An article allows you to instantly understand the internal structure of the Distribution Ready Board!
The composition of Distribution Ready Board is mainly divided into two parts. A complete set of components, namely, the shell of the Distribution Ready Board and its related accessories. 2. Electrical components and relevant accessories, i.e. circuit breakers and their required accessories.
The cabinet is composed of the following parts:
1、 Circuit breaker: it is not only a switch, but also the main component of the distribution cabinet. Circuit breakers are commonly used Leakage switch Dual power automatic transfer switch.
1. Circuit breaker:
A. Concept of circuit breaker:
The circuit breaker, that is, the air circuit breaker, makes connection, disconnection and carries the rated working current, short circuit, overload and other fault currents in the circuit, and can quickly disconnect the circuit and provide reliable protection in the case of overload, short circuit, undervoltage and other conditions of the line and load. The design types of the dynamic and static contacts and contact rods of the circuit breaker are various, but the main purpose is to improve the breaking capacity of the circuit breaker. At present, the current limiting principle of limiting the peak value of short-circuit current during breaking by using a certain contact structure has an obvious effect on improving the breaking capacity of circuit breakers, and is widely used.
B. Working principle of circuit breaker:
Automatic circuit breakers, also known as low-voltage circuit breakers, can be used to connect and disconnect load circuits, and also can be used to control infrequently started motors. Its function is equivalent to the sum of some or all functions of knife switch, overcurrent relay, voltage loss relay, thermal relay, leakage protector and other electrical appliances. It is an important protective appliance in low-voltage distribution network.
Automatic circuit breaker has many advantages, such as multiple protection functions (overload, short circuit, undervoltage protection, etc.), adjustable action value, high breaking capacity, convenient operation, safety and so on, so it is widely used at present.
2. Leakage protection switch:
A. Leakage protection switch concept:
It has the function of leakage protection. When people touch electrified power, they will trip and ensure personal safety. It is the main function of leakage protector; If the electrical equipment is poorly insulated and leaks electricity to the shell, the leakage protector will also trip to avoid electric shock caused by human touch. 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. In the figure, LH is a zero sequence current transformer, which is composed of an iron core made of permalloy and a secondary coil wound on the annular iron core. The phase line and neutral line of the power supply pass through the circular hole to become the primary coil of the zero sequence transformer. The rear outgoing line of the transformer is the protection range.
C. Function of leakage protection switch:
When electric leakage or grounding fault occurs to electrical equipment or lines, the power supply can be cut off before people touch it. 2. When the human body touches a charged object, it can cut off the power supply within 011s, so as to reduce the damage of current to the human body. 3. It can prevent fire accidents caused by electric leakage.
