What causes damage to rubber due to high voltage?

High voltage can lead to the formation of a phenomenon called corona discharge, which can cause significant damage to rubber insulation materials. This occurs when the electric field around a conductor becomes strong enough to ionize the surrounding air, creating a conductive path for electricity. As the corona discharge occurs, it generates ozone, which is a byproduct of the ionization process. Ozone is known to be highly reactive and can degrade rubber over time, but the primary factor of interest here is the direct effect of the corona itself.

The intense electrical stress from the corona can lead to the breakdown of the rubber's molecular structure, resulting in premature aging, cracking, or overall degradation of the material. This type of damage is especially critical in lineman work, as the integrity of insulation is crucial for safety and effectiveness in electrical installations.

In contrast, while heat can affect rubber, it is not the primary cause of damage in high-voltage scenarios; instead, it may stem from electrical resistance or environmental exposure. Fracture relates to structural failure rather than the degradation process influenced by high voltage. Therefore, the emphasis on corona discharge is key in understanding how high-voltage systems can adversely affect rubber insulation.