DC machines

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

DC machines

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 - are produced within the time limits established by the PPR system.

Name of the test	Type of test	Test norms	Directions
24.1. Winding condition assessment	К	DC machines are switched on without drying under the following conditions: - machines with voltage up to 500 V, if the value of the insulation resistance of the windings is not less than that given in Table. 32 (Annex 3.1) - machines with voltages above 500 V, if the value of the insulation resistance of the windings is not less than that given in Table. 32 (Appendix 3.1) and the value of the absorption coefficient is not less than 1,2
24.2. Insulation resistance measurement:	K, T
1) windings		The measured value of the resistance of the windings must not be lower than those given in Table. 32 (Appendix 3.1). In operation, the insulation resistance of the windings is measured together with the circuits and cables connected to them.	The insulation resistance of the windings is measured relative to the case at a rated voltage of the winding up to 500 V with a megohmmeter for a voltage of 500 V, with a rated voltage of the winding above 500 V - with a megohmmeter for a voltage of 1000 V
2) bandages		Not less than 0,5 MΩ	The insulation resistance of bandages is measured relative to the case and the windings held by it, together with the circuits and cables connected to them.
24.3. Insulation test with increased power frequency voltage	К	See table. 33 (Appendix 3.1). Test duration - 1 min.	Not available for machines up to 200 kW for voltage up to 440 V
24.4. DC resistance measurement	К	See table. 34 (Annex 3.1)	Measurements are taken with the machine almost cold.
24.5. Removal of characteristics of idling and test of turn isolation	К	The deviation of the taken characteristic from the factory one is not standardized. When testing the coil insulation of machines with more than four poles, the average voltage between adjacent collector plates should not exceed 24 V. The duration of the test of coil insulation is 3 - 5 minutes.	The idling characteristic is taken from DC generators. The voltage rise is made up to a value equal to 130% of the nominal
24.6. Measurement of air gaps under the poles	К	Gaps at diametrically opposite points should not differ from one another by more than ±10% of the average gap	The measurement is made for generators, as well as for electric motors with a power of more than 3 kW
24.7. Checking the operation of the machine at idle	К	The no-load current is not standardized, the working condition of the machine is assessed	Takes at least 1 hour.
24.8. Determining speed control limits	К	Limits of regulation must correspond to the technological data of the mechanism	Produced at idle and under load for electric motors with variable speed

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:

A New Way to Control and Manipulate Optical Signals 05.05.2024

The modern world of science and technology is developing rapidly, and every day new methods and technologies appear that open up new prospects for us in various fields. One such innovation is the development by German scientists of a new way to control optical signals, which could lead to significant progress in the field of photonics. Recent research has allowed German scientists to create a tunable waveplate inside a fused silica waveguide. This method, based on the use of a liquid crystal layer, allows one to effectively change the polarization of light passing through a waveguide. This technological breakthrough opens up new prospects for the development of compact and efficient photonic devices capable of processing large volumes of data. The electro-optical control of polarization provided by the new method could provide the basis for a new class of integrated photonic devices. This opens up great opportunities for ... >>

Primium Seneca keyboard 05.05.2024

Keyboards are an integral part of our daily computer work. However, one of the main problems that users face is noise, especially in the case of premium models. But with the new Seneca keyboard from Norbauer & Co, that may change. Seneca is not just a keyboard, it is the result of five years of development work to create the ideal device. Every aspect of this keyboard, from acoustic properties to mechanical characteristics, has been carefully considered and balanced. One of the key features of Seneca is its silent stabilizers, which solve the noise problem common to many keyboards. In addition, the keyboard supports various key widths, making it convenient for any user. Although Seneca is not yet available for purchase, it is scheduled for release in late summer. Norbauer & Co's Seneca represents new standards in keyboard design. Her ... >>

The world's tallest astronomical observatory opened 04.05.2024

Exploring space and its mysteries is a task that attracts the attention of astronomers from all over the world. In the fresh air of the high mountains, far from city light pollution, the stars and planets reveal their secrets with greater clarity. A new page is opening in the history of astronomy with the opening of the world's highest astronomical observatory - the Atacama Observatory of the University of Tokyo. The Atacama Observatory, located at an altitude of 5640 meters above sea level, opens up new opportunities for astronomers in the study of space. This site has become the highest location for a ground-based telescope, providing researchers with a unique tool for studying infrared waves in the Universe. Although the high altitude location provides clearer skies and less interference from the atmosphere, building an observatory on a high mountain poses enormous difficulties and challenges. However, despite the difficulties, the new observatory opens up broad research prospects for astronomers. ... >>

Random news from the Archive

Huge unknown lake found under Antarctica 01.05.2016

Antarctic ice hides under itself an unknown lake 100 km long.

Such subglacial lakes are of great interest to science, as they may harbor unique forms of life, locked in isolation from the rest of the world for millions of years. Although not larger than Lake Vostok (Vostok is 240 km long and 60 km wide), the new lake is much closer to the research stations and will be easier to approach and study in detail, says Martin Sigert, a member of the team that discovered new geographical feature.

The guess about the existence of the lake is based on satellite images, where scientists have identified grooves on the surface of the ice that exactly match those observed above the already known subglacial lakes and channels. "We saw these strange lines on the surface and from them we suggested that there are massive channels 1000 km long, as well as a relatively large subglacial lake," Siegert said.

He says that the new lake is about 100 km long and only 10 km wide, shaped more like a ribbon, and the long channels and canyons that emerge from it stretch for 1000 km along the east coast of Antarctica.

The guess about the existence of the lake is based on satellite images, where scientists have identified grooves on the surface of the ice that exactly match those observed above the already known subglacial lakes and channels. "We saw these strange lines on the surface and from them we suggested that there are massive channels 1000 km long, as well as a relatively large subglacial lake," Siegert said.

He says that the new lake is about 100 km long and only 10 km wide, shaped more like a ribbon, and the long channels and canyons that emerge from it stretch for 1000 km along the east coast of Antarctica.

Other interesting news:

▪ Rugged smartphone Blackview BV8900 with a thermal imager

▪ Updated EU requirements for power consumption of appliances in sleep mode

▪ Perfect mannequins scare away buyers

▪ 2004 through the eyes of Intel

▪ Jennie to demonstrate wireless near video over IEEE802.15.4

News feed of science and technology, new electronics

Interesting materials of the Free Technical Library:

▪ section of the site Normative documentation on labor protection. Article selection

▪ article by Han Fei. Famous aphorisms

▪ What were the development paths of France after de Gaulle? Detailed answer

▪ article Occupational diseases and their classification

▪ article Expanding the possibilities of a light-dynamic installation. Encyclopedia of radio electronics and electrical engineering

▪ article Pinout for Nokia 3210. Encyclopedia of radio electronics and electrical engineering

Leave your comment on this article:

All languages of this page

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