"Vacuum circuit breaker" is named for its high dielectric energy due to its arc extinguishing medium and the insulating medium of the contact gap after arc extinguishing; it has the advantages of small size, light weight, suitable for frequent operation, and no need for overhaul of arc extinguishing. The application in the power grid is more popular. The vacuum circuit breaker is an indoor power distribution device in a 3～10kV, 50Hz three-phase AC system, which can be used for protection and control of electrical equipment in industrial and mining enterprises, power plants and substations, especially suitable for oil-free and less For maintenance and frequent operation, the circuit breaker can be configured in the central cabinet, double-layer cabinet and fixed cabinet for controlling and protecting high-voltage electrical equipment.

Intelligent universal circuit breaker is used in AC power distribution network with 50Hz, rated voltage of 400V, 690V and rated current of 200A~6300A. It is mainly used to distribute power and protect circuit and power equipment from overload, undervoltage, short circuit and single phase. The fault of the grounding and other faults, the circuit breaker has a variety of intelligent protection functions, can be selectively protected, and the action is accurate, to avoid unnecessary power outages, improve power supply reliability.

Plastic case circuit breakers are generally used for power distribution and can also be used to protect motors. Under normal conditions, the circuit breaker can be used as infrequent switching of the line and infrequent starting of the motor.

The residual current operated circuit breaker can quickly cut off the faulty power supply in a very short period of time to protect the safety of personal and electrical equipment. The current action circuit breaker is suitable for AC 50Hz or 60Hz, rated voltage unipolar two-wire, two-pole 230V, three-stage/three-level four-wire, four-stage 400V, rated current to 60A, when the human body is exposed to electricity or the grid leakage current exceeds the regulations. When the value is exceeded, the residual current operated circuit breaker can be cut off quickly in a very short time.

The high-breaking miniature circuit breaker protects against overload and short circuit of electrical lines or equipment, and has power isolation. And with DC products, it is suitable for overload and short circuit protection of DC lines, and is widely used in telecommunications or electric locomotives.

The isolating switch is a switching device mainly used for "isolated power supply, switching operation, to connect and cut off small current circuits", and without arc extinguishing function. When the isolating switch is in the position, there is an insulation distance and a clear disconnection mark between the contacts in accordance with the specified requirements; in the combined position, it can carry the current under the normal loop condition and under abnormal conditions (such as short circuit) within a specified time. Current switching device. Generally used as a high-voltage isolating switch, that is, an isolating switch with a rated voltage of 1kV or more. Its working principle and structure are relatively simple, but due to the large amount of use and high reliability requirements, the design and establishment of substations and power plants are The impact of safe operation is large. The main feature of the isolating switch is that it has no arc extinguishing capability and can only divide and close the circuit without load current. The terms introduce the functions, features, types, applications, anti-error improvement, maintenance, and common problems of the isolating switch.