What is the maximum pulling tension on a conductor that can be pulled in under tension as a percentage of the sag tension?

The maximum pulling tension on a conductor that can be pulled in under tension is determined by the concept of sag tension. Sag tension is the tension experienced by the conductor due to its weight and the distance between supports. It is essential to ensure that the tension applied during installation does not exceed a certain percentage of this sag tension to prevent damage to the conductor and maintain the integrity of the installation process.

The standard industry practice dictates that the maximum pulling tension should not exceed 70% of the sag tension. This limitation ensures that there is sufficient safety margin to accommodate dynamic loads, thermal expansion, and potential unforeseen factors that could affect the conductor's performance. By adhering to this percentage, linemen can minimize the risk of conductor failure or excessive stress that could lead to sagging or other integrity issues.

Understanding this percentage is crucial for lineman apprentices as it helps them make informed decisions during the installation of overhead conductors, ensuring their safety and the longevity of the electrical infrastructure.