Norms of acceptance testing of electrical equipment. Acceptance tests of the electrical installation. Documentation and visual inspection

Tests and measurements in electrical installations are carried out before their acceptance into operation within the time limits determined by the frequency of preventive tests, as well as during major and current repairs of electrical equipment.

Carrying out reception acceptance tests in electrical installations, GOST R 50571.16-99 "Electrical Installations of Buildings, Part 6. Tests, Chapter 61. Acceptance Tests" is regulated, as well as the Rules for Electrical Installations, Chapter 1.8. "Norms of acceptance tests".

Checking the correct phase sequence

Include Functional Requirements Document project teams as part of any contract or purchase order with a system vendor or integrator. He should try to include testing as much functionality as possible in the factory, as well as testing all interfaces between equipment and systems. The supplier must compile a set of documents that can support testing and serve as a reference for test results, including. Contract specifications and copies of all references mentioned in the specification.

Acceptance tests and measurements in electrical installations represent a whole range of works. These works include:

testing and measurements in electrical installations;
drawing up a technical report and other necessary documentation;
obtaining and approval in Rostekhnadzor of the permit of the electrical installation for operation.

The main stages of measuring work in electrical installations

1. Visual inspection of the state of the electrical facilities of the facility.

All drawings for the project, including drawings from other vendors that describe interfaces. Checking equipment is an important step that can be done at any convenient location. Review the BOM line by line, checking equipment or drawings against the BOM, including any change orders. Job review. Consider issues that may arise during installation or use of the equipment, such as lifting points and safe access to components for maintenance, etc. equipment testing according to the supplier's approved procedure, this should include functional testing and adjustment Special testing may be required to determine any major nonconformities identified during testing.

When expanding or reconstructing an existing electrical installation, it is necessary to make sure that its expansion or reconstruction meets the requirements of the GOST R 50571 set of standards and does not reduce the safety of the existing part of the electrical installation. Visual inspection should precede the test and be carried out both with the electrical installation completely disconnected and in operating mode.

Pay attention to the software and firmware versions in the equipment under test. Review the draft guidelines and note any shortcomings. Confirm that the supplier has and will provide hardware, software and tracking records. Confirm the supplier's schedule to complete all documentation.

All nonconformities and system nonconformities must be compiled into a list of nonconformities, including a "time to completion" column, such as before shipping. The list of discrepancies helps to prioritize and focus work towards system completion with minimal impact on the project's critical path. The salesperson needs to be monitored periodically to ensure continued attention. Project management should consider this on a case by case basis.

2. Measurement of current spreading resistance of grounding devices and ground electrodes.

Grounding devices must comply with the requirements state standards, rules for the installation of electrical installations, building codes and regulations and other regulatory and technical documents, ensure the safety of people, operating modes and protection of electrical installations (PTE EP Ch.2.7.p.2.7.2).

Testing of electrical installations

If a newly installed power grid and its associated components are to be operated safely and reliably, several key components will be required. The power system and components must be designed and engineered correctly. Installation must comply with all applicable codes and standards and be carried out by qualified contractors and suppliers. Verification of all of the above must be conducted through an independent, independent verification process.

It is necessary to provide quality equipment.
All information should be documented and archived for future use.

Although these are not complex requirements, all too often these basic elements are not met when installing and commissioning a power system.

3. Checking the presence of a circuit between the grounding and grounding elements.

This test is carried out in accordance with GOST 12.1.030-81 in order to ensure electrical safety by checking the correct connection and integrity of all protective conductors, grounding conductors, protective earthing, potential equalization.

Poorly written specifications and contracts, misunderstandings, budgetary constraints, unqualified contractors, inability to use accredited testing and commissioning companies, or a host of other reasons can lead to problems installing and operating an electrical system.

Electrical testing can be a complex process requiring skilled workers and advanced test equipment. This article illustrates the relationship between existing national consensus standards, technical certifications, field acceptance tests and determining the health of newly installed electrical equipment - when answering the question: How can the owner of the equipment provide an objective and qualified assessment of the installed system?

According to the results of measurements by the electrotechnical laboratory, the following is determined:

safety of operation of the electrical equipment installed and connected to the power grid;
continuity of protective conductors grounding stationary (if necessary, portable or mobile) electrical equipment or devices;
absence of dangerous potentials on grounded electrical equipment elements.

4. Measurement of insulation resistance of wires and cables.

Electrical industry. At present, the electrical testing industry is wide and varied both in terms of the level of services provided and the qualifications of those who provide the services. Usually the owner of the facility that is being built, such as a factory, bank, school, etc. Specifies in contract documents, usually in section 300, that the owner, architect, or engineer must use the services of an independent, third-party electrical testing firm. Third party test companies perform the required electrical tests and provide test data reports for the installed electrical system that indicate the operation or inoperability of the equipment as determined by field testing.

The insulation resistance of electrically conductive lines with voltage up to 1000V must be at least 0.5 (1.0) MΩ. (PTE EP Table 6, clause 6.2, Appendix No. 3 PTE EP). According to the results of measurements by the electrotechnical laboratory, the following is determined:

suitability of electrically conductive lines for safe operation;
suitability of inductive consumers for technological suitability and for safe operation.

5. Checking the coordination of the parameters of the "phase - zero" circuit with the characteristics of protection devices and the continuity of protective conductors.

They also differ from manufacturer's factory tests. Field testing conducted by a third party testing company confirms that the equipment, after it left the factory and after installation, was not damaged and correctly installed and functioning as intended by the factory and the design engineer. This data assists electrical inspection authorities in deciding whether the equipment is suitable for service.

The cost of testing

Fortunately, there are a series of standards and certifications for the field acceptance of power distribution equipment. Owners can use these standards to ensure their own High Quality installation and acceptance testing of their electrical assets and that the technicians and engineers performing the tasks associated with these acceptance tests are entitled to do so.

The object of measurement is the circuit "phase-zero", "phase-ground" and "phase-phase" in electrical installations with voltage up to 1000V with a solidly grounded neutral, their impedance. The measured value is the impedance of the phase-zero circuit. Verification of protection measures against indirect contact is carried out during acceptance and operational tests in accordance with the requirements of the PUE, p.p. 1.7.78, 1.7.79.

Entering technicians and business owners into the field for testing is often an extension of their current job, such as electrical contractors, apprentice electricians, utility workers, ex-military, or even someone who works for a testing company and maintenance that performs this type of work, there are also technical programs at colleges that offer special educational tracks in electrical skills such as the " Electrical systems offered at Texas State Technical College in Waco, Texas.

6. Checking and testing of circuit breakers controlled by differential current.

The object of measurements are residual current devices (RCDs) and circuit breakers, including differential protection in electrical installations with voltage up to 1000 V. According to the measurement results, depending on the task, the electrical laboratory determines:

For some people, they get into the business because there is money to be made and business testing is largely unregulated. How does this affect the electrical inspector? For example, a few years ago in the northeast, an experienced company came to the site to test protective relays connected to the facility's power system. This particular contractor has been doing this job for several years and the staff has never had a problem with his work. There were no unplanned relay-related outages, the relays looked good, and test reports indicated that all repeaters were within manufacturer's specifications.

touch voltage;
differential protection operation time;
operating current of differential protection.

7. Checking the correct phase sequence.

Most three-phase consumers require a certain phase rotation in a three-phase power supply system and can be damaged if it is disturbed. Based on the results of measurements, the electrical laboratory determines the order of phase sequence in the connections of input, distribution and group electrical panels and current collectors.

Underground feeder cable failure but relay maximum current, protecting this scheme, did not work. The entire facility went dark as the power grid cascaded from one level of the system to the next, which should have been prevented by proper functioning of the safety relays and a valid coordination study. When the site technicians investigated, it was found that the original packaging had never been removed from the relay, and this packaging was preventing the induction disc from turning.

The contractor apparently came every year, set up his test equipment, pulled out the relays, put them away, faked the testing process, returned the relays, and continued on his way. The site personnel did not have the experience to determine if the contractor was doing a good job or a bad job, or even what they were supposed to be doing. The contractor filed for bankruptcy, went out of business, and a few weeks later he was back in business under a new name. He had no business-related assets, was protected from a personal lawsuit, and basically walked away from all the mess.

8. Measurements of supply voltage, current consumption and frequency.

When data is needed electrical network the electrical laboratory produces these measurements in input devices, power and distribution electrical panels.

9. Measurement of illumination.

If it is necessary to obtain data on illumination, the electrical laboratory makes appropriate measurements, both indoors and outdoors.

Electrical Testing: A challenging task with unique challenges. The electrical industry has installation standards such as national standards electrical installations developed by the National Association of Electrical Contractors. This certification and licensing is done by other agencies, usually state or municipal governments, to ensure that code practitioners maintain the required criteria.

Low voltage fusible connection with damaged contacts due to high resistance. A common field test is to test the contact resistance with a low resistance digital ohmmeter. By performing these tests accurately, interpreting the results, and completing the test report so that the information is clearly and accurately communicated to the equipment owner, all areas requiring many years of training and experience to operate well and safely.

10. Checking automatic switches with voltage up to 1000V.

The object of measurements are circuit breakers that serve to protect distribution networks alternating current and power receivers in emergency cases in case of damage to the insulation, the occurrence of overload currents and short circuits. According to the results of measurements by the electrotechnical laboratory, the following is determined:

If grounded equipment is not working properly, the results can be very dangerous. With the complexity of power systems, the ever-changing technology associated with equipment, and the speed at which projects progress, how do you reassure yourself of what a technician should do to test third parties? For example, when a technician shows up on site to test a grounding system, how do you know they can do the job right?

If he doesn't, life could be at stake if that grounding system doesn't work properly. There are currently no federal requirements for certification of electrical technicians or their companies. Anyone can buy a few pieces of test equipment, buy a couple of uniforms and a truck, and start an electrical testing company. This is how several companies were created. Many of these people have experience and expertise in a specific field of protective device maintenance through certain types of installed equipment or testing methods, but are in a "learn like you" program for the rest of the power system.

the time of operation of the releases of the installations of protection against short-circuit currents;
time of operation of releases of overcurrent protection installations.

Based on the results of the measurements, a technical report is drawn up, consisting of a set of relevant protocols. In each protocol, a conclusion is given on the compliance of the measurement results with the current norms and rules, there are notes and conclusions. All comments on the visual inspection and the measurements taken are recorded in the defective statement of the technical report. The defect list contains recommendations for eliminating defects, comments and deviations from regulatory requirements.

When measuring and testing, the electrical laboratory uses measuring equipment of domestic and foreign production, included in State Register measuring instruments of Russia and passed the state check. Measurements, data analysis and compilation technical documentation in the prescribed form is produced by qualified engineering and technical personnel of the laboratory. The personnel involved in the work has individual certificates of advanced training in the field of testing and measurements in electrical installations up to 1000V and certificates for checking knowledge of current norms and rules in the field of electrical safety. Operational-repair and administrative-technical personnel undergo a knowledge test in the services of ROSTEKHNADZOR, each specialist has an electrical safety clearance group of at least IV.

The cost of testing

The cost of testing depends on the functional purpose of the premises, its area, the number of test points, etc. etc. I would like to draw your attention to the fact that our company does not provide a package of documents without testing, since during the identified defects it is possible to avoid fires in electrical wiring.

The average cost of work on measurements is on average from 18,000 rubles. We will be able to determine the exact cost of the work after receiving terms of reference, indicating the number of tested points.

To order testing from us, you just need to call one of our phones or fill out an On-line application.

Advantages of cooperation with Alfa Service Group

Alfa Service Group LLC has its own registered electrical laboratory (registration No. 4206 dated September 30, 2011). Testing equipment undergoes annual state verification.

Our experts have extensive experience, apply modern equipment, work professionally and promptly, so you can be sure of the quality and reliability of the work of Alfa Service Group.

It is most profitable to order the services of an electrical laboratory in a complex of other services to ensure fire safety object, since in this case a flexible system of discounts works, and our offer will be economically attractive for you.

Conducting periodic and acceptance tests of electrical installations is carried out in accordance with GOST R and other regulatory documents. Below we provide a list of them, which must be guided by the planning and implementation of acceptance and other tests.

Regulations

The main documents currently in force are (according to the GOST-99 list):

GOST R 50571.1-93 (IEC 364-1-72, IEC 364-2-70) Electrical installations of buildings. Key points
GOST R 50571.2-94 (IEC 364-3-93) Electrical installations of buildings. Part 3. Key Features
GOST R 50571.3-94 (IEC 364-4-41-92) Electrical installations of buildings. Part 4. Security requirements. Protection against electric shock
GOST R 50571.4-94 (IEC 364-4-42-80) Electrical installations of buildings. Part 4. Security requirements. Thermal protection
GOST R 50571.5-94 (IEC 364-4-43-77) Electrical installations of buildings. Part 4. Security requirements. Protected against overcurrent
GOST R 50571.7-94 (IEC 364-4-46-81) Electrical installations of buildings. Part 4. Security requirements. Separation, shutdown, control
GOST R 50571.10-96 (IEC 364-5-54-80) Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Chapter 54
GOST R 50571.15-97 (IEC 364-5-52-93) Electrical installations of buildings. Part 5. Selection and installation of electrical equipment. Chapter 52

The main requirements for conducting periodic and acceptance tests of electrical installations are set out in GOST R 50571. According to them, “each electrical installation up to 1000V during installation and / or after it, before commissioning, must be inspected and tested to make sure how it it is possible that the requirements of the complex standard are met. For electrical installations up to and above 1000V (up to 500kV), inclusive, after installation, electrical measuring and commissioning work must be performed in the scope of the requirements of the Electrical Installation Code, Chapter 1.8 "Acceptance Test Standards".

Documentation and visual inspection

Carrying out periodic and acceptance tests of electrical installations begins with the presentation to specialist experts project documentation, which includes a full range of certificates, installation documents, instructions, and so on. In accordance with them, a test plan should be drawn up. Before starting work, it is required to remove outside personnel from the testing area and equip the place of work with protective equipment and warning posters in accordance with the requirements of the regulatory document "Labor Safety Rules". It is also necessary to ensure that other equipment and electrical installations cannot be damaged. Testing of electrical installations should be carried out by certified specialists, and not by representatives of personnel allocated for this purpose who do not have appropriate training, or who have such training, but do not have permission. Usually, it is recommended to involve third-party specialists from electrical laboratories registered with Rostekhnadzor to test electrical installations. This is necessary both for compliance with labor protection rules and for compiling test reports that must comply with the requirements of supervisory organizations.

Tests of electrical installations, both acceptance and periodic, should begin with a visual inspection. Equipment must comply with safety requirements and relevant standards for testing and electrical installations. This can be determined by comparing the marking on the equipment itself with the requirements of GOST, equipment certificates and attached documents. Then it is necessary to check the condition of insulation and protection casings, protective shells of barriers, fences and barriers, warning labels. Special attention when inspecting electrical installations before testing, one should pay attention to the condition of current-carrying parts.

“the presence of fire seals and other means that prevent the spread of fire, as well as protection from thermal effects;
selection of conductors for continuous current and voltage loss;
selection of protection and signaling devices and settings for their operation;
selection of equipment and protective measures corresponding to external influences;
marking of zero working and protective conductors of electrical installations;
the presence of diagrams, warning labels or other similar information;
marking of circuits, fuses, terminals, etc.;
correct connection of conductors;
availability for convenient operation, identification and maintenance of the electrical installation in operation.

Testing of electrical installations

GOST R 50571 establishes that “depending on the composition of the protective measures used, the following checks, measurements and tests of electrical installations up to 1000V after installation should be performed, preferably in the following sequence:

visual inspection;
checking the characteristics of circuit breakers, dif. Automata, RCD;
measurement of insulation resistance of wires, cables;
checking the continuity of protective conductors, including conductors of the main and additional potential equalization systems;
measurement of resistance of grounding devices;
phase-zero loop test
ATS performance check;

When conducting certification tests of an accredited EL (additionally), the following are carried out:

measurement of insulation resistance (conductivity) of floors and walls;
checking the static load of fixture hooks (chandeliers);
checking sockets for pull-out (mechanically);

For electrical installations above 1000V, the parameters and characteristics of each element of equipment and relay protection (RP) of cells (KRU) are checked at operating settings.
The Technical Report or measurement protocols must contain the conclusions and results of all checks for compliance with the requirements of the Regulatory Documents and the OM of the plants - manufacturers of equipment and relay protection units.
Since all tests and measurements are carried out sequentially and their results are reflected in the protocols, each non-corresponding measurement point means the presence of some kind of malfunction. The malfunction is determined, fixed and eliminated, after which the test is carried out again until there are no comments. Tests of electrical installations, both acceptance and periodic, can be carried out with various instruments, measuring instruments that have been verified and according to methods developed by the head of the EL and approved technical director or head of the organization.

Insulation tests for electrical installations

One of the checks is to measure the continuity of the protective conductors. “It is recommended that this test be performed using a power source having an open-circuit voltage of 4 to 24 V dc or ac at a test current of at least 0.2 A.” The insulation resistance of an electrical installation is carried out in conjunction with other measurements: “Insulation resistance must be measured:

between current-carrying conductors, taken in turn "two to two" relative to each other.
between each current carrying conductor and ground.

The insulation resistance measured at the test voltage is considered satisfactory if each circuit with disconnected electrical receivers has an insulation resistance not less than the corresponding permissible value. Measurements must be taken on DC. If the circuit has electronic devices, then the insulation resistance between the phase and neutral working conductors connected together and the "ground" must be measured. These provisions of GOST when testing electrical installations are associated with tables attached to the standards, which indicate the values of both insulation resistance and test voltage.

Another test of electrical installations is protection by separation of circuits. The current-carrying parts of the circuit must be isolated from each other, and the insulation resistance must first be measured, and then the electrical installation, together with the connected electrical equipment, must be tested. Testing electrical installations is not limited to measuring the insulation of the mechanisms themselves: the resistance of the floor and walls is also measured, since the output of electricity can also be carried out through them, especially if there are through holes in the floor and walls. metal constructions, a hygroscopic material is used, running water, or there is a permanent high humidity. The regulations state that “for insulating (non-conductive) rooms, zones, areas, at least three measurements must be taken in each room. One of the measurements should be made approximately 1 m from the third-party conductive parts located in this room. The other two measurements must be taken at a greater distance. The above series of measurements shall be made for each room surface of the electrical installation under test."

Checking RCDs

To date, there are several systems, requirements for checking devices automatic shutdown from the power source. GOST 1999 distinguishes the following systems: TN, TT and IT. Electrical installation manuals provide the following information:

“TN system - a system in which the neutral of the power source is deafly grounded, and the open conductive parts of the electrical installation are connected to the deafly grounded neutral of the source by means of zero protective conductors;
TN-C system - a TN system in which the zero protective and zero working conductors are combined in one conductor throughout its entire length;
TN-S system - a TN system in which the zero protective and zero working conductors are separated along its entire length;
TN-C-S system - a TN system in which the functions of the zero protective and zero working conductors of the electrical installation are combined in one conductor in some part of it, starting from the power source;
IT system - a system in which the neutral of the power supply is isolated from earth or earthed through devices or devices with high resistance, and the exposed conductive parts of the electrical installation are earthed;
TT system - a system in which the neutral of the power source is solidly grounded, and the open conductive parts of the electrical installation are grounded using a grounding device electrically independent of the solidly grounded neutral of the source.

So, for TN, when testing electrical installations, the resistance of the “phase-zero” loop is checked, in the event that there are no calculated measurements, or there are no measurement results of protective conductors. Otherwise, it is enough to calculate, knowing the length and transverse section specified conductors.

Conducting periodic and acceptance tests of electrical installations for TN systems continues with a performance check protective device(i.e., according to GOST, “checking the setting currents of circuit breakers and currents of fuse links, as well as testing RCDs”). The CT system is first subjected to an earthing resistance measurement test for exposed conductive parts of an electrical installation, and then to a test of the protective device characteristics. Like all tests of electrical installations, the second stage begins with a visual inspection of the condition of the RCD, and continues with a test of: setting, fuse-link current, continuity (for fuses). Installation tests for the IT system “Compliance with the requirements must be checked by calculating or measuring the first earth fault current. This measurement is not required if all exposed conductive parts of the installation are connected to the earthing system of the power supply in case the system is connected to earth through a resistance. Measurements are performed only if the calculation cannot be made due to the absence of all parameters. However, precautions must be taken when performing the measurement to avoid the danger of a double fault to ground. When measuring the resistance of the "phase-zero" loop, it is necessary to ensure that a small resistance is connected between the neutral point of the system and the protective conductor at the connection point of the electrical installation.

Grounding, strength, polarity

Usually, when conducting periodic and acceptance tests of electrical installations for measuring and testing the resistance of the ground electrode, a measurement method using two auxiliary ground electrodes is used. However, it must be remembered that such a measurement is possible only if there is a sufficiently large free space: in urban conditions it is practically impossible in a TT system, for example, to provide two auxiliary electrodes for testing an electrical installation. These measurements also include measurements of the phase-zero loop ("phase-zero", "neutral", etc.) Measurements are performed according to a special technique at a frequency equal to the nominal frequency of the network. GOST gives Full description method and ratings. Since the value of the neutral impedance can be affected by very big number factors that need to be minimized.

When conducting periodic and acceptance tests of electrical installations, the value of impedance can be affected by metal pipes in which the cable or pipes lie nearby, cables with metal sheaths, busbars. This fact must be taken into account and recalculations should be carried out according to the tables attached to the standards. In some electrical installations, it is prohibited to install single-pole switching devices in the zero working conductor. Thus, when conducting periodic and acceptance tests of electrical installations, it is necessary to check that such installations are included only in the phase conductor. With regard to dielectric strength, it is usually only tested on equipment that is manufactured or upgraded at the installation site. If the equipment has not been upgraded, altered and has not been overhaul, then the measurement and test of dielectric strength is not carried out.

Also, when conducting periodic and acceptance tests of electrical installations, it is important to check the performance of complex complete devices. These include, for example, control panels, interlocking and control systems, switchgears, drives and so on. During measurements, in the event of a malfunction, it is determined which node is failing, adjusted or changed, then tested and measured again. Electrical installation devices must be properly mounted, installed and adjusted in accordance with the requirements of the RF ND in the field of Energy. basis normative documentation electrical installations up to 1000V are used by the GOST R 50571 system.

Registration of results

Registration of the results of periodic and acceptance tests of electrical installations are indicated in the Regulatory documents: GOST R 17025-2006, GOST R 50571. We list some of them:

"one. The test report must contain reliable, objective and accurate test results, data on test conditions and measurement errors, a conclusion on the compliance of the tested electrical installation of the building with the requirements of regulatory documents and project documentation, and show accurately, clearly and unambiguously the test results and other information related to them.

2. The test report must contain the following basic information:

name and address testing laboratory;
registration number, date of issue and validity period of the accreditation certificate, name of the accrediting organization that issued the certificate (if any) or certificate of registration with the state energy supervision bodies;
the number and date of registration of the test report, the numbering of each page of the report, as well as the total number of pages; - full name of the electrical installation and its elemental composition;
OKP code;
name of the organization or surname, name, patronymic of the customer and his address;
date of receipt of the application for testing the electrical installation;
name and address of the installation organization;
information about the design documentation, in accordance with which the electrical installation was installed;
information about acts of hidden work (organization, number, date); - date of testing;
place of testing;
climatic conditions for testing (temperature, humidity, pressure);
the purpose of the tests (acceptance, for the purposes of certification, collation, control);
test program (the scope of tests in the form of a listing of paragraphs (sections) of a regulatory document for the requirements for an electrical installation and its elemental composition).

In the appendix to the test report of electrical installations, a program is provided that indicates:

« normative document, for compliance with the requirements of which tests were carried out (standard, rules, norms, etc.);
a list of the test equipment and measuring instruments used, indicating the name and type of test equipment and measuring instruments, the range and accuracy of measurements, data on the number of the metrological certificate or certificate and the date of the last and next certification and verification;
values of indicators according to regulatory documents and tolerances, if necessary;
actual values of indicators of tested electrical installations, indicating the measurement error, if necessary;
conformity conclusion normative document for each indicator;
information on an additional test report performed on a subcontract basis (if any);
conclusion on the compliance (or non-compliance) of the tested electrical installation, its elements with the requirements of standards or other regulatory documents;
signatures and positions of persons responsible for testing and execution of the test report, including the head of the testing laboratory;
seal of the testing laboratory (or organization);
an indication of the inadmissibility of partial or complete reprinting or reproduction without the permission of the customer (or testing laboratory) (on the title page). The title page indicates that the test report applies only to the electrical installation.