Circuit breaker refers to the switch device that can close, carry and open the current under the normal circuit condition and can close, carry and open the current under the abnormal circuit condition within the specified time. It has many types and wide applications. Let's take a look at its classification and some representative products.
(1) According to the number of poles, there are single pole, two pole, three pole and four pole.
(2) According to the way of installation, there are plug-in type, fixed type and drawer type, etc.
(3) According to the scope of usage, there are high voltage circuit breaker and low voltage circuit breaker. The demarcation line between high voltage and low voltage is vague. Those above 3KV are generally called high voltage electrical appliances.
It is used for short circuit and overload protection of lighting distribution circuit.
It is used for short circuit overload and leakage protection in grounding system. The normal operation fault protection of the circuit breaker makes the phase line and the neutral line in the off position of the circuit breaker, so as to avoid the electrification of the neutral line in case of fault. In the process of making and breaking operation, the neutral line has priority in connection and breaking delay. It has short-circuit current limiting function and high rated short-circuit breaking capacity. With overload protection, short-circuit leakage and voltage protection device, the protection function is complete. The wiring is also convenient and reliable.
The full-automatic overvoltage and undervoltage time delay protector is a new generation product. The protector is reasonably designed and assembled with imported components and domestic famous brand components. The product can switch the power supply quickly and reliably under high-voltage impact and undervoltage to protect household appliances. When the voltage returns to the normal value, it can automatically connect the circuit and restore the power supply after the delay, which can effectively protect the impact of the electric appliance when it is powered on at the moment of power supply. All functions are automatic, safe and fast. No special personnel is needed for operation.
It is used for short circuit and overload protection in industrial power distribution system. Its rated current is 63A-125A. It has high rated short-circuit breaking capacity, with short-circuit current limiting structure. The protection function is complete with overload and short-circuit protection device. The wiring is safe and reliable, adopting the "frame" wiring structure. The function expansion is simple, safe and reliable. It can be equipped with various accessories, such as leakage release, auxiliary contact, alarm contact, etc.
EPD plug-in type adopts the same working principle and selection criteria as fixed surge protection. It protects the surge affected by indirect lightning and direct lightning or other instantaneous overvoltage.
It is mainly used for AC 50Hz or 60Hz rated voltage up to 660V and below for long-distance connection and breaking circuit. It can be combined with corresponding specifications of thermal relay or electronic protector to form electromagnetic or electromechanical integrated motor starter.
The molded case circuit breaker is one of the new type circuit breakers designed and developed by the international advanced technology. The rated insulation voltage of the circuit breaker is 800V, which is suitable for the distribution network circuit with AC 50Hz and 60Hz, rated working voltage to 690V and rated working current from 6A to 1250A. The circuit breaker is used to distribute electric energy and protect the line and power equipment from overload, short circuit, undervoltage and other faults. It can also be used as the infrequent starting of the motor and the protection of overload, short circuit and undervoltage. The circuit breaker is an ideal product with small volume, high breaking height and short flashover.
It is used to provide indirect contact protection for people, and prevent fire hazard caused by equipment insulation damage and ground fault current. It can also be used for short circuit of distribution electric energy, overload of protection line and power supply equipment, as well as infrequent line switching and infrequent motor starting. The circuit breaker of this series is three-phase. If any phase is missing, the leakage protection module of the circuit breaker can still work normally. The rated residual action current and the maximum disconnection time can be adjusted on site according to the actual situation.
The circuit breaker is the most widely used one in high-voltage switchgear, which plays an isolation role in the circuit. Its working principle and structure are relatively simple. But due to the large amount of application and high requirements of working reliability, it has a great impact on the design, establishment and safe operation of substations and power plants.
Two power supplies are used to ensure the reliability of power supply. A product can switch between two power supplies reliably. The product has two switching functions, auto switch and auto recover. This is a manual change-over switch with novel design. It is safe and reliable, with high degree of automation and wide range of application.
It is mainly used to distribute electric energy and protect lines and power equipment from overload, short circuit, undervoltage, single-phase grounding and other faults. The circuit breaker has a variety of intelligent protection functions, which can be used for selective protection, with accurate action, avoiding unnecessary power failure and improving power supply reliability and safety.