izolátor

An isolator, often referred to as an insulator in electrical engineering, is a material or device that resists the flow of electric current and provides electrical separation between conductors or between a conductor and the ground. Insulators are essential for the safe operation of power systems, enabling support and isolation of energized components while preventing unwanted leakage of current.

Materials used include porcelain, glass, and synthetic polymers. Porcelain and glass insulators have high dielectric strength and mechanical rigidity but can be heavy and brittle. Polymer insulators, made from composite materials with a silicone rubber housing, offer light weight and hydrophobic surfaces that shed water, reducing leakage current under wet conditions.

Forms of insulators used on power lines include pin insulators, suspension insulators, and strain insulators. They are designed to withstand high voltages, with creepage distances and puncture voltages specified for different service conditions. Insulators must resist environmental aging from pollution, moisture, temperature cycles, and UV exposure.

Applications include transmission lines, distribution networks, and substation equipment, where insulators support conductors and insulate them from support structures. In high-voltage systems, insulating performance is evaluated through tests of dielectric strength, leakage current, and aging.

In electrical practice, the term isolator is also used for a disconnector device, a switch intended to create a visible open circuit for maintenance. Such devices are designed to operate under no-load or with limited current and are installed with other protective equipment to ensure safety.