High Voltage Earthing Switch

High Voltage earthing Switch made in China. SanGao’s switch is used to shut off short circuit current and has a certain short circuit closing capacity as well as dynamic thermal stability. Since it does not need to break load current and short circuit current, there is no arc extinguishing device. The lower end of the earthing switch is usually connected to the grounding point through a current transformer. The current transformer can provide signals for relay protection.

There are many structures of earthing switches. Including single pole, double pole and three pole earthing switches. Single pole earthing switches are only used in neutral point grounding systems. Double pole and three pole structures are used in neutral point ungrounded systems and share an operating mechanism.

The High Voltage earthing Switch in the switchgear is used to ground the remaining charge after the power line is disconnected from the power supply. Even if the circuit breaker and the isolator cut off or open the circuit, the residual charge will still remain in the circuit. The earthing switch is usually used to release the charge.

The High Voltage earthing Switch has a fast acting closing mechanism. They can protect technicians and workers when abnormal currents occur. They are designed to withstand short circuits; they can also be motorized. For example, high voltage earthing switches and high speed earthing switches. The earthing switch in the substation is able to generate a short circuit, thereby protecting other electrical equipment from damage. It is used in conjunction with a variety of high voltage switchgear and can also be used as a protective device when overhauling high voltage electrical equipment.

The earthing switch, circuit breaker, and isolating switch are all connected in the ring main unit (RMU). If the circuit needs to be disconnected or disconnected for maintenance or other reasons, the correct operating sequence of these three devices (earthing switch, circuit breaker, and isolating switch) must be followed. If the correct steps are not followed, not only will the circuit and equipment be damaged, but you will also be put in danger. For a perfect installation of these components, you can contact Elecspare, a gis switchgear manufacturer, to provide reliable insulating media for your equipment.

Earthing switches and disconnectors are often combined into one device. In this case, the disconnector is equipped with an earthing switch in addition to the main contacts, which is used to ground one end of the disconnector after opening. The main contacts and earthing switches are usually mechanically interlocked, so that the earthing switch cannot be closed when the disconnector is closed, and the main contacts cannot be closed when the earthing switch is closed.

Earthing switches can be divided into open and closed types. The conductive system of the open earthing switch is exposed to the air like the disconnector; the conductive system of the closed earthing switch is enclosed in live SF6 or insulating media (such as oil).

The focus of the substation earthing switch is far less than that of the public, and it is not as safety oriented as the low voltage system. It focuses more on power supply reliability, protection reliability, and the impact on equipment in the event of a short circuit. Since the current path is mainly blocked by grounding, only the amplitude of the most common phase to ground short circuit is affected by the choice of grounding system.