What is high voltage switchgear？

High voltage switchgear refers to electrical appliances with a rated voltage of 1kV and above, and is mainly used to break and close conductive circuits. It is a high-voltage switch and its corresponding control, measurement, protection, adjustment device, accessories, housing and support and other components and their electrical The general term for the connection with the machinery is an important control device for connecting and disconnecting circuits, removing and isolating faults.

High-voltage switchgear generally includes high-voltage circuit breakers, isolating switches, load switches, fuses, and high-voltage switch cabinets.

1. High voltage circuit breaker

During the normal operation of the equipment, the high-voltage circuit breaker is mainly used to switch on or cut off the load current; when the equipment fails or is seriously overloaded, the high-voltage circuit breaker can be used to automatically and quickly cut off the fault current (with the help of a relay protection device). Prevent accidents. The high-voltage circuit breaker is mainly composed of conductive circuit, arc extinguishing chamber, shell, insulating support, operation and transmission mechanism, etc.

2. High voltage isolation switch

(1) Purpose

The main purpose of the high-voltage isolating switch is to isolate the high-voltage power supply and form a visible interval to ensure that other electrical equipment can be safely inspected and repaired. But because the isolating switch has no arc extinguishing setting, it can't switch on and off the load current, and can only switch on or off a small current.

(2) Type
Isolation switches can be divided into two types according to the placement position, indoor type and outdoor type (60 kV and above voltage without indoor type): according to the number of stages, it can be divided into two types: single-stage and three-stage; according to structure, it can be divided into two-pillar There are three types: type, three-post type and V-shaped; according to the insulation situation, it can be divided into two types: ordinary type and reinforced insulation type; according to the grounding situation, it can be divided into two types: grounded switch and non-grounded switch. Isolating switches are generally open-type, but can also be customized into closed-type isolating switches under certain conditions.

3. High voltage load switch

(1) Purpose
In high-voltage power distribution devices, load switches are electrical equipment specially used to switch on and off load currents; when a trip device 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 a high-voltage fuse (generally RN type), and the short-circuit current is cut with the help of the fuse.

(2) Type
There are two types of high-voltage load switches, indoor type and outdoor type, with manual operating mechanism to work. It has an obvious open circuit gap and can also function as an ordinary high-voltage isolating switch.

4. High voltage fuse

(1) Purpose
High-voltage fuse is a commonly used protective electrical appliance. It has a simple structure and is widely used in power distribution devices, often used to protect circuits, transformers, voltage transformers and other equipment. The high-voltage fuse consists of three parts: the melt, the contact supporting the metal body and the protective shell, 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 will be quickly heated and blown, thereby cutting off the current to prevent the fault from expanding.

(2) Type
High-voltage fuses can be divided into indoor and outdoor types according to the place of use. The indoor type is generally made into a prescribed type, while the outdoor type is all made into a drop-out type (after the fuse is blown, the melt tube is automatically disconnected).

5. High voltage switch cabinet

(1) Purpose
6～35 kV high voltage switchgear is generally suitable for AC 50 Hz, 3～35 kV voltage power system, as electric energy receiving and distribution on, off and monitoring protection. It is made by the manufacturer in accordance with a certain wiring method to assemble the switching appliances, busbars, measuring instruments, protective appliances and auxiliary equipment of the same circuit in a closed metal cabinet and supply them to users in complete sets. This kind of equipment has the characteristics of compact structure and convenient use, so it is widely used in equipments such as controlling and protecting transformers, high-voltage lines and high-voltage motors.

(2) Type
High-voltage switch cabinets mainly include fixed type and handcart type. According to the different structure, it can be divided into three types: open type, closed type and semi-closed type; according to the different use environment. It can be divided into indoor and outdoor two types; according to the different operation modes, it can be divided into electromagnetic operating mechanism, spring operating mechanism and manual operating mechanism.