230 kV O/H Line Steel Towers

[tolin]

Is there any American or Panamania standard, requirements or recommendations for steel towers used for high voltage circuits. I intent to connect a new 230 kV substation to an existing 230 kV overhead line at an existing suspension, tangent steel tower. Because of the cut and connection, we have to reconnect the two ends as dead ends, and have of cause started up calculation in order to examin the strenght of the tower. My problem is - is it allowed according to standards to use the existing suspension tower if the calculations say OK, or shall we make a new tower designed as a dead end tower.

 

[jghrist]

There is no restriction per se against having a deadend tap on a tangent tower, or to deadend the existing line at the tower. Of course, all strength and clearance requirements have to be met. Strength requirements in the US are defined in the National Electrical Safety Code (NESC) ANSI C2. The utility may also have more stringent requirements.

If you are deadending in both directions, the ruling span may be different on each side causing an unbalanced pull at conductor temperatures other than that at the time of construction.