Section Insulator

Railway overhead lines must be electrically isolated along its way for several reasons such as, allowing electrically insulated safe working sites, splitting the electrical circuit for different energy sources (electrical substations), etc. In order to satisfy these requirements section insulators are specified considering characteristics such as : voltage, creepage distance, electrical parameters, mechanical tension and speed in line. A section insulator is a device installed in the catenary system for electrical separation of two electrical feeds while allowing for the passage of a vehicle pantograph, such as in a crossover between two adjacent tracks. The SI is designed to take into account all of the required electrical clearances necessary for the system voltage. This type of sectionalizer is often called a section insulator, effectively “chopping up” the entire distribution circuit into smaller sections which can then be maintained or closed off as required.