This article will contain information about complete switchgears. Their technical characteristics, types and purpose will be given.
Scope of application
Complete switchgears (switchgear) are devices consisting of switchboards, which include:
- devices for starting and controlling electrical appliances;
- protection devices;
- current measuring devices;
As well as other additional components, assembled and ready to go.
The main purpose is to receive and further distribute electricity in three-phase networks with a network operating frequency of 50 Hz and voltage above 1000 V.
Complete switchgears (switchgear) are divided into two types: outdoor and indoor installation. For indoor installation is placed in buildings or in the premises. Such devices are assembled with a busbar system. When used for operating voltages above 35 kV, air insulation is used; in networks, the voltage of 110 kV is SF6 insulated.
As a rule, in modern switchgear they use high-voltage vacuum circuit breakers as a protection and switching device , but there are more obsolete installations in which oil circuit breakers are installed .
Switchgear cabinets 6 are made for outdoor installation and are divided into two types according to design: rolling-out, in which all parts and assemblies are mounted on a special panel, and stationary, where all parts and assemblies are installed for a long service life.
Installation of an external installation
Outdoor switchgear must be prepared for installation, so the first thing to do is lay the foundation. Cells are moved in packaged form before all devices are installed. After that, the carts are unpacked and rolled out of the housing in which the switching equipment is installed. Set the cells according to the layout plan. Installation begins with extreme. After making sure that the cabinet is installed correctly, install the following. The important thing is that the cells should not be at an angle.
And for the installation of overhead lines on the roof, brackets are installed. It is also necessary to install local lighting near each cell. High-voltage cable lines with end sleeves are fixed to the terminals of the switchgear in the rear cabinet door. After that, the outdoor switchgear is ready for operation.
Design
Designed for complete switchgears (switchgear) for a voltage of 6/10 kV, should ensure the normal functioning of all elements installed in it. The switchgear is outwardly similar to large steel cells, inside of which switching, protective and auxiliary devices are mounted. The outer coating of the cell is made of steel sheets, this is done to increase the structural strength and protect against short-circuit current of other devices located nearby.
Switchgear cabinets 6 are equipped with special local heating, due to which current-measuring devices work normally in winter.
Specifications and Switching Ability
The switchgear (switchgear) 10 kV has the following nominal data:
- operating voltage of the network - 6, 10, 35, 110 kV;
- industrial operating frequency of the network - 50 Hz;
- operating current - 630 A;
- shutdown current - 12.5, 20, 25, 35, 40 kA;
- insulation - air;
- type of switches - vacuum;
- type of transformer current - TOLK-6;
- type of power transformer - TM-25;
- drive type - electric.
Switchgear stability of the switchgear is determined based on the parameters of the equipment, which is built into the circuit breaker with the drive installed on it. The switching equipment that is installed on the switchgear should work normally at rated loads and withstand test cycles at high shutdown currents that are installed in the technical specifications of the indoor units.
Retractable element and degree of protection
The retractable element on which the switching equipment is installed can be transmitted either manually or mechanically. At the same time, such a trolley should go along smooth surfaces, since it has a rather large mass.
All switchgear cabinets should be easy to use and designed for comfortable installation, repair and replacement of parts. In most switchgear cabinets, when the retractable carriage is rolled out of the cell to the working position, the openings to the fixed disconnecting contacts of the main circuit are locked with special shutters.
Depending on the type of application, there are different types of installations. Switchgear must fulfill the requirements of eclectic and mechanical strength of the structure, insulation and resistance to aggressive operating conditions. KRU placement categories:
- U3 - designed to work in rooms with natural air circulation;
- U4 - designed for rooms with artificial climatic conditions.
The design of the switchgear should ensure stability during vibrations that occur during switching on and off of high-voltage switches, as well as when moving the installation. At the same time, all devices must work properly, and the relay protection does not work during operation at nominal rates.
I can make switchgear for different climatic conditions using local heating or cooling.
Exploitation
When operating the switchgear, it is necessary to arrange technical inspection and maintenance of equipment located in the cell in a timely manner, as well as eliminate malfunctions.
Observation of the operation of the equipment is carried out by electricians on duty or the personnel who operate the installation. According to modern safety requirements, one person is not allowed to work with electrical installations, so at least two are needed when working with switchgear.
Workers who repair the installation should be trained and have a tolerance group of at least IV, and should also be aware of the equipment located in the switchgear and represent the work of individual parts of the electromechanisms.
Installation with operating voltage up to 35 kV
BM-4 series high-voltage switchgears are used to transmit electricity in three-phase current networks with an industrial frequency of 50 Hz and an operating voltage of 35 kV.
The switchgear cell is a structure sheathed with galvanized steel, the sheets of which are connected by a welded or riveted method. Inside, high-voltage switches, voltage transformers, switching equipment, measuring instruments and a disconnector are installed.
These switchgears are designed for two-way service. When installed in small-sized structures, a modified switchgear with one-sided service is produced. To maintain the temperature regime in the cells there are blinds. Also, to relieve excess pressure, which may appear in the event of emergency operating conditions or short-circuit currents, breakable valves are installed on the roof of the cell.
The device brand K-63
The switchgear of the K-63 brand is created from a metal case rigidly fixed to the supports, inside of which there is all the protective, switching and transformer equipment. Complete switchgears of the KRU K-63 type, like the rest, are designed to transmit and distribute electric current in three-phase networks, with an industrial frequency of 50 Hz and with an operating voltage of 6 kV.
A feature of K-63 switchgear is that it can be used as a transformer device. The main switching devices of K-63 are modern high-voltage BB / TEL switches with the use of electromechanical relays or microprocessor protection.
K-63 cells are designed for indoor installation, and the transformer can be located outdoors. K-63 is assembled with a single busbar system, the electricity to which is supplied through the high-voltage input cells to the switchgear that are located on the roof.
The device brand K-594: advantages
Switchgear switchgears of the K-594 brand, like all of the above installations, are used in networks with a voltage of 6-10 kV and a network operating frequency of 50 Hz.
As a rule, K-594 switchgears are used at transformer substations, power plants, agricultural facilities and railway transport. The switchgear KRU-594, the price of which depends on the supplier and the region of purchase, is excellent for connecting high-voltage motors and other electric machines. The main advantages of switchgear are:
- all electromechanisms are assembled in one cell and equipped at the factory;
- Switchgear increases the safety of the installation itself, as well as the working staff;
- all the most complex elements are mounted on a rolling trolley, which reduces the complexity of equipment maintenance work;
- switchgear cells are not bulky, so they significantly save space in the room.
The K-594 series switchgear (KRU) has technical characteristics that can change in case of increase or decrease in the rated nominal indicators of consumers to which the switchgear will be connected.
Conclusion
Switchgear is a reliable way to connect consumers, as it has high reliability and ease of use, as well as ease of maintenance and repair. They have earned their popularity in the world market as reliable power transmission equipment.