AC motors

Free technical library

ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
Free library / Encyclopedia of radio electronics and electrical engineering / Electrician

Annex 3. Standards for testing electrical equipment and apparatus for electrical installations of consumers

AC motors

Free technical library

Encyclopedia of radio electronics and electrical engineering / Rules for the technical operation of consumer electrical installations (PTE)

Comments on the article

K, T, M - are produced within the time limits established by the PPR system.

Name of the test	Type of test	Test norms	Directions
23.1. Insulation resistance measurement		For electric motors with a power of more than 5 MW, measurements are made in accordance with established standards and manufacturer's instructions	Insulation resistance is measured with a megohmmeter for voltage: 500 V - for electric motors up to 500 V 1000 V - for electric motors up to 1000 V 2500 V - for electric motors with voltages above 1000 V
1) stator windings, for electric motors with voltages above 1000 V or power from 1 MW to 5 MW	K, T	Insulation resistance must not be lower than the values given in Table. 28(Annex 3.1)
2) stator windings, for electric motors for voltage up to 1000 V	K, T	The insulation resistance of the windings must be at least 1 MΩ at a temperature of 10 - 30 ° C, and at a temperature of 60 ° C - 0,5 MΩ;	The resistance values apply to all types of insulation
3) absorption coefficient (ratio R₆₀/ R₁₅) stator windings of electric motors with voltage above 1000 V	K, T	R value₆₀ / _R15 must be at least 1,3 for electric motors with thermosetting insulation and at least 1,2 for electric motors with compound mica insulation	Produced with a megohmmeter for a voltage of 2500 V for electric motors with a power of 1 to 5 MW, as well as a smaller power for outdoor electric motors with compounded mica insulation
4) rotor windings	K, T	Insulation resistance must be at least 0,2 MΩ	It is produced for synchronous electric motors and asynchronous electric motors with a phase rotor with a voltage of 3 kV and higher or a power of more than 1 MW with a megohmmeter for a voltage of 1000 V (500 V is allowed)
5) temperature indicators with connecting wires	К	No limitation	Produced by a megohmmeter for a voltage of 250 V
6) bearings	К	No limitation	Produced for electric motors with a voltage of 3 kV and above, the bearings of which are insulated relative to the housing, are produced relative to the base plate with fully assembled oil pipelines with a megohmmeter for a voltage of 1000 V during repairs with a recessed rotor
23.2. Assessment of the state of insulation of electric motor windings before switching on	К	Electric motors are switched on without drying, if the values of the insulation resistance of the windings and the absorption coefficient are not lower than the values given in clause 23.1
23.3. Power frequency surge test	К	The value of the test voltage is taken from Table. 29 (Annex 3.1)	By decision of the technical manager of the Consumer, testing of electric motors with voltage up to 1000 V may not be carried out
23.4. DC resistance measurement:	К
1) stator and rotor windings;		The measured values of the resistances of various phases of the windings, reduced to the same temperature, should not differ from each other and from the initial data by more than ± 2%	Produced for electric motors with a voltage of 3 kV and above, the resistance of the rotor winding is measured for synchronous motors and electric motors with a phase rotor
2) rheostats and ballast resistors		The resistance should not differ from the original values by more than 10%	For electric motors with a voltage of 3 kV and above, it is produced on all branches. For the rest, the total resistance of the rheostats and starting resistors is measured and the integrity of the taps is checked
23.5. Measuring gaps between rotor and stator steel	К	For electric motors with a power of 000 kW and more, for all electric motors of critical mechanisms, as well as for electric motors with remote plain bearings, the dimensions of the air gaps at points located along the circumference of the rotor and shifted relative to each other by an angle of 90 °, or at points specially provided during manufacture electric motor, should not differ by more than 10% from the average size	It is produced if the design of the electric motor allows
23.6. Measurement of clearances in plain bearings	К	The increase in clearances in plain bearings in excess of the values \u30b\u3.1bgiven in table. XNUMX (Appendix XNUMX), indicates the need to refill the liner	-
23.7. Checking the electric motor at idle or with an unloaded mechanism	К	The no-load current must not differ by more than 10% from the value specified in the catalog or in the manufacturer's instructions. The duration of the test is 1 hour.	Produced for electric motors with a voltage of 3 kV and above and a power of 100 kW or more
23.8. Vibration measurement of motor bearings	K, M	The vertical and transverse component of the vibration, measured on the bearings of the electric motors articulated with the mechanisms, must not exceed the values specified in the factory instructions. In the absence of such instructions, see table. 31(Annex 3.1)	Produced for electric motors with a voltage of 3 kV and above and electric motors of critical mechanisms
23.9. Measuring the run-up of the rotor in the axial direction	К	Not higher than 4 mm, unless a different rate is specified in the factory instructions	Produced for electric motors with plain bearings, critical mechanisms or in case of excavation of the rotor
23.10. Checking the operation of the electric motor under load	К	Produced with an electric motor load of at least 50% of the rated	Produced for electric motors with voltages above 1000 V
23.11. Hydraulic testing of the air cooler	К	Produced by excess pressure of 0,2 - 0,25 MPa (2 - 2,5 kgf / cm²), unless otherwise specified by the manufacturer	Test duration - 5 - 10 min.
23.12. Checking the health of the squirrel-cage rotor bars	К	The rods of squirrel-cage motors must be intact	Produced for asynchronous electric motors with a power of 100 kW or more
23.13. Exciter testing		Produced for synchronous motors in accordance with the requirements of factory instructions

See other articles Section Rules for the technical operation of consumer electrical installations (PTE).

Read and write useful comments on this article.

<< Back

Latest news of science and technology, new electronics:

Machine for thinning flowers in gardens 02.05.2024

In modern agriculture, technological progress is developing aimed at increasing the efficiency of plant care processes. The innovative Florix flower thinning machine was presented in Italy, designed to optimize the harvesting stage. This tool is equipped with mobile arms, allowing it to be easily adapted to the needs of the garden. The operator can adjust the speed of the thin wires by controlling them from the tractor cab using a joystick. This approach significantly increases the efficiency of the flower thinning process, providing the possibility of individual adjustment to the specific conditions of the garden, as well as the variety and type of fruit grown in it. After testing the Florix machine for two years on various types of fruit, the results were very encouraging. Farmers such as Filiberto Montanari, who has used a Florix machine for several years, have reported a significant reduction in the time and labor required to thin flowers. ... >>

Advanced Infrared Microscope 02.05.2024

Microscopes play an important role in scientific research, allowing scientists to delve into structures and processes invisible to the eye. However, various microscopy methods have their limitations, and among them was the limitation of resolution when using the infrared range. But the latest achievements of Japanese researchers from the University of Tokyo open up new prospects for studying the microworld. Scientists from the University of Tokyo have unveiled a new microscope that will revolutionize the capabilities of infrared microscopy. This advanced instrument allows you to see the internal structures of living bacteria with amazing clarity on the nanometer scale. Typically, mid-infrared microscopes are limited by low resolution, but the latest development from Japanese researchers overcomes these limitations. According to scientists, the developed microscope allows creating images with a resolution of up to 120 nanometers, which is 30 times higher than the resolution of traditional microscopes. ... >>

Air trap for insects 01.05.2024

Agriculture is one of the key sectors of the economy, and pest control is an integral part of this process. A team of scientists from the Indian Council of Agricultural Research-Central Potato Research Institute (ICAR-CPRI), Shimla, has come up with an innovative solution to this problem - a wind-powered insect air trap. This device addresses the shortcomings of traditional pest control methods by providing real-time insect population data. The trap is powered entirely by wind energy, making it an environmentally friendly solution that requires no power. Its unique design allows monitoring of both harmful and beneficial insects, providing a complete overview of the population in any agricultural area. “By assessing target pests at the right time, we can take necessary measures to control both pests and diseases,” says Kapil ... >>

Random news from the Archive

Chip MediaTek Helio P22 22.05.2018

MediaTek has expanded its family of mobile processors with the Helio P22 model, designed for relatively inexpensive smartphones and phablets.

The chip will be manufactured by TSMC using 12nm FinFET technology. The product is based on eight ARM Cortex-A53 cores clocked at up to 2,0 GHz.

The processor includes an IMG PowerVR GE8320 graphics accelerator with a frequency of 650 MHz. Declared support for displays with an aspect ratio of 20:9 and a resolution of 1600 x 720 pixels.

The Helio P22 platform allows you to use up to 6 GB of LPDDR4X-1600 RAM. Mobile devices based on the chip will be able to carry an eMMC 5.1 flash module on board.

Declared support for dual cameras with sensors 13 megapixels + 8 megapixels, as well as single cameras with a resolution of up to 21 megapixels. The function of recognizing users by face can be implemented.

The processor also provides support for wireless communication Wi-Fi 902.11a/b/g/n/ac and Bluetooth 5.0, satellite navigation Beidou, Galileo, GLONASS and GPS, FM radio. The chip allows you to use two SIM-cards in 4G/VoLTE mode.

The first Android devices based on the Helio P22 platform are expected to debut at the end of the current quarter.

Other interesting news:

▪ You can predict something by the hand

▪ Exhibition of domestic robots

▪ Erasing memories

▪ Thermoid converts heat into electricity

▪ 100 Mbps for ISS

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ site section Regulators of current, voltage, power. Article selection

▪ article Moscow does not believe in tears. Popular expression

▪ article Who opposed the Russian troops led by Dmitry Donskoy in the Battle of Kulikovo? Detailed answer

▪ article Examination of insured events in connection with an occupational disease

▪ article Antenna for the field day. Encyclopedia of radio electronics and electrical engineering

▪ article Lost card. Focus Secret

Leave your comment on this article:

All languages of this page

Home page | Library | Articles | Website map | Site Reviews