Gas Insulated Switchgear for Medium Voltage Application

Modern day electrical installation call for equipment of the type “Install and forget”. This has been partially realized with the introduction of modern free technology of Vacuum Circuit Breakers (VCB). As a further improvement in this direction new concepts of switchaear are being introduced wherein the circuit breakers are made not only maintenance free from the switching furnctions performed but also making them immune to the climate and environmental conditions. With the introduction of VCB, maintenance requirements are considerably changed and thus, conventional forms of withdrawable circuit breakers which are primarily designed with the case of maintenance in mind have become redundant. This has made it possible to develop a type of switch panel whose switching elements need no accessibility and has enabled a hybrid of Vacuum and SF6 technology to create a new generation of compact and maintenance-free gas insulated switchgear. With this concept in mind, a technology was introduced in 36 KV voltage class, i.e., gas insulated sWitchgear panel type GVM36 using well proven vacuum Interrupter and SF6 gas insulation. This reduces maintenance requirement and risk of break-down to a very minimum level. The stringent reliability and safety requirement to be met by medium voltage switchgears necessitate the new design to be effective only with time tested switchgear concept. This has been achieved in this new breed of GVM36 switchgear by using the following: - The proven Vacuum Interrupter with its operating mechanism. - Use of SF6 Gas well established in all high voltage equipment. - Panels of modular design.