Issues of electrical safety in production are only part of all activities and industrial safety requirements. Compliance with the requirements of numerous instructions and rules, ensuring safe working conditions is entrusted to the employer by the Labor Code of the Russian Federation. He is also responsible. Its extent depends on the severity of the consequences of violations or failure to comply with industrial safety and labor protection requirements. The head of an enterprise, especially if it is large, appoints employees responsible for compliance with occupational safety, fire and electrical safety requirements.
Regulations
The Rules for the Construction of Electrical Installations (PUE) apply to all electrical installations under construction and reconstruction of alternating and direct current with a voltage of 750 kV and are mandatory, regardless of industry affiliation and form of ownership. The new, 7th edition is constantly updated as materials are processed and agreed upon with interested departments and approved by the ministry.
Nevertheless, experts argue that the publication does not cover the entire scope of the necessary changes, and probably in the near future the next updated edition of the PUE will be published.
Labor protection and fire safety requirements when working with electrical installations are also changing.
Categories of premises for electrical safety, PUE
In accordance with the rules of design, an electrical installation is a set of technological electrical equipment of machines and devices, together with the structures in which they are installed, intended for generation or transmission, transformation and redistribution, conversion into other types of energy. Are divided into:
- External (open). Located in open areas not protected from weather influences.
- Closed (internal). Located in buildings that protect them from atmospheric influences.
Electrical rooms are various structures, buildings or fenced off parts of the premises in which electrical equipment is located with access only to qualified personnel engaged in maintenance. All these electrical safety premises are divided into 4 categories:
- Premises without increased danger.
- Premises with increased danger.
- Particularly dangerous.
- Territories where open electrical installations are installed, where people can be electrocuted, are considered particularly dangerous areas.
1 category
The PUE states that these are premises in which there are no conditions for increased or special danger. What kind of premises are these?
Premises without increased danger are ordinary residential or office buildings. Social enterprises: preschool institutions, schools, hospitals and so on. Basic requirements for category 1:
- Dry - 60% and wet rooms where air humidity should not exceed 75%.
- Working supply and exhaust ventilation. There should be no conductive dust or chemical compounds in the air.
- The ambient temperature does not exceed +35°C.
- The floor covering must be made of non-electrically conductive materials.
Some production facilities and workshops can also be included in this category, but the above conditions must be met. Occupational safety requirements for employees are limited to introductory briefings and on-the-job briefings twice a year.
Specialists with the 3rd tolerance group up to 1000 volts are allowed to service electrical installations. The person responsible for electrical equipment is appointed from the engineering staff with the 4th group.
Category 2: hazardous premises for electrical safety
The current classification of premises according to the electrical safety of the Electrical Installation Code (PUE) includes those that meet the following criteria in the second category:
- Damp rooms. Humidity more than 75%
- There may be conductive dust in the air.
- Workshops with high levels of chemical compounds in the air.
- The floors are made of materials capable of conducting electricity (metal, earth, reinforced concrete, brick, etc.).
- Rooms with high temperatures.
- The ability to simultaneously touch a machine or other equipment on one side and metal parts (cases) of electrical equipment or exposed conductive parts on the other.
The list of enterprises and workshops that fall into this category is very large. Almost all enterprises, with the exception of especially dangerous ones, fall into this category.
It is mandatory to carry out occupational health and safety measures. In specialties related to work in hazardous and hazardous industries, additional training is provided with certification and admission of workers. Certification of workplaces is carried out.
At enterprises, it is mandatory to carry out an electrical inspection of the premises for electrical safety. Based on the findings of the examination, a category is assigned and a special sign (plate) is posted at the entrance, which indicates the electrical safety class of the room.
Only qualified specialists who have undergone training and have a clearance group in accordance with labor protection requirements when servicing electrical installations are allowed to perform maintenance.
Category 3: especially dangerous premises for electrical safety
Particularly dangerous electrical safety premises include those in which there is at least one of the following factors:
- Particularly raw. Air humidity 100%. Walls and equipment become covered with moisture that falls in the form of condensation.
- Premises with an active chemical or organic environment that occurs in the room during the work shift. This environment destroys electrical installation parts and wire insulation.
- If two factors related to high-risk conditions occur simultaneously.
This category of electrical safety premises has special requirements for the equipment and materials used. More frequent maintenance and repairs are provided. Only qualified personnel trained to work in certain conditions work. Labor protection, as a rule, classifies such production as hazardous.
Category 4: territories where open electrical installations are installed
The category of especially dangerous includes outdoor switchgear - open switchgear. Transformer substations, distribution centers consisting of a huge amount of electrical equipment. Located in an open area and surrounded by a fence. These are areas closed to unauthorized entry, where special industry requirements for labor protection and worker qualifications apply.
All premises certified for electrical safety must be marked with signs informing workers and representatives of regulatory authorities about the category of danger behind the doors.
Rules for electrical installations
7th edition
Section 1
General rules
Chapter 1.1 General part
Approved by order of the Ministry of Energy of the Russian Federation dated 07/08/02 No. 204. Entered into force on 01/01/03. Prepared by JSC "VNIIE"
Application area. Definitions
1.1.1.
Rules for the construction of electrical installations (PUE) apply to newly constructed and reconstructed electrical installations of direct and alternating current with voltage up to 750 kV, including special electrical installations discussed in section. 7 of these Rules.
Construction of special electrical installations not discussed in Section. 7 must be regulated by other regulatory documents. Separate requirements of these Rules may be applied to such electrical installations to the extent that they are similar in design and operating conditions to the electrical installations discussed in these Rules.
The requirements of these Rules are recommended to be applied to existing electrical installations if this increases the reliability of the electrical installation or if its modernization is aimed at ensuring safety requirements.
In relation to reconstructed electrical installations, the requirements of these Rules apply only to the reconstructed part of the electrical installations.
1.1.2.
PUEs are developed taking into account the mandatory conduct of scheduled preventative and maintenance tests, repairs of electrical installations and their electrical equipment under operating conditions.
1.1.3.
An electrical installation is a set of machines, apparatus, lines and auxiliary equipment (together with the structures and premises in which they are installed) intended for the production, transformation, transformation, transmission, distribution of electrical energy and its conversion into other types of energy.
1.1.4.
Open or outdoor electrical installations are electrical installations that are not protected by the building from atmospheric influences.
Electrical installations protected only by canopies, mesh fences, etc. are considered external.
Closed or internal electrical installations are electrical installations located inside a building that protects them from atmospheric influences.
1.1.5.
Electrical rooms are rooms or fenced off (for example, nets) parts of the room in which electrical equipment is located, accessible only to qualified service personnel.
1.1.6.
Dry rooms are rooms in which the relative air humidity does not exceed 60%.
If the conditions specified in 1.1.10-1.1.12 are absent in such premises, they are called normal.
1.1.7.
Wet rooms are rooms in which the relative air humidity is more than 60%, but does not exceed 75%.
1.1.8.
Damp rooms are rooms in which the relative air humidity exceeds 75%.
1.1.9.
Particularly damp rooms are rooms in which the relative air humidity is close to 100% (the ceiling, walls, floor and objects in the room are covered with moisture).
1.1.10.
Hot rooms are rooms in which, under the influence of various thermal radiation, the temperature constantly or periodically (more than 1 day) exceeds +35 ° C (for example, rooms with dryers, kilns, boiler rooms).
1.1.11.
Dusty rooms are rooms in which, due to production conditions, process dust is released, which can settle on live parts and penetrate into machines, devices, etc.
Dusty rooms are divided into rooms with conductive dust and rooms with non-conductive dust.
1.1.12.
Rooms with a chemically active or organic environment are rooms in which aggressive vapors, gases, liquids are constantly or for a long time contained, deposits or mold are formed that destroy the insulation and live parts of electrical equipment.
1.1.13.
With regard to the danger of electric shock to people, the following are distinguished:
1) premises without increased danger, in which there are no conditions that create increased or special danger (see paragraphs 2 and 3);
2) premises with increased danger, characterized by the presence of one of the following conditions creating increased danger:
dampness or conductive dust (see 1.1.8 and 1.1.11);
conductive floors (metal, earthen, reinforced concrete, brick, etc.);
high temperature (see 1.1.10);
the possibility of simultaneous human contact with metal structures of buildings connected to the ground, technological devices, mechanisms, etc., on the one hand, and with metal casings of electrical equipment (exposed conductive parts), on the other;
3) especially dangerous premises, characterized by the presence of one of the following conditions creating a special danger:
special dampness (see 1.1.9);
chemically active or organic medium (see 1.1.12);
simultaneously two or more conditions of increased danger (see 1.1.13, paragraph 2);
4) the territory of open electrical installations in relation to the danger of electric shock to people is equated to especially dangerous premises.
1.1.14.
Qualified service personnel are specially trained workers who have passed a knowledge test to the extent required for this job (position), and have an electrical safety group provided for by the current labor protection rules when operating electrical installations.
1.1.15.
The nominal value of a parameter is the value of a parameter of an electrical device specified by the manufacturer.
1.1.16.
AC voltage is the effective value of voltage.
DC voltage - direct current voltage or rectified current voltage with a ripple content of no more than 10% of the effective value.
1.1.17.
To indicate the mandatory compliance with the requirements of the PUE, the words “must”, “should”, “necessary” and derivatives from them are used. The words “as a rule” mean that this requirement is predominant, and deviation from it must be justified. The word “allowed” means that this decision is applied as an exception as forced (due to cramped conditions, limited resources of necessary equipment, materials, etc.). The word “recommended” means that this solution is one of the best, but not required. The word “may” means that the decision is lawful.
1.1.18.
The standardized values of quantities accepted in the PUE with the indication “not less” are the smallest, and those with the indication “no more” are the greatest.
All values of quantities given in the Rules with the prepositions “from” and “to” should be understood as “inclusive”.
Chapter 1.1 General instructions for electrical installations
General instructions for electrical installations
1.1.19.
Electrical equipment, electrical products and materials used in electrical installations must comply with the requirements of state standards or technical specifications approved in the prescribed manner.
1.1.20.
The design, design, installation method, class and insulation characteristics of the machines, devices, instruments and other electrical equipment used, as well as cables and wires, must comply with the parameters of the network or electrical installation, operating modes, environmental conditions and the requirements of the relevant chapters of the PUE.
1.1.21.
Electrical installations and associated structures must be resistant to or protected from environmental influences.
1.1.22.
The construction and sanitary parts of electrical installations (the design of the building and its elements, heating, ventilation, water supply, etc.) must be carried out in accordance with the current building codes and regulations (SNiP) with the obligatory fulfillment of additional requirements given in the PUE.
1.1.23.
Electrical installations must meet the requirements of current regulatory documents on environmental protection regarding permissible levels of noise, vibration, electric and magnetic field strengths, and electromagnetic compatibility.
1.1.24.
To protect against the influence of electrical installations, measures must be taken in accordance with the requirements of the standards for permissible industrial radio interference and the rules for protecting communication devices, railway signaling and telemechanics from the dangerous and interfering influence of power lines.
1.1.25.
Electrical installations must provide for the collection and disposal of waste: chemicals, oil, garbage, process water, etc. In accordance with current environmental protection requirements, the possibility of the specified waste entering water bodies, storm water drainage systems, ravines, as well as areas not intended for storing such waste must be excluded.
1.1.26.
The design and selection of circuits, layouts and structures of electrical installations should be made on the basis of technical and economic comparisons of options, taking into account the requirements for ensuring the safety of service, the use of reliable schemes, the introduction of new equipment, energy and resource-saving technologies, and operating experience.
1.1.27.
If there is a risk of electrical corrosion or soil corrosion, appropriate measures must be taken to protect structures, equipment, pipelines and other underground communications.
1.1.28.
In electrical installations, it must be possible to easily recognize parts belonging to individual elements (simplicity and clarity of diagrams, proper arrangement of electrical equipment, inscriptions, markings, colors).
1.1.29.
For color and digital designation of individual insulated or non-insulated conductors, colors and numbers must be used in accordance with GOST R 50462 “Identification of conductors by colors or digital designations”.
Protective grounding conductors in all electrical installations, as well as neutral protective conductors in electrical installations with voltages up to 1 kV with a solidly grounded neutral, incl. tires must have the letter PE
and color designation by alternating longitudinal or transverse stripes of the same width (for tires from 15 to 100 mm) of yellow and green.
Zero working (neutral) conductors are designated by the letter N
and blue color.
Combined neutral protective and neutral working conductors must have the letter designation PEN
and a color designation: blue along the entire length and yellow-green stripes at the ends.
1.1.30.
The alphanumeric and color designations of tires of the same name in each electrical installation must be the same.
Tires must be marked:
1) with alternating three-phase current: phase A buses -
yellow, phase
B -
green, phase
C -
red;
2) with single-phase alternating current, bus B,
connected to the end of the power source winding, in red; bus
A,
connected to the beginning of the power source winding, in yellow.
Single-phase current buses, if they are a branch from the buses of a three-phase system, are designated as the corresponding three-phase current buses;
3) at constant current: positive bus (+) - red, negative (-) - blue and zero operating M
- blue color.
The color coding must be carried out along the entire length of the tires if it is also provided for more intensive cooling or anti-corrosion protection.
It is allowed to carry out a color designation not along the entire length of the busbars, only a color or only an alphanumeric designation, or a color in combination with an alphanumeric designation at the points where the busbars are connected. If non-insulated busbars are not accessible for inspection during the period when they are energized, then they may not be marked. At the same time, the level of safety and visibility when servicing the electrical installation should not be reduced.
1.1.31.
When busbars are located “flat” or “edge-on” in switchgears (except for complete prefabricated single-sided service cells (KSO) and complete switchgears (SGD) 6-10 kV, as well as factory-made panels 0.4-0.69 kV) The following conditions must be met:
1. In switchgears with a voltage of 6-220 kV with alternating three-phase current, prefabricated and bypass busbars, as well as all types of sectional busbars, should be located:
a) in a horizontal position:
one below the other: from top to bottom A-B-C;
one after the other, obliquely or in a triangle: the most distant bus A,
middle
- B,
closest to the service corridor -
C
;
b) with a vertical arrangement (in one plane or in a triangle):
from left to right A-B-C
or the most distant bus
A
, the middle one -
B,
the closest to the service corridor -
C
;
c) branches from busbars, if you look at the busbars from the service corridor (if there are three corridors - from the central one):
when positioned horizontally: from left to right A-B-C
;
with a vertical arrangement (in one plane or in a triangle): from top to bottom A-B-C.
2. In five- and four-wire three-phase alternating current circuits in electrical installations with voltages up to 1 kV, the arrangement of busbars should be as follows:
when positioned horizontally:
one below the other: from top to bottom A- B- C- N- PE ( PEN);
one after another: the most distant bus A,
then phases
B- C- N,
closest to the service corridor -
PE ( PEN);
when positioned vertically: from left to right A- B- C- N- PE ( PEN)
or the most distant bus
A,
then phases
B- C- N,
closest to the service corridor -
PE ( PEN);
branches from busbars, if you look at the busbars from the service corridor:
when positioned horizontally: from left to right A- B- C- N- PE ( PEN);
with vertical position: A- B- C- N- PE ( PEN)
top down.
3. With direct current, the buses should be located:
busbars with vertical arrangement: upper M,
middle (-), bottom (+);
busbars with a horizontal arrangement: the most distant M,
middle (-) and closest (+), when looking at the tires from the service corridor;
branches from busbars: left busbar M,
middle (-), right (+), when looking at the tires from the service corridor.
In some cases, deviations from the requirements given in paragraphs are allowed. 1-3, if their implementation is associated with a significant complication of electrical installations (for example, it necessitates the installation of special supports near the substation for the transposition of overhead power line wires) or if two or more transformation stages are used at the substation.
1.1.32.
Electrical installations, according to electrical safety conditions, are divided into electrical installations with voltage up to 1 kV and electrical installations with voltage above 1 kV (according to the effective voltage value).
The safety of operating personnel and unauthorized persons must be ensured by implementing the protective measures provided for in Chapter. 1.7, as well as the following activities:
maintaining appropriate distances to live parts or by closing or fencing live parts;
use of device locking and fencing devices to prevent erroneous operations and access to live parts;
use of warning alarms, signs and posters;
the use of devices to reduce the strength of electric and magnetic fields to acceptable values;
the use of protective equipment and devices, including for protection from the effects of electric and magnetic fields in electrical installations in which their intensity exceeds permissible standards.
1.1.33.
In electrical premises with installations with voltages up to 1 kV, the use of non-insulated and insulated live parts without contact protection is allowed, if, according to local conditions, such protection is not necessary for any other purposes (for example, for protection from mechanical influences). In this case, parts accessible to touch must be located so that normal maintenance does not involve the danger of touching them.
1.1.34.
In residential, public and other premises, devices for fencing and closing live parts must be solid; in rooms accessible only to qualified personnel, these devices can be solid, mesh or perforated.
Fencing and closing devices must be made in such a way that they can only be removed or opened using keys or tools.
1.1.35.
All enclosing and closing devices must have the required (depending on local conditions) mechanical strength. At voltages above 1 kV, the thickness of metal enclosing and closing devices must be at least 1 mm.
1.1.36.
To protect service personnel from electric shock, electric arc, etc. all electrical installations must be equipped with protective equipment, as well as first aid equipment in accordance with the current rules for the use and testing of protective equipment used in electrical installations.
1.1.37.
Fire and explosion safety of electrical installations must be ensured by meeting the requirements given in the relevant chapters of these Rules.
Upon commissioning, electrical installations must be equipped with fire-fighting equipment and equipment in accordance with current regulations.
1.1.38.
Newly constructed and reconstructed electrical installations and electrical equipment installed in them must be subjected to acceptance tests.
1.1.39.
Newly constructed and reconstructed electrical installations are put into commercial operation only after they have been accepted in accordance with the current regulations.
