PROTECTIVE PROTECTION AGAINST ELECTRIC SHOCK DURING REPAIR OF ELECTRICAL NETWORKS

Affiliation. Students of Electrical engineering, Ferghana Polytechnic Institute

In the case of open space electrical equipment under the influence of the electric field and performing works on power transmission lines of 220 kV and above, the time of the employee's stay in this area should be limited.

In the case of an electric field with a voltage of up to 5 kV / m, the time of the workers stay there is not limited. If the electric field is in areas with a voltage of 20 to 25 kV/m, the presence of workers there should not exceed 10 minutes. Protective equipment should be used when the electric field voltage exceeds 25 kV/m. In this case, the working time is limited to one working day.

T clock, where the electric field intensity is in the range from 5 to 20 kv/m, is calculated with the following formula:

Here is the power amplitude of the electric field in the e-control, kV/m. With the formula in the yaw, when the electric field is fully discharged to the personnel, the standby time is 180 minutes, while the power level is 10 kV/m and 80 minutes when the power is up to 15 kV/m.

During the day, workers can be used once or for all. They may use protective equipment during the working hours or have an electric field with a voltage less than 5 kV/m.

The strength of the electric field and the area of its exposure and its shielding are determined by the measurement results. When performing all work, it is important to measure the power level of the measuring line at the outside of the workplace, where people can measure the entire area.

Measuring acceleration in the work without the removal of equipment and structures is as follows: - in the absence of means of protection - at a height of 1.8 meters above the ground; when using general protection means 0.5 out of the earth; It should be measured at a height of 1.0 and 1.8 meters.

Measuring at works and designs (irrespective of the availability of protective equipment) at the workplace is at least 0.5; At a distance of 1.0 m and 1.8 m, and at a distance of 0.5 m from the cradle attached to the ground. The probability of being in the control area is determined by the maximum value of field strength.

As protection, the following may be used: robust embedded portable and copiic shielding equipment; shielding equipment, mounted on machines and mechanisms; shielding packages. It is not required to use the protection facilities at the cabins and booths, mechanisms, transponders and laboratories connected to the ground, as well as in bricks made of iron-concrete or metal-fired iron-concrete pavement.

Mobile and copper screening devices must be grounded on land-mounted devices or on metal frameworks attached to them through a soft copper wire, at least 10 mm2 of the transverse cutting surface. The shielding equipment mounted on the machine and the machine must be connected to them individually.

When mounting on the ground, the machine and mechanisms do not need to be mounted on the additional shielding equipment. Connecting separate individual display sets to the ground should be done in special footwear. In cases where the insulation is to be made (painted metal, insulator, wooden boom, etc.) or in the case of openings (without gloves) attached to the ground, the shielding gear shall be fitted with a soft copper wire to ground connection equipment having an additional cross-sectional surface of 10 mm2 or connected to the metal constructions attached to the equipment.

This equipment should be grounded to remove the potential voltage during operation at the disassembled crane sections. It is forbidden to touch the cut-off casing but without the ground. Also, repair facilities and equipment that can be left isolated from the ground should also be grounded.

The wheels of the electric field must be grounded and the machines and mechanisms must be connected to the ground using compressed air. When these vehicles move within the area of the electric field, a chain that links the ground to the chassis or body to connect the potential for the potential for voltage. It is forbidden to put fuel and lubricants in machines and mechanisms within the scope of the electric field. It is important to use the protective equipment regardless of the strength of the electrical field and the duration of the work when the equipment and equipment are to be exposed to the impact of the electric field.

The telescopic minaret and the hydraulic hoist should be fitted with a screwdriver or shielded screen or a shielding kit.

The shielding area should not be used in the design of the open distribution equipment, as well as the protection against the impact of the electric field on rising staircase, which indicates the oil level in the power transformers.

In the case of open circuit electrical equipment and to the workplace, the employee must follow the route developed for that purpose.

Use screenshots

When using a personalized shield, the following requirements must be met:

• Sharing of the elements of the individual shielding kit and their connection to the galvanic connection;
• The use of a personal protective shield that has been used for use after chemical treatment;
• Inaccurate testing results and appearance, and the inability to change the characteristics of the test.

The working time of the individual shielding set is determined by interpolation, based on the ambient temperature, the permitted working time.

Table 1.

Permitted continuous operation of the outdoor temperature shield in the summer

Up to 25

b) the authenticity and duration of the connection of the elements of the personal protective covering elements by the responsible manager;

c) It is forbidden to work in the following cases:

• In case of defects of personal protective packaging elements;
• If connector or push button connector is disconnected;
• Suspicion of divorce or loss of shoes;
• The technical condition of the personal protective shield has not been inspected. The following requirements must be observed when wearing a personal protective shoe worker:
• Direct galvanic connection with cabinet (chairs) with shielding kit when operating under the power of the power line airline. The equal distribution of potential of technological equipment and shielding packages should be ensured;
• Before connecting the worker to the power line, the individual shielding device must be connected to the shaft with the shaft and displacement potential to the technological equipment;
•  The distance between the wire potential and the wire and the shielding kit can be avoided by allowing the spark plugs to emerge;
• Employees with a 220 kV or higher voltage transmission line or shunting trap shall not be less than 1 m wide from the base isolated thunder;
• In the course of work, defective engines, openings or other faults in the contact cards of the individual shielding compartment are detected and the work stop and the worker is grounded, and the defective personal protective shield is replaced with repair or replacement.

Maintenance and repair of the personal protective shield must be carried out as follows:

• Protection from aggressive environment in special cabinets in dry, heated rooms;
• Periodic cleaning of personal protective cover (dry chemical clean-up, washing is prohibited);
• Improvement of appearance of individual shielding components and restoration of electrical conductivity (repair of shielding material for simple materials)

No additional protection devices are required for the workers working on the air transmission line, apart from a personal protective package. Workers on the ground are allowed to work without shielding during the working day and the accuracy and durability of the elements of the shielding elements of workers should be checked by the responsible administrator.

List of references:

1. Михаил Фленов, “Библия Delphi” 2–е издание. Санкт–Петербург “БХВ–Петербург”–2008
2. Е.И.Удод “Ремонт электроустановок под наприжением”–Техника –1986
3. Направляем краткий обзор аварийности на предприятиях ГАК “Узбекэнерго” за 2009 год–ГАК “Узбекэнерго” СНТБ №19–15–20.04.2010
4. Направляем краткий обзор аварийности на предприятиях ГАК “Узбекэнерго” за 2013 год–ГАК “Узбекэнерго” СНТБ №19–15 18.03.2014