What is the internal structure of the distribution box?

source：jinzhong transmission and distribution   time：2020-11-24   Number of hits：847of hits

"Distribution box", also known as distribution cabinet, is a general term for motor control. According to the requirements of electrical wiring, the switchgear, measuring instruments, protective appliances and auxiliary equipment are assembled in a closed or semi enclosed metal cabinet or panel to form a low-voltage distribution device. In normal operation, the circuit can be connected or disconnected by manual or automatic switch. In case of fault or abnormal operation, the circuit is cut off or the alarm is given with the help of protective appliances. With the help of measuring instrument, various parameters in operation can be displayed, and some electrical parameters can be adjusted to prompt or send signals to deviate from normal working state. The following by Guizhou power distribution equipment to understand.

The purpose of the distribution box is easy to manage, and it is convenient for maintenance in case of circuit failure. Distribution box and distribution cabinet, distribution board, etc., is a complete set of equipment for centralized installation of switches, instruments and other equipment. Commonly used distribution box has two kinds of wood and iron plate, where the power consumption is very large, so iron is still used more. The purpose of the distribution box: of course, it is convenient to stop and transmit power. It plays a role in measuring and judging the power stop and transmission.

The composition of distribution box is mainly divided into two parts: one is a complete set of components, that is, the shell of distribution box and its related accessories. 2、 It is electrical components and related accessories, namely air switch and its required accessories.

The cabinet is composed of the following parts: 1. Circuit breaker circuit breaker: both switch, is the main component of the distribution cabinet, commonly used air switch, leakage switch, double power automatic transfer switch.

1. Air switch: A. concept of air switch: air switch is air circuit breaker, which can make and break the circuit and carry 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 and undervoltage of the line and load for reliable protection. There are various design types of dynamic contact, static contact and contact rod of circuit breaker, but the main purpose is to improve the breaking capacity of circuit breaker. At present, the current limiting principle of limiting the peak value of short-circuit current when breaking with a certain contact structure has obvious effect on improving the breaking capacity of circuit breaker, and is widely used. B. Working principle of air switch: automatic air switch, also known as low-voltage circuit breaker, can be used to connect and break the load circuit, and also can be used to control the motor starting infrequently. Its function is equivalent to the total function of knife switch, over-current relay, loss of voltage relay, thermal relay and leakage protector. It is an important protective device in low-voltage distribution network. Automatic air switch has a variety of protection functions (overload, short circuit, under voltage protection, etc.), adjustable action value, high breaking capacity, convenient operation, safety and other advantages, so it is widely used.

2. Leakage protection switch: a. the concept of leakage protection switch: it has the function of leakage protection. When people touch the live line, it will trip to ensure personal safety. If the insulation of electrical equipment is not good, the leakage protector will also trip to avoid touching electric shock. At the same time, it has current on-off function, overload protection and short-circuit protection function. B. Working principle of leakage protection switch: working principle diagram of leakage protector. LH is a zero sequence current transformer. It consists of a permalloy core and a secondary coil wound on the annular core. The phase line and neutral line of the power supply pass through the round hole and become the primary coil of the zero sequence transformer. The rear outlet of the transformer is the protection range.