected taking into account the execution and coating that ensures their protection against the effects of the aggressive environment.
In the explosive zones "of all classes with chemically active media, wires and cables with polyvinyl chloride insulation are used, as well as wires with rubber and cables with rubber and paper insulation in a lead or polyvinyl chloride sheath. The use of wires and cables with polyethylene insulation in any shell and coatings are prohibited.

1. Electric human body resistance.

2. The energy of the potential difference in the electrical circuit.

3.Translate exposure.

4. Put current through the human body.

5. The driver and the frequency of the electric current.

6. Individual properties of a person.

7. conditions of the external environment.

1. Human body resistance.

The highest electrical current resistance is leather, therefore the resistance of the human body is determined mainly by the skin resistance. The electrical resistance of the human body with dry, clean and intact skin, measured at 20 V, ranges from 3-100 com, and the resistance of the internal layers is 300-500 ohms. The electrical resistance of the human body is a complex value, consists of active and capacitive, but, as a rule, the capacitive neglect. The smallest resistance is the skin of the face, neck, hands on the site above the palm, especially in areas facing the body. With an increase in exposure time, the human body resistance drops, since the local heating of the skin is enhanced, which leads to the expansion of the vessels and enhancing the supply of this section with blood, and accordingly increase the removal.

Tangible current- Electric current causing tangible irritations when passing through the body. For AC - this is 0.6-1.5 mA, for DC 5-7 mA.

Unknown current- Electric current causing irresistible convulsive cuts when passing through the body. For AC, it is 10-15 mA, for DC 50-60 mA.

Fibrillation current - electric current in which unynchronous reductions of the heart muscle may occur. The threshold current for AC is 100 mA, for permanent - 300 mA. With the duration of exposure to 1-2 seconds along the way, the hand is hand or hand - the legs fibrillation current can reach 5 A. more than 5 And the heart fibrillation does not cause - an instantaneous heart stop occurs.

5. Rod and electric current.

Permanent current is approximately 4-5 times safer variable. A much smaller danger of damage to constant current is confirmed by the practice of exploitation of electrical installations. This position is valid only for voltages 250-300 V. But a greater danger represents an alternating current with a frequency of 50-1000 Hz, with a further increase in frequency, the danger of lesion decreases and completely disappears at a frequency of 45-50 kHz.

6. Individual properties of man.

It has been established that physically healthy and strong people are easier to carry electrical shocks. Highly susceptibility to electric currents have people suffering from diseases of the cardiovascular system, skin, internal secretion organs.

7. Conditions of the external environment.

Dampness, conductive dust, caustic pairs and gases are destroying for insulation of electrical equipment. The effect of current on a person is also aggravated by conductive floors and close metal and grounded structures close to electrical equipment.

Premises for the danger of electric shock are divided into:

1) premises without increased danger;

2) Premises with increased dangers that are characterized by the presence of one of the following conditions:

Dampness or conductive dust;

Conductive floors;

High temperature room (over 35 s);

The possibility of simultaneously touching a person to grounded metal structures on one side and to the metal housings of electrical equipment on the other.

3) Particularly dangerous premises - are characterized by the presence of one of the conditions:

Special damp (relative humidity of approximately 100%);

The presence of a chemically active or organic medium;

The presence of at the same time two or more conditions of increased risk.

These are vividly pronounced local (local) damage to body tissues caused by the effect of electric current or electric arc. Local damage is most often exposed to the surface of human skin, but in some cases muscle tissues are affected, as well as ligaments and bones. Typically, local electricians are cured by human performance fully or partially restored. However, in some cases, local electricians lead to the death of a person. To local electricians include:

· Electric burns,

· Electrical signs (current tags),

· Electrometallization of the skin,

· mechanical damage,

· Electrophthartmia.

Electric blow is the effect of electric current on the human or animal body, as a result of which the convulsive contraction of the muscles of the body begins. Depending on the value of current and the exposure time, the biological object may be in or without or without it, but with the independent functioning of the respiratory organs and the cardiovascular system. In the most difficult conditions, after defeating, the current is observed not only the loss of consciousness but also the problems in the work of the cardiovascular system, and even the fatal outcome.

23. The sequence and content of first aid activities. Ways to liberate electric current affected, personal safety measures. Features of the defeat of atmospheric electricity (zipper) during thundering discharges, first aid.

The first aid when electric shock is shred to the immediate disconnection of the electrical installation or interrupting an absolutely any available method of electrical current effects per person, then depending on the degree of lesion, it will begin to perform a closed heart massage and organization of artificial respiration in case the victim has a heart stop, as well as processing and imposing bandages on the affected parts of the body.

With electric shock damage, it is necessary to free the victim affected by its impact as soon as possible, since the severity of the electric travelers depends on the duration of this action.

If the victim holds the wire with his hands, his fingers are strongly compressed and the wire is not possible, then the first action of the help affecting the electrical installation, which concerns the victim. Disconnection is performed using switches, switch or other non-disconnecting device, as well as removing or retrieving fuses (plugs), plug connector.

With the disconnection of the electrical installation, artificial lighting can simultaneously go out, so it is necessary to take care of this by turning on emergency lighting and so on.

At the same time, it is necessary to take into account the explosion hazard and fire hazard of the room. Providing assistance to the victim, it is impossible to touch him without complying with precautions, as it is dangerous for life; It is necessary to ensure that it is not to be in contact with the current-carrying part and under stepper voltage.

For separating the victims of the current-carrying parts or wire, the voltage to 1,000 in must use a rope, a stick, a board, or a different dry item that does not conduct an electrical current.

If the clothes are dry and lag behind the body, then you can pull the victim from the current-carrying parts, avoiding contact (touch) with parts of the body, for the floors of a coat or jacket, jackets for the collar.

For the isolation of hands, providing assistance must wear dielectric gloves or wrapped the hand with a scarf, put a cloth cap on the hand or stretch the sleeve of a jacket or coat on the hand. You can isolate yourself by applying a rubber rug, a dry board or other technician items that do not conduct an electric current (litter, a bundle of clothing).

If the electric current passes to the ground through the victim, and he convulsively squeezes the wire in his hand, it is possible to separate a person from the ground, snapped under it a dry board or pulling off for clothes. You can also reflect the wire with an ax with a dry wooden handle or other tools with insulated handles (passports, etc.).

After the release of the affected operation of the electric current, it is necessary to estimate its condition.

If the victim does not have consciousness, breathing, pulse, shiny leather cover, and pupils are wide (0.5 cm with a diameter), then it is in a state of clinical death and immediately begin to revive the organism with an artificial respiration by the way "mouth in the mouth" or "mouth to the nose" and the outdoor heart massage.

Starting reviving the victim, it is necessary to take care of the call of medical care.

In the body of the victims of the affected by atmospheric electricity, the same pathological changes are noted as with electric shocks. The victim loses consciousness, falls, convulsions can be marked, breathing and heartbeat often stops. On the body, you can usually detect the "current tags", the location of the entrance and the exit of electricity. In the event of a deadly outcome, the reason for the termination of the main life functions is a sudden stop of breathing and heartbeat, from the direct action of the lightning on the respiratory and vasomotor centers of the oblong brain. The affected by the impact of lightning needs hospitalization, as it is subject to the risk of electrical activity of the heart.

Under the damage to the zipper, the same assistance turns out to be electric shock.

The affected lightning immediately make artificial respiration, when the heart is stopped - its closed massage and warming the body. Inside give caffeine, analgin. If possible, subcutaneously anti-depository means are introduced: Promedol, caffeine, ephedrine. After recovering the respiration of the victim, you should drink hot tea, process burns and transported to the hospital.

24. Flame burns, sequence and content of first aid activities. Furgence, first aid activities (stages).

Burn – tissue damage caused by the impact of high temperature, chemicals, electric current, ionizing radiation. Depending on the cause of the occurrence, thermal, chemical, electrical, radial burns are distinguished. Sunburns are possible. Most often there are thermal burns.

Thermal burns. In case of fires on the human body, there are several amazing factors. The most dangerous of them is a high temperature in the burning area, leading to thermal impact, skin burns and upper respiratory tract. Burns with flames proceed much harder than boiling fluid burns. Among the thermal burns of various localization are a special danger represent face burns, they are accompanied by upper respiratory burns hot air.

The severity of the condition of the victim depends on the degree of burn, its area and localization. The degree of burn is determined by the depth of lesion of the skin and the tissues to be tissue. Eliminate IV burns of burns.

Burn I degreemanifested by redness of the skin, swelling, pain.

Burn II degreeit is distinguished by the formation of bubbles filled with a transparent yellowish liquid, sharp redness of the skin, burning pain.

Burn III degreeit is accompanied by the first leather layers. The burn surface is covered with grip - a dense gray-brown crust. Due to the damage to the nerve endings, the pain is insignificant or absent. Dead fabrics are caught up and rejected. Healing flows slowly. On the scene of the burn is formed by a scar.

Burn IV burnit is characterized by char harness, subcutaneous fatty fiber, muscles, and even bones. Pain sensitivity is lost. For healing deep burns need skin transplant.

Definition of Ozog's Square

The burn area is determined by the "Government of Nine". The surface of the head and neck is 9% of the body's surface of an adult, one upper limb - 9%, one lower limb - 18% (hip - 9%, shin and stop - 9%). The rear surface of the human body is 18% of the body surface, the front surface (breast, belly) - 18%, crotch and external genitals - 1%.

The area of \u200b\u200bthe burn can also be determined by "Palm Regulation". The area of \u200b\u200bthe victim's palm is 1% of the surface of his body. Palm is projected over the area of \u200b\u200bthe defeat, without touching the burned area of \u200b\u200bthe body.

The burns of more than 15% of the body surface in adults are accompanied by a burn shock. In children, the burn shock develops with 5 - 10% and more burns. 2 phases of the burn shock are isolated: the first is the excitation phase, the second - braking. The first phase is characterized by short-term. The victims are excited, restless due to the continuous intake of pain impulses from burn wounds. The second phase is characterized by a pronounced oppression of the activity of the nervous system, heart, lungs, kidney and other organs. The indifferent look of victims is attracted. Danger for life occurs even with burns of II, which occupy the surface of the body.

With extensive burns in places of lesion, toxic substances are formed. Penetrating into the blood, they are spread throughout the body and cause intoxication. Microorganisms fall on the burned areas of the skin, burn wounds begin to appreciate. The burn disease develops. The deeper the lesion of the skin and the fabrics to be tissue and more area of \u200b\u200bthe burn, the hardest state of the victim and worse the forecast.

Furgence - damage to body tissues under the influence of cold. Frostime is more susceptible to fingers and legs, nose, ear shells and face. The severity of frostbite depends on the duration of the action of the cold, as well as on the state of the body.

With alcoholic intoxication, the thermoregulation of the body is disturbed, and the likelihood of frostbite increases! Sign: a sharp pale of the skin and loss of its sensitivity. The main task of first aid is the cessation of cold exposure and as quickly as possible restoration of the normal temperature of the cooled tissue. For this you need:

immerse the frostite parts of the body into water with a temperature of from 37 ° C to 40 ° C, but not higher due to the hazard of the burn;

make a slight rubbing of frostbitten skin.

It is forbidden to rub the frostbitten sections with snow or immerse them into cold water, since it takes further supercooling!

To prevent infection on frostite areas, sterile dressings are superimposed. When pain, tissue edema, bubbles need to seek medical help.

Imagine that you take your own hands for the cereal wires that are under high voltage, and you do not have an electric shock. Great. But this is possible in two cases: if you have reliable rubber gloves on your hands or if your skin is a very good dielectric (which the ordinary people are not observed). Unfortunately, human leather is a bad dielectric, and therefore the contact of people with electricity, as a rule, ends with all sorts of injury and fatal outcome.

The external factors of the electric shock of man are the magnitude of the current passing through the body, the duration of exposure, the generation (permanent, variable), its frequency, etc.

But the outcome of the defeat also depends on the person itself. This affects the resistance of the human body. The body resistance depends on the state of the body, skin cover, its humidity, emotional state, etc.

Usually, a person is able to feel the effect of an electric current of a small value: 0.6-1.5 milliamper (with an alternating current with a frequency of 50 Hz) and 5-7 milliamper (at constant). This electrical current value has the name "threshold tangible current". High current values \u200b\u200bare capable of providing involuntary muscle contractions and rather painful sensations that increase with increasing current, affecting all large parts of the body.

With the values \u200b\u200bof the AC in 10-15 mA, the pain becomes intolerable, and the contraction of the muscles of a person acquire the state of irresistibleness. As a result, a person is not able to independently open his hand, in which there is a conductive conductor with a voltage. Such currents are called "irrecoming". For DC, its value corresponds to 50-80 mA.

A variable electric current with a force of 25-50 mA (50 Hz) acts on the muscles not only hands, as well as the torso, where the most dangerous zone is the chest. In this case, there is a strong difficulty of breathing. The prolonged effect of currents of this magnitude is able to cause even a complete cessation of breathing, after which death comes from suffocation.

A variable electric current (50 Hz) with a value of 50 mA and up to 100 mA is also faster than the normal activity of the heart and lungs. In this case, as, however, and at lower currents, light, and the heart and heart are affected by the first time.

A variable electric current (50 Hz) with a value of 100 mA to 5 A and permanent current from 300 mA to 5 and the first thing affects the heart muscle, which is extremely dangerous for the human life, because after one or two seconds after the start of the electric strike, fibrillation occurs after the start of the electric impact (chaotic reduction of cardiac fibers). At the same time, the heart ceases to work as a pump, which stops blood circulation in the body. This will attract the lack of oxygen and stop breathing. Next clinical death. If for 7 minutes it is not to revive a person, then clinical death goes into constant.

Electric current with a force of more than 5 amps usually does not cause heart fibrillation, because with such values \u200b\u200bof the current immediately, the heart stops. Next, palsy of breathing and again clinical death.

If the effects of the electric current were short-term (up to 1 - 2 seconds) and did not entail the heart stop (as a result of the burn, heating, etc.), then after the current termination, the heart usually renews its work itself, and there is no breathing. Therefore, emergency assistance is needed in the form of artificial respiration (mouth in the mouth or mouth in the nose).

An important factor for electric shock is the path of passing this current through the human body. If there are vital organs on this path: light, heart, head and spinal cord, the lesion becomes very dangerous, since the effect of current leads to a violation of their work. If the electric current passes through other ways, then the danger to life is sharply reduced.

P.S. As practice shows, a constant current of 4 - 5 times is safer, compared with the variables (50 Hz). But this applies to stresses up to 250-300 V. Be careful and careful when working with electricity!

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Ministry of Transport of the Russian Federation

Federal State Budgetary Educational Institution of Higher Professional Education

"Ulyanovsk Higher Aviation School of Civil Aviation (Institute)"

Department of search and rescue support

abstract

Factors determining the danger of electric shock

Compiler: Dyachenko M.V

Leader: Shuekov V.V.

Ulyanovsk 2014.

Introduction

1. The effect of electric current on the human body

1.1 Types of electric shock

1.2 Electric Strike

1.3 Human Body Resistance

1.4 The main factors affecting the outcome of the lesion of the current

2. Conditions and reasons for which the current is defeated

3. Measures to ensure electrical safety in production

3.1 Organizational Protection Measures

3.2 Organizational and technical protection measures

Conclusion

List of used literature

INmaintenance

Russia is a worker country. According to statistical data for January 2014, the number of economically active population in Russia - 52% (74.6 million people). The percentage of unemployed for January 2014. is 5.6%, i.e. 4.2 million person. Thus, working in our country - 70.4 million people.

It is noteworthy that almost all professions today can somehow come into contact with the use of electricity.

The electric current represents a serious danger to a person's life, so the task of ensuring electrical safety is very and very serious.

Electrical safety is a system of organizational and technical measures and funds to protect people from the harmful and dangerous effects of electric current, an electric arc, an electromagnetic field and static electricity.

There are constant and variable electrical current. Today, the use of alternating current with a frequency of 50 Hz to 300 GHz is common.

We will analyze this range in more detail:

1. Industrial frequency current, 50 Hz, used in electrification systems of production and life.

2. Low frequency current, 3-300 kHz - in broadcasting, when smelting, welding, heat treatment of metals.

3. Current of medium frequency, 0.3-3.0 MHz - in broadcasting, with inductive heating of metals and other materials.

4. The current of high frequency, 3.0-30 MHz - in broadcasting, television, in medicine, when welding polymers.

5. The current is very high frequency, 30-300 MHz - in broadcasting, television, in medicine, when welding polymers.

6. Current of ultra-high frequency, 0.3-3.0 GHz - in radar, in multichannel radio communications, in radio astronomy during sterilization and cooking, etc.

7. Current super high frequency. 3-30 GHz

8. The current is extremely high frequency, 30-300 GHz.

In this paper, I will consider the factors that determine the danger of electric shock and the main causes of electricians, as well as measures to prevent and prevent.

1. Effect of electric currenton the human body

1.1 Viewelectric shock lesions

Passing through the body, the electric current produces 3 types of exposure : thermal, electrolytic and biological.

Thermalthe action is manifested in burns of external and internal parts of the body, heating blood vessels and blood, etc., which causes serious functional disorders in them.

Electrolyticthe action is expressed in the decomposition of blood and other organic fluid, thereby causing significant violations of their physicochemical compositions and tissues in general.

Biologicalthe action is expressed in the irritation and excitation of living tissues of the body, which can be accompanied by involuntary convulsive cuts of muscles, including muscles of the heart and lungs. At the same time, various disorders in the body can occur, including mechanical damage to tissues, as well as violation and even complete termination of the activities of respiratory and blood circulation.

Distinguish two main types of body defeat: Electrical injuries and electric shocks. Often both types of damage accompany each other. Nevertheless, they should be considered separately.

Electrical injuries - These are clearly pronounced local disorders of the integrity of the body tissues caused by the effects of electric current or electric arc. It is usually superficial damage, that is, skin lesions, and sometimes other soft tissues, as well as ligaments and bones.

The danger of electrical injuries and the complexity of their treatment are caused by the character and degree of tissue damage, as well as the body's reaction to this damage.

Typically, injuries are cured and the performance of the victim is restored in whole or in part. Sometimes (usually, with heavy burns), a person dies. In such cases, the immediate cause of death is not an electric current, but local damage to the body caused by the current. Characteristic types of electrical injuries - electric burns, electrical signs, leather metallization and mechanical damage.

Electric burn - The most common electrical injury: burns arise from most of the affected by electric current (60-65%), and the third of them is accompanied by other injuries - signs, metallization of the skin and mechanical damage.

Depending on the conditions of the occurrence differ three types of burns:

current, or contactarising from the passage of current directly through the human body as a result of a person's contact with the current-carrying part; This kind of burn occurs in electrical installations of relatively small voltage - not higher than 1-2 kV and is, as a rule, burn skin, that is, external damage;

arc, due to the impact on the human body of the electric arc, but without passing the current through the human body; Usually, these burns are the result of random short circuits in electrical installations of 220-6000 V, for example, when working under voltage on shields and assemblies, when performing measurements by portable devices, etc.;

mixed, which is the result of the action of both these factors simultaneously, that is, the actions of the electrical arc and passing the current through the human body; This burn occurs, as a rule, in the rates of higher voltage - above 1000 V. The arc is formed between the current-carrying part and the person, and the current, which is usually of great importance (several amps and even dozens of amps), passes through the human body. In this case, the defeats are severe in nature and often end the death of the victim, and the severity of the lesion increases with an increase in the voltage of electrical installation.

The electrical signs also referred to as current and electrical label signs are clearly defined stains of gray or pale yellow color on the surface of the skin of a person who has exploited current. Often signs have a round or oval shape with a deepening in the center; Sizes of signs 1-5 mm. The affected area of \u200b\u200bthe skin solidifies like corn. As a rule, electrical signs are painless and the treatment ends safely: over time the top layer of the skin comes down and the affected place acquires initial color, elasticity and sensitivity. Signs arise quite often - about 20% of current victims.

Metalization of the skin - penetration into the skin of the smallest particles of molten under the action of the electric arc of the metal. This phenomenon occurs with short circuits, disconnects disconnectors and switches under load, etc. The affected skin area has a rough, rigid surface. Sometimes there is redness of the skin caused by the burn, due to the heat listed in the skin with the metal. The victim feels on the affected area the tension of the skin from the presence of a foreign body in it, and in some cases he has pain from burns.

Usually over time, the sore leather comes down and the affected area acquires a normal look. At the same time, all the painful sensations associated with this injury disappear.

Skin metallization is observed about each tenth of the victims. Moreover, in most cases, a stroke of an electric arc occurs simultaneously with metallization, which almost always causes more severe lesions.

Mechanical damage is a consequence of sharp, involuntary convulsive muscle contractions under the action of the current passing through a person. As a result, skin breaks, blood vessels and nervous tissue, as well as dislocations of joints and even bone fractures can occur.

1.2 Electric strike

Electric strike - This is the excitation of living tissues by electrical current passing through the body, accompanied by involuntary convulsive cuts of muscles. Depending on the outcome of the negative effects of the current on the body, electrical strikes can be conditionally divided into the following four degrees:

1. Facial cuts of muscles without losing consciousness;

2. Supporting muscles with loss of consciousness, but with the preserved breathing and work of the heart;

3. Loss of consciousness and violation of cardiac activity or breathing (or both together);

4. Clinical death, that is, the absence of breathing and blood circulation.

Clinical (or "imaginary") death is a transitional period from life to death coming from the moment of termination of activities and lungs. In a person who is in a state of clinical death, there are no signs of life, it does not breathe, his heart does not work, pain irritations do not cause any reactions, the pupils of the eyes are expanded and do not react to light. However, during this period, life in the body has not yet completely faded, because the fabric does not die immediately and do not immediately fade the functions of various organs. These circumstances allow you to restore fuses or just fastened the functions of the body, that is, revitalize the dying organism.

The first to die very sensitive to oxygen starvation of the cerebral cells, with the activities of which are associated with consciousness and thinking. Therefore, the duration of clinical death is determined by the time since the cessation of cardiac activity and respiration before the death of the cells of the cerebral cortex; In most cases, it is 4-5 minutes, and with a death of a healthy person from a random cause, for example, from electric current - 7-8 min.

Biological (or true) death - irreversible phenomenon characterized by the cessation of biological processes in the cells and tissues of the body and the decay of protein structures; She comes after a period of clinical death.

Death causes from electric current There may be cessation of heart work, cessation of breathing and electric shock.

The cessation of cardiac activity is a consequence of the effect of current on the heart muscle. Such an impact can be direct when the current flows directly in the region of the heart, and reflex, that is, through the central nervous system, when the current path is outside this area. In both cases, a heart stops may occur or its fibrillation can occur, that is, randomly fast and time-based cuts of the fibers (fibrils) of the heart muscle, in which the heart ceases to work as a pump, resulting in a blood circulation in the body.

Starting breathing As the root cause of death from the electric current is caused by the immediate or reflex exposure to the current on the chest muscles involved in the respiratory process. A person begins to experience difficulty breathing at a current of 20-25 mA (50 Hz), increasing with increasing current. With long-term action of the current, asphyxia can be hit as a result of lack of oxygen and excess carbon dioxide in the body.

Electric shock - a peculiar severe nervous reflex reaction of the body in response to strong irritation by electric shock, accompanied by hazardous circulatory disorders, respiration, metabolism, etc. Shock state lasts from several tens of minutes before a day. After that, it may be to step up or the death of the body as a result of a complete fading of vital functions or complete recovery as a result of timely active medical intervention.

1.3 Electricsome human body resistance

The human body is an electric current conductor. Various body tissues have a current different resistance: leather, bones, adipose tissue - large, and muscle tissue, blood and especially spinal and brain - small. The skin has a very large resistivity, which is the main factor determining the resistance of the entire body of a person.

The resistance of the human body with dry, clean and intact skin (measured at a voltage to 15-20 V) ranges from about 3,000 to 100,000 Ohms, and sometimes more.

Usually, with an alternating current of industrial frequency, only the active resistance of the human body takes into account and take it equal to 1000 ohms. In fact, this resistance is a variable value that has a nonlinear dependence on a plurality of factors, including from the state of the skin, the parameters of the electrical chain, physiological factors and the state of the environment.

Skin condition - Very strongly affects the magnitude of the resistance of the human body. Thus, damage to the horn layer, including cuts, scratches, abrasions and other microtravami, can reduce the total body resistance to a value close to the internal resistance value, which certainly increases the risk of human damage to the current. The same effect also has moisturizing the skin with water or by sweat, as well as contamination of the skin with dust or mud.

Since one tale of the skin is unenocomy in different parts of the body, then the resistance as a whole is the place of contact application, as well as their area. The current and the duration of its passage through the body have a direct impact on the full resistance: with increasing current and time of its passage, the resistance drops, since the local heating of the skin is enhanced, which leads to the expansion of its vessels, and consequently, to enhance the supply of this section with blood and increasing Sweating.

1.4 Basic factorsshooting on the outcome of damage

The magnitude of the electric current passing through the human body is the main factor caused by the outcome of the defeat. At the same time, the duration of exposure to current, its frequency, as well as some other factors. The resistance of the human body and the magnitude of the applied voltage also affect the outcome of the lesion, but only there is an extent, since they determine the value of the current passing through the person.

Man begins to feel the effect of current passing through it Low size: 0.6-1.5 mA with alternating current with a frequency of 50 Hz and 5-7 mA at a constant current. This current is called a threshold of tangible currents or a threshold tangible current. The bulk currents cause muscle cramps and unpleasant painful sensations, which with increasing current increase and apply to all the brutal parts of the body. At 10-15 mA, pain becomes barely portable, and the cramps of the muscles of the hands turn out to be so significant that a person is not able to overcome them; As a result, he cannot break the hand in which the current-carrying part is clamped, it cannot discard the wire, etc., that is, it is not able to impact contact with the current part independently and it turns out to be chained to it. The same effect is also produced by currents of the brutal value. All this currents are called irrevocable, and the smallest of them - 10-15 mA at a frequency of 50 Hz (and 50-80 mA at a constant current) is called the inconsistent current threshold or a threshold unwitting current.

The current 25-50 mA at a frequency of 50 Hz acts on the muscles not only the hands, but also torso, including on the muscles of the chest, as a result of which the breath is greatly difficult. The prolonged effect of this current may cause the cessation of breathing, after which death will come from suffocation for some time. The current of more than 50 mA up to 100 mA at 50 Hz is still faster disrupts the work of the lungs and hearts. However, in this case, as at lower currents, light and then heart are affected by the first time.

The alternating current from 100 mA to 5 A at a frequency of 50 Hz and constant from 300 mA to 5 A act directly to the muscle of the heart, which is very dangerous for life, because after 1-2C from the moment of closing the circuit of this current through a person, fibrillation may occur. At the same time, blood circulation ceases and the organism arises a lack of oxygen, which, in turn, leads to the cessation of breathing, that is, death comes. These currents are called fibrillation, and the smallest of them is a threshold fibrillation current.

The current is more than 5 A, as a rule, the heart fibrillation does not cause. With such currents occurs immediate stopping heart, bypassing the state of fibrillation, as well as palsy of breathing. If the current effect was short-term (up to 1-2 ° C) and did not cause damage to the heart (as a result of heating, burn, etc.), then after turning off the current, the heart, as a rule, resumes normal operation. Breathing about this independently is not restored and immediate assistance is required by the victim in the form of artificial respiration.

The duration of the current through the living organism significantly affects the outcome of the lesion: the longer the current effect, the greater the likelihood of severe damage or death. This dependence is due to the fact that with an increase in the time of exposure to the current on the living tissue, the magnitude of this current increases, the likelihood of coincidence of the moment of passage through the heart with a vulnerable phase of the heart cycle (0.2C) increases.

The path of the current in the body of the victim plays a significant role in the outcome of the defeat. If there are vital organs - the heart, the respiratory organs, the brain, the danger of the lesion is very large, since the current affects these organs directly. When the current passes by other ways, the impact on vital organs can only be reflex, thanks to which the probability of hard lesion decreases sharply. Since the skin resistance in different parts of the body is different, then the effect of the current path on the outcome of the damage depends on the place of the application of the current paths to the body of the victim.

Possible streams in the human body are very many; The most common are the following: right hand - legs, left hand - legs, hand - hand and leg - leg. The danger of this or that path of the current can be assessed by the severity of the lesion, as well as the value of the current flowing through the heart, at a given loop.

It is known that the value of the current passing through the human heart (as a percentage of the total current passing through the body) is at the right hand - legs - 6.7%; Left hand - legs - 3.7%; hand - hand - 3.3%; Leg - foot - 0.4%.

Thus, the most dangerous path is the right hand - legs, and the least dangerous - the path of the leg is leg.

Permanent current, as practice shows, about 4-5 times safer than an alternating current of industrial frequency (50 Hz). However, this is true for relatively small stresses - up to 250-300 V. At higher voltages, the danger of DC increases.

Individual properties of man Play a prominent role in the outcome of the defeat. It has been established that healthy and physically strong people are easier to carry electrical strikes than patients and weak. Employed electric current susceptibility has persons suffering from diseases, primarily diseases of the skin, cardiovascular system, internal secretion organs, light, nervous diseases, etc.

2. Conditions and reasonsunder which there is a shock

Causes of electric shock:

§ Touching to current-generating parts, bare wires, electrical appliances contacts, switches, lamp cartridges, fuses under voltage;

§ Touching the parts of electrical equipment, metal structures of structures, etc., in the usual state of not located, but as a result of damage (breakdown) of isolations of the insulated substitution:

§ Finding near the place of connection with the land of the torn wire of the power supply;

§ Finding in the immediate vicinity of current-carrying parts under voltage above 1000 V;

§ Touching to the current-carrying part and a wet wall or metal structure connected to the ground;

§ Simultaneous touch to two wires or other current parts that are under voltage;

§ Uncoordinated and erroneous actions of personnel (voltage supply to the installation, where people work; leaving the installation under voltage without supervision; admission to work on the disabled electrical equipment without checking the absence of voltage, etc.).

The person falls under the effect of electric current with a random touch to the current-generating parts of the electrical installation or approximation to an unacceptably close distance, when an emergency mode occurs in the electrical installation; If the electrical installation parameters are inconsistent with the standards, as well as in violating the safety and operation of electrical installations.

Table 1. Statistical data on the causes of people

Cause of lesion	% of all electricians
Touching open current-duct units
Touching the conductive parts of the equipment that was under voltage as a result of insulation damage
Touching the current-handing parts covered with isolation that has lost their properties; Touching current parts with low electrical resistance
Contact with floors, walls, elements of structures, soil, which caused by stress due to emergency closure on the ground
Electric arc

factor Defection Electric Current

When considering the conditions for the occurrence of the electrical circuit through a person's body, a direct contact of a person with current-friendly parts and indirect is distinguished. Direct contact arises, as a rule, as a result of the violation of the safety and operation of electrical installations, and the indirect - when testing isolation on the equipment body.

Circuit on the housing is a random electrical connection of the current-carrying part with metal inadvertent parts of the electrical installation. Grinding to Earth is a random electrical connection of a current-carrying part with earth or inappropriate conductive designs or objects, not isolated from the ground.

The current through the human body passes in the case when a person simultaneously concerns two points, between which there is a voltage. The magnitude of the striking current depends on which parts of the electrical installation concerns the person, that is, from the conditions of the defeat.

The following lesion conditions may be observed:

bipolar touch to the current parts

With a bipolar touch to the current-carrying parts, the person simultaneously concerns parts of the body (for example, by hand) of current-carrying parts of the equipment.

single-pole touch to the current parts

The circuit of the current through the human body in the network with an isolated neutral closes through the ground and conductivity, existing between the network and earth phases. On the network with ground neutral, the current closes through a person, the land and grounding neutral. Thus, with a single-pole touch, one of the point of touch is the point of the soil (land).

touching groundless inadvertent parts

When touched to grounded equipment, which produced under voltage, the person is in the zone of the current specimen, that is, in the zone, each point of which has a certain electrical potential, due to the course of the earth circuit current.

touch voltage

In all cases, human lesions with current voltage is applied to the entire chain of the person, which includes resistance: body, shoes, floor or soil on which a person stands, etc. This part of the voltage, which falls in this chain to the human body, is called the tension of the touch.

effect of stress step

If a person is near the grounding agent, from which the current flows into the ground or near the place of random closure to the Earth, then some of this current can be branched and pass through the legs of a person. The potential difference between the feet feet at a step of the step in the zone of the current is called a stepper voltage. The voltage of the step is defined as the voltage between the two points of the soil in the zone of the current specimen, which are one of the other at a distance of the step, which simultaneously relieve the feet of the walking person. The stepper voltage is the greater, the closer to the earthingant there is a person and the larger the length of his step. From here, measures are apparent to prevent the defeat by step voltage - the elimination of people's stay in the spreading zone and removal of a person from the zone in which the dangerous potential arose, small steps.

3. Electrical Safety Measuresin production

3.1 Organizational protection measures

Instrupture

The purpose of the briefing is a message to the knowledge workers necessary for the correct and safe fulfillment by them their professional duties.

The following types are distinguished.

induction training

primary instruction

periodic (repeated).

Safety technique

Safety technique - This is a system of technical means and techniques to ensure the safety of working conditions. This is one of the most important events in the field of labor protection.

Proper workplace organization

The workplace is the zone of the employment of a certain employee or a group of workers (brigades).

Labor and recreation

The optimal mode of work and recreation is such an alternation of periods of working with recreation periods, in which the greatest efficiency of human activity and good condition of his health is achieved.

The optimal mode of work and recreation is achieved:

pauses in work and breaks;

shift forms of work and environmental conditions;

maintaining a certain tempo and rhythm of work;

elimination of monotony and low-speed;

removing neuropsychic loads with rest in the recreation rooms;

using the psychological effects of color, music and technical aesthetics.

Application of personal protective equipment

Individual protective equipment are designed to protect the body, respiratory organs, vision, hearing, head, face and hands from injuries and exposure to adverse production factors.

Electrical protection products are divided into basic and extra ..

Maintenance Electroplature tools to work in electrical installations with voltage above 1 kV.: Insulating rods, insulating and electrical testers, voltage pointers.

Additional: dielectric gloves, bots, carpets and caps; Individual screening sets, insulating stands and lining; portable grounding; fender devices; Posters and safety signs.

Main electric equipment To work in electrical installations with voltage up to 1 square: Insulating rods, insulating and electro-measuring ticks, voltage pointers, dielectric gloves, fitting and assembly tool with insulating handles.

Additional: Dielectric galoshes and carpets, portable grounding, insulating stands and lining, fenced devices, posters and safety signs.

The use of warning posters and safety signs

When working in electrical installations, there is a danger of loss of orientation by working.

Recruitment

Safety regulations provide selection for the health of staff for servicing existing electrical installations.

3.2 Organizational and technical protection measures

Insulating and fencing of current-handing parts of electrical equipment

To eliminate the possibility of touching or dangerous approximation to uninsulated current parts, the latter may be ensured by the latter by the fencing or location of the current-carrying parts in an inaccessible height or in an inaccessible place.

Application blocking

Locks are used to ensure unavailable current-carrying parts. They are used in electrical installations, in which work is often produced on protective current-carrying parts (test stands, installations for testing isolation with high voltage, etc.).

Portable earthing

These are temporary entries that are designed to protect against the shock of the personnel current producing work on the disconnected current parts of the electrical installation, with the accidental appearance of the voltage in these parts.

Protective insulation

W Working - electrical insulation of current-carrying parts of the electrical installation, providing its normal operation and protection against electric shock;

W Additional - electrical insulation provided for in addition to working isolation to protect against electric shock in case of damage to the working isolation;

W Double - electrical insulation consisting of working and additional isolation.

Isolated workplace.

Conclusion

Perhaps there is no such professional activity, where the electric current would not be used. Even the teacher often resorts to electrical appliances (tape recorder, projector, lighting lamps) - what to say about other professions.

In addition, it should be noted a serious danger to human health, which is an electric current. Its impact on the body, which is a conductor with a resistance of about 1000 ohms, is manifested in contact (often random) any part of its body with components of the electrical circuit. This effect is directly dependent on the characteristics of the current (force and voltage) in the chain, as well as on the physical and neuropsychic state of the person.

With electrical impact, we can talk about the severity of the affecting current: a safe release, irritant, irritable and deadly currents.

In addition to touching the current parts of the equipment or bare wires, the cause of electric shock can be the so-called step voltage.

The most terrible effect of electric shock is death. Fortunately, it happens in this case quite rarely.

To prevent electroporation and supply of electrical safety in production: insulation of wires and other components of electrical chains, devices and machines; protective grounding; rejection, emergency voltage disconnection; Individual means of protection and some other measures.

Unfortunately, the widespread aging of production assets, the winding of the premises adversely affects the quality of wiring. Slobs in the electrical wiring lead not only to shocks current, but are one of the main causes of fires.

List of used literature

1. V.E. Anofrices, S.A. Bobok, M.N. Dudko, GD. Elistratov Safety of vital activity: studies. Address for universities, GUU. Moscow, CJSC "Finstatinform", 1999. 156st.

2. Ed. B.A. Knyazevsky labor protection. Moscow, "Higher School", 1972., 67st.

3. V.I.rusin, G.G. Eorlov, N.M.Norako and others. Labor protection in construction. Engineering solutions: Directory, Kiev, "Budivaelk", 1990, 45passed.

4. Ed. B.A. Knyazevsky labor protection in Energy, Moscow, Energoatomizdat, 1985, 200lt.

5. Under total. ed. I.S. Ivanov Countries of the World: Directory, Moscow, Republic, 1999, 143 pp.

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The main factors determining the affecting effect of electric current. Factors determining the outcome of electric shock

Electricity

Factors determining the outcome of electric shock

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