Gas Insulated Switchgears (GIS)

Sulfide Hexafluoride, SF₆, is widely used as dielectric media in many mid and high voltage power breakers.

For the producers of mid voltage switchgears, Telstar supplies machines that integrate several operations in one single unit.

Air evacuation

In order to have a high purity of SF₆ gas inside the GIS, the air must be removed till low pressures.

Mechanical resistance

Since many GIS do not stand vacuum, nor pressure, inside, the air evacuation inside the GIS must be done simultaneously with a pressure reduction outside the GIS, in a way that the maximum differential pressure is never exceeded.

Leak detection

Before filling the SF₆ gas it is necessary to verify that the GIS box is completely tight. The leak detection is performed by means of Helium and mass spectrometry and allows to find leaks smaller than 0,1% of the SF₆ charge per year.

SF₆ gas filling

The SF₆ filling is done in a precise way, and is measured in several ways.

SF₆ gas emissions

Telstar's plants do not release SF₆ into the atmosphere

SF₆ recovery

The machine can be used for fast and effective recovery of the SF₆ gas content of any GIS that needs repair. Recovery rate is higher than 99,99%.

Telstar Technologies is an approved machines supplier for the major GIS makers, worldwide.