Abstract: “Conservation of Energy and Reduction of Energy losses requires condition monitoring and optimum utilization of substation equipments, in which HV Isolators are important component. Characteristics of thermal, mechanical, electrical environmental are all inter related in an electrical apparatus. So and so with respect to electrical isolator /disconnector which is widely employed in electrical network of power system. The isolator is a device to make or break electrical network at intended locations in the electrical lines. The mechanical operation is essential for proper functioning to connect or disconnect the circuit at planned time with safety and optimal performance. The mechanical operation is governed by proper thermal expansion and contraction of conductors present at fixed assembly and movable assembly. In this aspect it is imperative that isolator/ disconnector functions efficiently both by thermal and mechanical aspects besides electrical insulation co-ordination. In this back”

Keywords: Isolator/ disconnector, electrical equipment, temperature, thermal performance, thermal mapping, electrical network