Classification of low-voltage electrical appliances
There are many types of low-voltage electrical appliances, and there are many ways to classify them.
I. According to the method of action, it can be divided into
( 1 ) Manual electrical appliances - electrical appliances that rely on external force to operate directly for switching, such as knife switches, push-button switches, etc.
( 2 ) Automatic electrical appliances -- electrical appliances that operate automatically based on instructions or changes in physical quantities, such as contactors and relays.
II. According to usage, it can be divided into
( 1 ) Low-voltage control electrical appliances - mainly play a control role in low-voltage power distribution systems and power equipment, such as knife switches, low-voltage circuit breakers, etc.
( 2 ) Low-voltage protection electrical appliances - mainly play a protective role in low-voltage power distribution systems and power equipment, such as fuses, thermal relays, etc.
III. Classified by type
Knife switches, knife-type changeover switches, fuses, low-voltage circuit breakers, contactors, relays, master control devices, and automatic switches, etc.
What are low-voltage electrical components?
1. Knife switch
A knife switch is a simple and easy-to-operate electrical appliance, commonly used in circuits where connection and disconnection are relatively simple.
2. Automatic air conditioning
Automatic air circuit breakers, also known as air circuit breakers, are a commonly used type of low-voltage protective electrical appliance that can provide protection against short circuits, overloads, and undervoltage.
3. Changeover switch
A changeover switch, also known as a combination switch, is an electrical appliance with multiple contacts that can be used for forward and reverse control.
4. Button
A button is a control electrical device that is manually operated and has an automatic reset function. Buttons are commonly used in control circuits to connect and disconnect power. There are many types of buttons; below are some common ones.
5. Low-voltage circuit breaker
A low-voltage circuit breaker is an electrical appliance with overcurrent protection, commonly used in households to control the power supply line. It automatically disconnects when the current exceeds a specified value and can be manually reset.
6. Fuse
A fuse is one of the simplest and most effective protective electrical appliances, serving as a short-circuit protection device in a circuit. In the event of a short circuit or severe overload, the fuse wire in the fuse will melt instantly, cutting off the power supply.
The role of low-voltage electrical appliances
Low-voltage electrical appliances can automatically or manually change the state and parameters of the circuit according to the requirements of operating signals or external field signals, so as to realize the control, protection, measurement, indication and regulation of the circuit or the controlled object .
The functions of low-voltage electrical appliances include:
Control functions, such as the elevator's vertical movement, automatic switching between fast and slow speeds, and automatic stopping at floors.
In terms of regulation, low-voltage electrical appliances can adjust some electrical and non-electrical quantities to meet user requirements, such as adjusting the throttle of a diesel engine, regulating room temperature and humidity, and automatically adjusting illuminance .
It has a protective function, which can automatically protect equipment, the environment, and people according to the characteristics of the equipment, such as overheat protection of motors, short circuit protection of power grid, and leakage protection.
Indicative functions: Utilizing the control and protection functions of low-voltage electrical appliances, the operating status of equipment and the working condition of electrical circuits are detected, such as insulation monitoring and protection tripping indication.
