What are the long-term effects of repeated vegetation contact on the integrity of overhead conductors, beyond immediate outages?

While immediate outages are a primary concern with vegetation contact on overhead conductors, repeated contact causes several long-term effects that compromise conductor integrity. One significant effect is conductor abrasion. The rubbing of branches against the conductor surface wears away the outer layers, reducing the conductor's diameter and its ability to carry current. This abrasion can eventually lead to conductor failure. Another effect is insulation damage. Repeated contact can damage the conductor's insulation, reducing its dielectric strength and increasing the risk of flashovers. The damaged insulation is also more susceptible to moisture and contamination, further accelerating degradation. Corrosion is also accelerated by vegetation contact. The presence of moisture and organic acids from the vegetation can promote corrosion of the conductor material, particularly at the points of contact. This corrosion weakens the conductor and reduces its current-carrying capacity. Conductor annealing can also occur. Repeated arcing due to vegetation contact generates localized heating, which can anneal the conductor material, making it softer and weaker. Annealing reduces the conductor's tensile strength, making it more prone to sagging or breaking under mechanical stress. These long-term effects, beyond immediate outages, can significantly reduce the lifespan and reliability of overhead conductors, requiring more frequent maintenance and eventual replacement.