Do you really have a comprehensive understanding of low voltage switchgear?

source：jinzhong transmission and distribution   time：2020-11-24   Number of hits：1183of hits

1、 What is switch cabinet

Jinzhong Power Transmission and distribution sharing to the switch cabinet is a kind of electrical equipment. The external line of the switch cabinet enters the main control switch in the cabinet first, and then enters the sub control switch. Each branch circuit is set according to its needs. One or more low-voltage switchgear and related control, measurement, signal, protection, regulation and other equipment, the manufacturer is responsible for the completion of all internal electrical and mechanical connections, which are completely assembled with structural components. In the process of power transmission, switch on and power switch are the main functions of power switch. The components in the switch cabinet are mainly composed of circuit breaker, disconnector, load switch, operating mechanism, transformer and various protection devices.

2、 Structure and composition classification of switch cabinet

In order to protect the personal and equipment safety, the switch cabinet is divided into several compartments

Busbar chamber: including horizontal busbar chamber and vertical busbar chamber functional unit room (switch compartment)

Cable outlet room: including cable room and secondary equipment room

2.1 main components of switch cabinet

Cabinet body: the shell framework and internal installation and support parts of the switch cabinet. Bus bar: a low impedance conductor that can be connected with several circuits separately

Functional unit: all electrical equipment and mechanical parts (including incoming line unit and outgoing line unit) for the same function

2.2 incoming line (plug-in bus duct or cable)

Upper line; lower line; side line; rear line

2.3 outlet mode (plug-in bus or cable)

The front outlet (top or bottom) can be installed against the wall

The rear outlet (top or bottom) cannot be installed against the wall

2.4 bus classification:

Main bus (horizontal bus): the bus connecting one or more distribution buses and or incoming and outgoing units

Distribution bus (vertical bus): a bus in a frame unit, which is connected to the main bus and supplies power to the outgoing unit

2.5 functional unit classification

Fixed type: the main circuit can only be connected and disconnected when the switch cabinet is powered off

Movable type (fixed separation type): it can be safely disconnected or connected from the main circuit when the main circuit is charged, with connection and removal positions

Draw out type: when the main circuit is charged, it can also be safely disconnected or connected from the main circuit, with connection, test, separation and removal position

3、 Classification of low voltage switchgear

GCS cabinet:

GCS type low-voltage draw out switch cabinet is used in three-phase AC frequency of 50 Hz, rated working voltage of 400 V (690V), rated current of 4000 a and below. It is used as power, power distribution and motor centralized control, capacitor compensation in power supply system. It is widely used in power plants, petroleum, chemical, metallurgy, textile, high-rise buildings and other places, as well as large-scale power plants, Petrochemical system and other places with high degree of automation and computer interface are required