What does “line sag” refer to in overhead lines?

Line sag refers to the downward droop of overhead lines between poles due to the weight of the conductors and the tension applied to them. This sag is a crucial factor to consider in overhead line construction and maintenance because it can significantly impact both clearance above ground and the structural integrity of the line. If the sag is insufficient, the line may be too close to the ground or to other obstacles, potentially leading to safety hazards or code violations. Conversely, if sag is excessive, it can cause increased tension on the poles and hardware, which might lead to structural failures. Understanding line sag helps ensure that overhead lines remain safe, effective, and compliant with regulatory standards.