What a good rule of thumb to use for a maximum slack span?

[speedyse86]

I know that the maximum distance that an electrical line slack span can be used on depends on many things but just wondering if there is a general rule of thumb that would work for most conductors?

 

[PHovnanian]

A rule of thumb good for most conductors? Not likely.

First of all, you've got to define what you mean by 'slack' in terms of allowable unguyed side load on the structure. That number, together with the conductor weight and maximum tolerable sag for proper clearance will give you a span length. But as weight varies greatly between conductor sizes and types, there isn't likely going to be a 'one size fits all' number.

The best rule I use is to keep slack spans as short as possible. This can be accomplished by setting a pole in the lead as close as possible which will allow proper guying and sagging the rest of the line

 

[Electic]

Be aware that in addition to ground clearance, a slack span can wind whip phase to phase and will depend on crossarm length.