The simple formula above applies to a conductor in still air at a standard temperature. In a real-world scenario, you must account for changes in temperature, as well as wind and ice loading.

1. Temperature Changes: As temperature increases, the conductor expands, which reduces tension and increases sag. As temperature decreases, the conductor contracts, increasing tension and reducing sag. The change in length (ΔL) is calculated using the coefficient of linear expansion (α):

   ΔL=α×(T2−T1)×L1

   This change in length directly impacts the tension and sag, and engineers use more complex equations (often solved graphically or with specialized software) to find the new sag-tension state.

2. Wind and Ice Loading: These factors add weight and force to the conductor, which must be included in the calculation.

   • Ice Loading (wi): Ice adds a vertical weight to the conductor.

   • Wind Loading (ww): Wind exerts a horizontal force.

   The total effective weight (wt) is a vector sum of the conductor's own weight (w) and the added loads.

   wt=(w+wi)2+ww2

   This effective weight is then used in the sag formula to find the slant sag of the conductor. The vertical sag can be calculated by:

   Svertical=Sslant×cos(θ) where θ is the blowout angle.