What electrical installations are considered operational? Classification of electrical installations by voltage?

Often, even good specialists have problems with theory. For example, the question of what an existing electrical installation is causes confusion for many.

To answer it, you need to study documents for electrical personnel, which provide definitions of concepts and terms. At the same time, theoretical knowledge must be supported by examples of definitions from practice.

1.7.17

When carrying out construction, installation, adjustment and repair work on existing electrical installations of the Consumer, third-party organizations must develop joint measures for labor safety, industrial sanitation, explosion and fire safety, taking into account the interaction of construction, installation and operating personnel. The heads of organizations carrying out this work are responsible for the qualifications of their personnel, their compliance with safety requirements and for organizing and implementing occupational safety measures at their work sites.

When performing work on the same equipment or structure simultaneously by several organizations, a work organization plan must be drawn up.

Purpose ↑

It is difficult to imagine modern life without electrical installations. This applies to everyday life, work, and recreation. It is these devices that are responsible for generating, transforming and redistributing electric current, which is now one of the main energies.

They are simply necessary to ensure the operation of enterprises. Very often the central network is not enough to obtain the necessary power; a huge amount of equipment requires a special approach. Also, many facilities must have a backup power system: for example, in hospitals, even a temporary loss of voltage due to any emergency can lead to death.

Electrical installations are often used to generate electricity using solar, water, air or nuclear energy.

Work permit

The work permit is a task and a tool for authorization, the basis for ensuring electronic security. You will need 2 copies, and when transferring remotely - 3 copies. and at the same time, the issuer fills out 1 copy, and the receiver fills out 2 copies. and writes his full name in place of the signature of the first, certifying the data with his signature. The quantity of the specified organizational instrument for one responsible person is determined by the issuer. You can issue several of them (as well as orders) for sequential execution.

For the document in question there is a special form that defines:

• for work: possible actions, goals, time, safety conditions;
• performers, responsible persons.

Validity and storage periods for outfits:

• up to 15 cal. days from the start date of work;
• extended no more than 1 time per 15 cal. days;
• remains relevant during breaks;
• another employee with the right to issue a document for the used EC has the right to renew;
• store for 30 days. after execution, then destroyed.

Rules for Technical Operation of Consumer Electrical Installations (PTEEP), edition 2003.

Section 1

Organization of operation of electrical installations

Chapter 1.3

ACCEPTANCE FOR OPERATION OF ELECTRICAL INSTALLATIONS

1.3.1. New or reconstructed electrical installations and start-up complexes must be put into operation in the manner set out in these Rules and other regulatory documents.

1.3.2. Before installation or reconstruction of electrical installations, it is necessary to:

obtain technical specifications from the energy supply organization;

complete design documentation;

coordinate the design documentation with the energy supply organization that issued the technical specifications and the state energy supervision body.

1.3.3. Before accepting electrical installations into operation, the following must be carried out:

during the construction and installation of a power facility - intermediate acceptance of equipment units and structures, including hidden work;

acceptance testing of equipment and commissioning tests of individual electrical installation systems;

comprehensive testing of equipment.

1.3.4. Acceptance tests of equipment and commissioning tests of individual systems must be carried out according to design schemes by the contractor (general contractor) with the involvement of the customer’s personnel after completion of all construction and installation work on the electrical installation being delivered, and comprehensive testing must be carried out by the customer.

1.3.5. Before acceptance and commissioning tests and comprehensive testing of equipment, compliance with these Rules, rules for electrical installations, building codes and regulations, state standards, occupational safety rules, explosion and fire safety rules, instructions from manufacturers, and equipment installation instructions must be checked.

1.3.6. To carry out commissioning and testing of electrical equipment, it is allowed to switch on electrical installations according to the design diagram on the basis of a temporary permit issued by the state energy supervision authorities.

1.3.7. During a comprehensive testing of equipment, the operability of the equipment and technological schemes and the safety of their operation must be checked; all monitoring and control systems, protection and interlock devices, alarm devices and instrumentation were checked and configured. Comprehensive testing is considered to be carried out under the condition of normal and continuous operation of the main and auxiliary equipment for 72 hours, and power lines for 24 hours.

1.3.8. Defects and deficiencies made during construction and installation, as well as equipment defects identified during acceptance and commissioning tests, comprehensive testing of electrical installations, must be eliminated. Acceptance for operation of electrical installations with defects and imperfections is not permitted.

1.3.9. Before testing and acceptance, conditions must be prepared for reliable and safe operation of the power facility:

Electrical and electrical engineering personnel are staffed and trained (with knowledge testing);

operational instructions, labor protection instructions and operational schemes, technical documentation for accounting and reporting were developed and approved;

protective equipment, tools, spare parts and materials have been prepared and tested;

communications, alarm and fire extinguishing, emergency lighting and ventilation facilities were put into operation.

1.3.10. Before being allowed into operation, electrical installations must be accepted by the Consumer (customer) in the prescribed manner.

1.3.11. Voltage is supplied to electrical installations only after obtaining permission from the state energy supervision authorities and on the basis of an electricity supply agreement between the Consumer and the energy supply organization.

1.4.12

The head of the Consumer or structural unit may exempt from internship an employee with at least 3 years of experience in his specialty who moves from one workshop to another, if the nature of his work and the type of equipment on which he worked previously does not change.

Admission to the internship is issued by the relevant document of the head of the Consumer or structural unit. The document indicates the calendar dates of the internship and the names of the employees responsible for its implementation.

The duration of the internship is set individually depending on the level of professional education, work experience, and profession (position) of the student.

EFFECT OF ELECTRIC CURRENT ON THE HUMAN BODY

1. Thermal.
   It consists of heating tissues, organs, blood vessels and biological environments of the body, which leads to overheating of the entire organism, and, as a consequence, disruption of metabolic processes and associated abnormalities.
2. Electrolytic.
   It consists of the decomposition of blood, plasma and other physiological solutions of the body with the destruction of their functions.
3. Biological.
   Associated with irritation and excitation of nerve fibers and tissues. It is also associated with irritation and excitation of other tissues of the body, which is accompanied by involuntary convulsive muscle contractions.

1. ^ Electrical injury (local effect)
   . This is a clearly defined local damage to body tissues caused by exposure to electric current or electric arc. This usually involves damage to areas of skin, ligaments and bones. In some cases, electrical injuries result in death.

electrical burn current
arc electric sign skin metallization. electroophthalpy

1. ^ Electric shock (general effect)
   . This is the excitation of living tissues of the body when an electric current passes through them, accompanied by convulsive muscle contractions. Depending on the severity of the damage, electric shocks are divided into 4 degrees:

fibrillation

1. Current strength. It is the main factor determining the degree of damage to a person. To characterize the impact on humans, 3 criteria have been established:

Table 2.

1. Electrical resistance of the human body. The resistance of the human body with dry, clean skin ranges from 3 kOhm to 100 kOhm. In calculations related to electrical safety, the resistance of the human body is taken to be 1 kOhm.
2. Duration of flow through the human body. It has a significant impact on the outcome of the lesion, since over time the level of resistance of the human body drops sharply and damage to vital organs becomes more likely. The longer the electrical current is applied, the greater the likelihood of severe or fatal injury.
3. Type of current. The most dangerous is alternating current with a frequency of 20-1000 Hz and voltage up to 300 V. At higher voltages, direct current is more dangerous.
4. Individual properties of the human body. Healthy and physically strong people can more easily withstand the effects of electric current than sick and weakened people.
5. The path of electrical current through the human body. The most dangerous is the passage of electric current along the axis of the body, as well as through the heart, lungs and brain. The path of current in the victim's body plays a very important role in the outcome of the injury. If vital organs get in the way of the electric current, the likelihood of a serious outcome increases.
6. Environmental conditions. The risk of electric shock and the severity of the consequences increase, for example, in a humid environment, during rain or snowfall.
7. The area of ​​human contact with live parts.

Main types of electrical installations

There are 5 main types of the most common electrical installations:

1. Power plants, equipment intended for industrial purposes. Electrical installations are designed for compressor, ventilation, pumping units and other purposes; they are characterized by constant load currents within the widest range of power values. These installations are characterized by a symmetrical load and evenly distributed across all phases. The reliability category of this type of electrical installation is 1.
2. Installations for converting alternating current into direct current, from frequency, number of phases, voltage values, and for inversion. The reliability category, mainly due to undersupply of energy, classifies electrical installations into category II.
3. Installations for electrothermal operations: arc action, induction, dielectric heating, electron beam and other types of heating. Electrothermal installations of all types, with the exception of arc furnaces, belong to category – 2. Arc furnaces belong to category of power supply reliability – 1.
4. Installations used for electric welding work. The load of this type of installation is uneven and, in terms of power supply reliability, belongs to the 3rd reliability category.
5. Electric lighting installations have a single-phase load. Symmetrical load distribution (unsymmetry from 5 to 10%) is achieved by using low power of electric lighting devices, through uniform distribution across phases.

1.5.36

When switching in electrical installations, the following order must be observed:

the employee who received the switching task is obliged to repeat it, write it down in

operational journal and establish the order according to the operational scheme or layout diagram

upcoming operations; draw up, if necessary, a switching form. Negotiation

operating personnel must be extremely concise and clear. Operative language

must exclude the possibility of staff misunderstanding received messages and transmitted orders. The giver and receiver of the order must clearly understand the order of operations;

if switching is performed by two workers, then the one who received the order is obliged to explain, using the operational connection diagram, to the second worker participating in the switching, the order and sequence of upcoming operations;

if there are any doubts about the correctness of the switching, they should be stopped and the required sequence should be checked according to the operational connection diagram;

After completing the switching task, an entry about this should be made in the operational log.

Related links

• Rules for the technical operation of consumer electrical installations / Regulatory document dated February 9, 2007 at 02:14
• Electrician's Bible / Regulatory document January 14, 2014 at 12:32 pm
• Handbook on electrical networks 0.4-35 kV and 110-1150 kV. Volume 10 / Regulatory document from March 2, 2009 at 18:12
• Kabyshev A.V., Tarasov E.V. Low-voltage circuit breakers / Regulatory document dated October 1, 2022 at 09:22
• Rules for the installation of overhead power lines with voltage up to 1 kV with self-supporting insulated wires / Regulatory document dated April 30, 2008 at 15:00
• Knyazevsky B.A. Trunkovsky L.E. Installation and operation of industrial electrical installations / Regulatory document dated October 17, 2019 at 12:36
• Mankov V.D. Zagranichny S.F. Protective grounding and grounding of electrical installations / Regulatory document dated March 27, 2022 at 09:05

Electrical equipment classes

Electrical equipment has always been divided into classes, the main of which are ways to protect people from electric shock:

1. Class zero deals only with minimal insulation. It provides air gaps.
2. The first class is connected to the electricity network with three-core cables. It acts as a means of communication with the protective conductor.
3. The second class provides protection and enhances insulation through grounding. This doubles your overall protection.
4. The third class deals with electrical power from low voltage and its various sources.

For a safe and productive process of interaction with devices, circuits, devices and reasonable energy consumption, basic knowledge will certainly help and rescue in case of problems and malfunctions.

1.5.1

The Electrical Energy Consumer's electrical management system is an integral part of the energy management system, integrated into the Consumer's management system as a whole, and must provide:

operational development of the Consumer's power supply scheme to meet his electricity needs;

efficient operation of electrical facilities by improving energy production and implementing energy saving measures;

increasing the reliability, safety and trouble-free operation of equipment; renewal of fixed production assets through technical re-equipment and reconstruction of electrical equipment, modernization of equipment;

introduction and mastery of new equipment, operation and repair technology, effective and safe methods of organizing production and labor;

advanced training of personnel, dissemination of advanced labor methods and economic knowledge, development of rationalization and invention;

operational dispatch control of electrical facilities, including its own sources of electrical energy, agreed with the energy supply organization;

control over the technical condition of one’s own electrical installations and the operation of one’s own sources of electrical energy operating autonomously (not being block stations);

control over the organization’s compliance with the operating modes and energy consumption limits assigned to it by the energy supply organization.

1.4.4

Non-electrical personnel performing work that may pose a risk of electric shock are assigned electrical safety group I. The list of positions and professions requiring assignment to personnel of electrical safety group I is determined by the head of the Consumer. Personnel who have mastered the electrical safety requirements related to their production activities are assigned group I with registration in a journal of the established form; no certificate is issued.

Assignment to group I is made through instruction, which, as a rule, should be completed with a knowledge test in the form of an oral survey and (if necessary) a test of acquired skills in safe working methods or providing first aid in case of electric shock. The assignment of electrical safety group I is carried out by an employee from among the electrical technical personnel of a given Consumer with an electrical safety group of at least III.

Assignment of electrical safety group I is carried out at least once a year.

Initial admission, preparation

The specified measures can be carried out only after its authorization by operational employees in charge of the electrical installation or a person appointed by the management of the facility.

Restrictions:

• it is prohibited to give out before the arrival of the performers;
• Admission is possible according to 1 order, order.

The provisions of the training order cannot be changed. If the manufacturer allows one person, then one of the performers with III gr. is involved in the event.

The admitter verifies the preparation by inspecting the object, checking with logs, operational data, messages, and then grants admission. Next, the manager and the supervisor find out from him what has been done, then they do a joint inspection by inspection. If there are no operational employees (but with their permission), the check can be performed by two specified persons.

Admission is made directly on site after checking the preparation. When the latter is not required and the work is carried out by order, the specified event is not mandatory, and it is not done on overhead lines, overhead lines, cable lines. Registration consists of marks and signatures on the orders. A record is made in 2 copies. of this document: for the observer and the admitter, and if this is one person (combining responsibilities), then in 1 copy. A mark is placed in the accounting books and operational data.

Preliminary actions of the person admitting:

• checks the identity of (groups of) performers;
• proves that there is no voltage: shows grounding or checks in another way. In power plants up to 35 kV, it is verified by touching, if possible, current-carrying elements.

1.7.10

Materials from the investigation of accidents associated with the operation of electrical installations, as well as violations of labor safety requirements, must be carefully analyzed to identify the cause and culprit of their occurrence, and to take measures to prevent such cases.

Accidents must be reported, investigated and recorded in accordance with the established procedure.

Responsibility for the correct and timely investigation and recording of accidents, execution of Form N-1 acts, development and implementation of measures to eliminate the causes of the accident lies with the head of the Consumer.

Case studies and frequently asked questions

Often, beginners ask the question whether a line or electrical installation will be considered operational if the device capable of supplying electricity is turned off.

The correct answer is yes, since an electrical installation is considered operational if electricity can be supplied using switching devices. Whether these devices are disabled is not important, because they can be turned on at any time.

In order to make it inoperative in this case, it is necessary to turn off not only the switching devices, but also to disconnect the cable through which the current flows, and also issue an appropriate order (to recognize a certain installation as inoperative).

The second equally frequent question is how to determine an existing electrical installation in practice?

In simple terms, each room where electricity passes is an electrical installation, which includes the following components: a) cable line; b) electrical panel; c) electricity consumers. In other words, almost any residential premises is a functioning electrical installation.

Moreover, several installations can be located in one room, since its boundaries are determined by the balance sheet affiliation of the areas. Even your home may have different electrical installations belonging to several companies.

This is not surprising, because one power line is also divided into areas owned by different organizations.

Classification of objects to be protected

According to GOST standards, buildings and structures that must be protected from lightning strikes are divided according to the degree of danger into ordinary and special objects. Common objects are considered to be residential and administrative buildings for commercial, industrial and agricultural purposes, the height of which does not exceed 60 meters. Special facilities include instructions for lightning protection of buildings and industrial structures:

• potentially dangerous to surrounding people and buildings;
• hazardous to the environment;
• capable, in the event of a lightning strike, of causing radiation, biological or chemical contamination - emissions exceeding sanitary standards (as a rule, this applies to state-owned enterprises);
• structures with a height exceeding 60 meters, temporary shelters, playgrounds, objects under construction and others.

For such objects, a lightning protection level of at least 0.9 is established. The owner of the structure or the customer of the construction can independently set an increased reliability class for the building.

Conventional construction projects, according to GOST, have four levels of reliability of protection against direct lightning strikes:

• first (at a peak lightning current of 200 kiloamperes), reliability – 0.98;
• second (lightning current 150 kiloamperes), reliability – 0.95;
• third (current 100 kiloamperes), reliability – 0.9;
• fourth (current 100 kiloamperes), reliability – 0.8.