Low voltage (LV) switchgear is, generally, any electrical switchgear that is rated up to 1 kV. This includes various devices, such as, low voltage circuit breakers, load break switches, disconnectors, fuses, earth leakage, circuit breaker, MCBs, MCCBs, etc. LV switchgear are commonly used in LV distribution boards. Circuit breakers incorporate low voltage electrical protection in the form of either thermal-magnetic devices or residual-current-operated tripping devices.
LV switchgear are used in applications, such as motor feeder for protection against over load, short circuit, over current up to locked rotor condition and single phasing. Further they are used as protection for industrial feeder, such as electroplating baths, ovens, etc. and for protection of AC lighting loads. Generally, low voltage switchgear are used to supply electricity for critical power and process applications, such as, those found in heavy industry, manufacturing, mining, metal work, petrochemical, pulp and paper, water treatment, datacentres and healthcare.
The main functions of LV switchgear are electrical protection, electrical isolations of sections of an installation, and local or remote switching. In addition to this, they are required to perform other functions, such as, over-voltage and under-voltage protection. The purpose of using the LV switchgear is to try and prevent or at least reduce the damage caused by short-circuit currents or by overloading and insulation failures and to isolate the faulty portion of the circuit from the rest of the installation.