What is the definition and major categories of low-voltage electrical appliances?

Last Update Time: 2019-05-23 11:55:08

1.The definition of low-voltage electrical appliances


Low-voltage electrical equipment refers to electrical equipment that operates in circuits with AC voltage less than 1200V and DC voltage less than 1500V, functions as on/off, protection, control or regulation, and uses electrical energy to control, protect and regulate non-electrical processes and non-electrical devices. Electrical Equipment. Most of the load on the power system is supplied through low-voltage electrical appliances. Most of the various production machinery and equipment of power users are powered by low voltage. In the huge low-voltage power distribution system and low-voltage power system, a large number of low-voltage electrical appliances for control and protection are required.


A low-voltage electrical appliance is a component or device that can manually or automatically turn the circuit on or off according to external signals and requirements to switch, control, protect, detect, change and adjust the circuit or non-electrical object. According to the working voltage of the control electric appliance, it can be divided into two categories: high-voltage control electric appliance and low-voltage control electric appliance, with the boundary of AC 1200V and DC 1500V. In general, low-voltage electrical appliances can be divided into two major categories of distribution electrical appliances and control electrical appliances, and are the basic components of complete electrical equipment. In the industrial, agricultural, transportation, defense, and people's electricity sectors, most use low-voltage power supply, so the quality of electrical components will directly affect the reliability of low-voltage power supply systems.

 

2.Low-voltage electrical classification


1) According to the action mode can be divided into:

(1) Manual electrical appliances--Electrical appliances that rely on direct external operation to switch, such as knife switches and push button switches.


(2) Automatic electrical appliances--Electrical appliances that operate automatically by commands or physical quantities, such as contactors and relays.


2)According to the use can be divided into:

(1) Low-voltage control electrical appliances--mainly play a controlling role in low-voltage power distribution systems and power equipment, such as knife switches and low-voltage circuit breakers.


(2) Low-voltage protection appliances - mainly play a protective role in low-voltage distribution systems and power equipment, such as fuses, thermal relays, etc.


3) According to the type can be divided into:

Knife switches, blade switches, fuses, low voltage circuit breakers, contactors, relays, mains and automatic switches.