An accident in the train power supply system. OBZhD

BASICS OF SAFE LIFE
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An accident in the train power supply system. Basics of safe life

Fundamentals of Safe Life Activities (OBZhD)

The electrical equipment of passenger cars operates in a wide voltage range: from 50 V DC to 300 V DC or AC. In the system of high-voltage electrical equipment of cars, the current can reach tens and hundreds of amperes. Electric current even with a power of 0,05 A, passing through the human body, causes serious consequences, manifested in the form of burns, tissue damage, severe muscle contraction, etc.

A current of 0,1 A with a conventionally accepted surface resistance of the human body of 1000 ohms inflicts an electric shock that affects the entire body, and therefore is deadly. The outcome of an electric shock is affected by the strength and path of the current that has passed through the human body; the duration of the current, its frequency; environment (humidity, floor conductivity, etc.), individual properties and the state of the body.

The question of the so-called step voltage, which is created by the current spreading along the ground, is very important. The potential difference formed in this case between the two points of contact of the feet on the surface of the earth is the step voltage. The spreading of current along the ground depends on the resistivity of the soil: wet soils reduce resistance and are more dangerous. Step voltages can occur when a broken wire contact touches the ground when the voltage is not removed from it. The step voltage zone extends for a distance of 2 m around the circumference if a broken contact wire touches the ground in dry weather, and 20-30 m in wet weather.

In case of getting into a stress zone, it is necessary to leave it as soon as possible. For safety reasons, it is necessary to connect the soles of the feet and, slowly, leave the danger zone, moving no more than the width of the foot or jump.

In the event of a break in the contact network or another wire, these wires must not be touched - regardless of whether these wires lie on the ground or only touch grounded parts of the body.

Do not remove objects lying on fallen wires. It is forbidden to carry out any work near the fallen wires. Having found fallen or damaged wires, it is necessary to notify the mechanic-foreman about this as soon as possible when the train is moving or the person on duty at the depot, park, station when the car is in the parking lot.

Providing first aid in case of electrical injury. First of all, it is necessary to free the victim from the action of electric current. Touching live parts that are energized causes in most cases an involuntary convulsive contraction of the muscles. Because of this, the fingers, if the victim holds the wire in his hands, are compressed so much that it is impossible to release the wire from his hands. This must be done very carefully, in compliance with safety rules, so as not to "connect" to the electrical circuit and not be exposed to current.

It is better, if possible, to turn off the breaker or switch. If they malfunction, you should cut or bite the electrical wires with wire cutters, but be sure to each one individually to avoid a short circuit. It must be remembered that without proper precautions, touching a person who is energized is life threatening. The first action should be to quickly disconnect from the network that part of the equipment that the victim touches.

When the unit is turned off, the electric light may go out, so it is necessary to take care of other sources of lighting (lanterns), while not delaying the shutdown of the equipment and rendering assistance to the victim.

If the shutdown of the electrical installation cannot be carried out quickly enough, measures must be taken to separate the victim from the current-carrying parts that he touches. To separate the victim from the wire, use some kind of dry insulator (clothing, rope, stick, board). Do not use metal and wet objects in such cases. You can also take on the parts of his clothes that are lagging behind the body if it is dry (for example, the floors of a coat). At the same time, one should avoid touching the surrounding metal objects and parts of the victim's body that are not covered with clothing. You should also not pull the victim by the legs without first isolating his hands, since his shoes may be wet, and the nails or lacing hooks in them are current conductors.

To isolate the hands, especially if it will be necessary to touch the victim in places not covered by clothing, wrap the hands with a scarf, put on a cloth cap, take and lower the sleeves, or throw rubber, rubberized material (cloak) or simply dry, non-conductive material over the victim. bedding, clothes, etc.

It is recommended to use only one hand if possible. Often the victim squeezes the wire; in this case, you should separate the victim from the ground (put a dry board under him, pull his legs off the ground with a rope or clothes), rather than try to unclench his hand. However, even here it is necessary to observe the previously indicated precautionary measures in relation to both oneself and the victim. If necessary, it is necessary to cut or cut the wires with a dry wooden handle ax or a suitable insulating tool. After release from the current, the victim must be given first aid.

Authors: Aizman R.I., Krivoshchekov S.G.

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