The sag and tension relationship must be carefully managed for two primary reasons:

1. Safety Clearances: Sag determines the minimum vertical distance of the conductor from the ground, roads, buildings, and other infrastructure. Too much sag can result in dangerous contact.

2. Structural Integrity: Tension determines the horizontal load on the towers and poles. Too much tension can overstress the conductor and supporting structures, leading to mechanical failure, especially under heavy wind or ice loads.

A successful power line installation achieves a balance, ensuring adequate sag for safety while keeping tension within safe limits for the conductor and supporting structures.