Complete switchgear (KRU)
KRU
Complete switchgear units (KRU) are a category of electrical installations that serve to receive and distribute electrical energy and current, but only of one specific voltage category.
The purpose of complete switchgear depends on their type and main classification. They are divided into:
To complete the partitioning tasks:
Switchgear units that have one busbar section, i.e. without division into sections; a less popular installation, since it has a number of disadvantages during direct operation;
Switchgear units that have two or more prefabricated busbar sections. This category of switchgear is produced in the form of several prefabricated sections that have their own power supply and load, and they are also connected to each other by a sectional switch.
Sectional switchgear units, which have a bypass device. Such installations are common on lines with voltage from 110 to 220 kV.
KRUE or complete switchgear with SF6 insulation. This is high-voltage equipment, which is designed for receiving, current distribution and transmission of energy in a three-phase current network with an alternating frequency of 50 Hz and a rated voltage of 110 kV. All gas-insulated complete switchgears are three-phase units that have a number of additional auxiliary devices.
By the number of existing busbar systems:
- with the presence of a single busbar system;
- with the presence of a double busbar system.
According to the structure of the scheme used:
By installation and placement location:
Complete outdoor switchgear units are a type of special devices whose power conductors are placed in open space, but they are not protected from external factors. The category of such installations also includes explosion-proof complete switchgear units of outgoing type of connection. Its main purpose is to receive and distribute electricity with voltage from 6 kV and frequency up to 50 Hz. Protects networks with isolated neutral. In rare cases, it can be mounted indoors or in the middle of mines.
Complete indoor switchgear units are a type of special devices that are mounted in closed rooms or power conductors protected from external factors by special type casings, including in KRUN cabinets. Such internal complete switchgear units 6, 10, 35 kV from the manufacturer are specially developed for operation in networks with a three-phase energy flow.
The choice of the required type of complete distribution units depends primarily on the type of production and its needs.
Production of complete switchgear and their areas of application
All complete switchgear units have general industrial purposes and are often used as distribution units at power stations and substations of large enterprises, subways, railways, and at mining enterprises of the oil and gas complex.
The cabinet of complete distribution devices with a voltage switch is divided into several basic sections, which have metal partitions for the purpose of isolation from each other. Four sections are always a storage for high-voltage equipment, and the fifth compartment of the relay type is low-voltage, and meters for recording the consumed electricity are also mounted on its doors.
Current transformers, earthing switches, fuses and limiters are installed in the busbar section to prevent overvoltage. Therefore, all cabinets are equipped with a vacuum voltage switch. The installation of switchgear is carried out based on the design features, main purpose and type of such installation.
