When sagging a bundle of conductors, the tension in the bottom conductors should be approximately what percentage less than the top conductors?

In a sagging bundle of conductors, the top conductor experiences greater tension due to its position and the weight it is bearing from the entire bundle below it. As you move down the bundle, the tension in the conductors decreases because each successive conductor supports less weight, as they are not bearing the weight of the conductors above them.

The generally accepted practice in power line construction indicates that the tension in the bottom conductors should be approximately 3% less than that in the top conductors. This percentage accounts for the weight distribution and bending moments experienced in the bundle while ensuring that the structural integrity and electrical performance of the conductors are maintained. Additionally, a 3% lower tension helps to reduce potential sagging issues as the system is loaded or during thermal expansion and contraction.

Other percentage options, such as 1%, 5%, or 10%, do not reflect the standard industry practices for tension differences within a sagging bundle of conductors and could lead to inadequate performance or increased risk of failure if misapplied.