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What is a high voltage switchgear?

Nov 22, 2018
Cooper Tulip Contact Of High Voltage VCB Meet Electric IEC Standard.jpgHigh-voltage switchgear refers to the rated voltage of 1kV and above, mainly used for breaking and closing the conductive circuit. It is the high-voltage switch and its corresponding control, measurement, protection, regulating device and accessories, housing and support components and their electrical The general term for the combination of mechanical and mechanical connections is an important control device for switching on and off circuits, cutting and isolating faults. High-voltage switchgear generally includes high-voltage circuit breakers, isolating switches, load switches, fuses, and high-voltage switchgear.

When the equipment is in normal operation, the high-voltage circuit breaker of the high-voltage switchgear is mainly used to switch on or off the load current; when the equipment is faulty or severely overloaded, the high-voltage circuit breaker can be used to automatically and quickly cut off the fault current (with relay protection) Device) to prevent accidents. The high-voltage circuit breaker is mainly composed of a conductive circuit, an arc extinguishing chamber, a casing, an insulating support, an operation and a transmission mechanism.

In high-voltage switchgear, the load switch is an electrical device dedicated to switching load currents on and off; when a trip unit is installed, it can automatically trip under overload conditions. But it only has a simple arc extinguishing device. Therefore, the short-circuit current cannot be cut off. In most cases, the load switch is connected in series with the high voltage fuse, and the short circuit current is cut by means of a fuse.

High-voltage fuses are a kind of protection device commonly used in high-voltage switchgear. The utility model has the advantages of simple structure, widely used in power distribution devices, and is often used as a protection circuit, a transformer and a voltage transformer. The high-voltage fuse consists of three parts: the melt, the metal-supporting contacts and the protective casing, which are connected in series in the circuit. If the circuit is overloaded or short-circuited, when the fault current exceeds the rated current of the melt, the melt is quickly heated and blown, thereby cutting off the current to prevent the fault from expanding.