How much do you know about the internal structure of low voltage distribution box!?
In the popular sense, the power distribution cabinet is a cabinet integrated with electrical components for power distribution. The function of the power distribution cabinet is to distribute and control the electrical equipment. In case of overload, short circuit and leakage, the power distribution cabinet can also provide power-off protection.
Although the distribution cabinet is used in residential buildings, schools, hospitals and other domestic power distribution control, but the smaller size of the distribution cabinet can be hidden in the wall, so we rarely see the distribution cabinet in our daily life. Generally speaking, power distribution cabinet is often seen in enterprise workshops, such as lighting distribution box, power distribution box, etc.
Classification of distribution cabinet
When the power distribution cabinet is used in large power supply system, it will be divided into different levels for better power distribution control.
Generally speaking, there will be level 1, level 2 and level 3 distribution equipment in the power supply system.
Level 1 power distribution cabinet is the power distribution center of the power supply system, which will be installed in the substation, responsible for the distribution of electric energy to level 2 power distribution cabinet. The function of level 1 distribution cabinet requires higher electrical parameters, so the structure of level 1 distribution cabinet is more complex and the output circuit capacity is larger.
The secondary distribution cabinet undertakes the power distribution of the primary distribution cabinet and distributes it to the nearest load. The secondary distribution cabinet is divided into power distribution cabinet and motor control center. The application parts of the two are opposite. The power distribution cabinet is used in the parts with less circuits and scattered loads, while the motor control center is used in the parts with more circuits and concentrated loads.
The low-level distribution cabinet is the lighting distribution cabinet and the power distribution cabinet. Their layout is relatively scattered and their capacity is small. They are responsible for controlling the low-level load distribution.
Application of distribution cabinet
Switchgear is a complete set of switchgear and control equipment, which is used as power center and main power distribution device. It is mainly used for control, monitoring, measurement and protection of power lines and main electrical equipment. It is usually set in substation, distribution room, etc.
It is convenient for management and maintenance when circuit failure occurs.
Distribution box and distribution cabinet, distribution board, etc. are complete sets of equipment for centralized installation of switches, instruments, etc.
There are two kinds of commonly used distribution boxes: wooden and iron. Now the power consumption is very large everywhere, so the iron is used more.
It is convenient to stop and transmit power, and plays the role of measuring and judging the power stop and transmission.
The distribution cabinet is mainly composed of two parts
Is a complete set of components, that is, distribution box shell and related accessories.
Second, electrical components and related accessories, that is, air switch and its required accessories.
The cabinet consists of the following parts
1. Circuit breaker
That is, the switch is the main component of the distribution cabinet, commonly used air switch, leakage switch, dual power automatic transfer switch.
1. Air switch: air circuit breaker is used for connecting, breaking and carrying rated working current, short circuit, overload and other fault current in the circuit, and can quickly break the circuit in case of overload, short circuit, undervoltage and other conditions of line and load, so as to provide reliable protection.
2. Leakage protection switch: it not only has the function of leakage protection, but also can trip when people touch the live line to ensure personal safety, which is the main function of leakage protector.
3. Dual power automatic transfer switch: the dual power automatic transfer switch is an automatic transfer system of one-out-of-two power supply.
2、 Surge protective device
Also known as lightning protector, it is an electronic device that provides safety protection for various electronic equipment, instruments and communication lines.
When the electrical circuit or communication line suddenly produces peak current or voltage due to external interference, the surge protector can conduct shunt in a very short time, so as to avoid the damage of surge to other equipment in the circuit.
Identification of cables in distribution cabinet
The cables of power distribution cabinet are complex. Each cable is connected to different component units, and its functions are different. It is impossible for the installation and operation maintenance personnel to memorize various equipment and lines. In order to facilitate the installation and inspection, it is necessary to make the identification for each cable.