isolatorer

Isolatorer are devices used to provide electrical isolation and mechanical support in electrical power systems. They are designed to prevent current flow between energized parts and grounded or differently charged sections, and to withstand the mechanical stresses of mounting and weather. In many grids, isolators also function as disconnecting devices that can isolate a section of equipment for maintenance, while other insulators serve primarily as passive dielectric supports.

Common forms on overhead lines include pin insulators and suspension insulators, made from porcelain or glass, though modern installations increasingly use polymer composites for lighter weight and better pollution resistance. In switchyards or substations, post insulators support conductors and busbars. Isolating switches, or isolators, may be hinge-type, blade-type, or horizontal/vertical in configuration, and are operated to open or close circuits as part of protection schemes. They are designed to be opened only when the circuit is de-energized or properly interlocked to prevent unsafe operation.

Materials and performance: porcelain and glass insulators offer high dielectric strength but can be brittle and sensitive to weathering. Polymer insulators, typically silicone rubber over a composite core, provide lighter weight and hydrophobic surfaces that shed moisture, improving leakage performance in polluted or damp environments. Key design criteria include creepage distance, puncture voltage, mechanical load rating, and weathering performance under pollution, icing, and outdoor conditions.

Applications and maintenance: isolators are used on transmission and distribution lines, substations, and renewable installations, mounted on poles, towers, or equipment frames. Maintenance involves regular inspection for cracks, chips, or contamination, cleaning or washing to restore insulation performance, and timely replacement after damage or aging.

Standards and safety: insulators and isolating switches are governed by international standards from IEC and IEEE. Typical testing covers dry and wet withstand, puncture resistance, and aging simulations. Proper installation, operation, and maintenance are essential for system reliability and personnel safety.