What is the maximum length of a sag section typically allowed?

The maximum length of a sag section that is typically allowed is 4 1/2 miles. A sag section refers to a portion of the power line where the conductor hangs lower than in adjacent spans due to the weight of the conductor and its sagging characteristics under gravity. The determination of the maximum length is based on engineering principles that ensure electrical reliability, mechanical stability, and safety standards are maintained in power distribution systems.

Allowing a sag section to extend to 4 1/2 miles strikes a balance between minimizing the number of structures required to support the line and ensuring that the sagging does not compromise the safety or functionality of the electrical system. Longer sag sections could lead to increased risks such as excessive swaying in high winds, potential clearance violations with trees or structures, and difficulties in maintaining the desired electrical transmission parameters.

By adhering to the maximum length of 4 1/2 miles, utilities can effectively manage these risks while providing consistent service to customers. This standard helps to maintain a safe distance from the ground, properties, and other infrastructure, facilitating safer and more reliable electrical distribution.