Sag Of Line Wires

Just look for it. There's a ton of instant answers on the web.

I could have given you my opinion, but why would you take my word for it? I expect that wire suppliers may have this information on their web sites, too. I'm not an electrician, I'm just an opinionated old man.

Sag and Tension of Conductor

First off, the term is cantenary. Sag is what you get when you get old.

Sorry, the term is catenary.

A true catenary curve would not account for the sag in an energized, suspended electrical conductor.

"Sag is what you get when you get old."

damn, beat me to it. My line was going to be that sag can be calculated based on the span of years over 40 and corrected by surgical implants.

http://www.eng.uwi.tt/depts/elec/staff/alvin/ee35t/notes/Transmission-Line-Construction.html

The sag is the center of a parabola (in an horizontal connection), calculated to have the same tensile strength on both ends. This parabola is mainly due to the weight of conductor, plus another things, such as the weight of possible insulators, vertical connections, weight of accidents such freeze, snow, even rain or dust (anything which could be hung up to the cable, including birds and leaves.This is easy for an horizontal connection; More complicate if it's not horizontal because, in that case, one side of the parabola is heavier than the other, and this complicate the calculation of the tensile strength of the higher end of connection. So much complicate when it snows often, because, in that case, the connection becomes unbalanced. It should be possible to calculate the connection in leaning the parabola (it's just a trick) up to the downward end, in order to calculate quickly. It 's just good for small copper connection (outer diameter less than 1 centimeter). Over, and for alu/steel connection, you have to execute a transformation of Fourier, in making an assembly of every slices of the surface described by the connection. Each vector of force is in line with the tangent of that parabola. Each slice has to be as thin as possible to be near the truth. That calculation may be made graphically, but not evident to find each particular vector of forces (each piece of load is vectorised and rotate around the center of that connection, from one end to the other). Each software i know about sag calculation is almost correct but not complete. There is always a lack of something (calculation of freezing thickness, for example). Each software doesn't take in account the derivating vector of wind, for instance. The connection is like a sail in the wind, and, if the wind changes, the soft doesn't take it in account. if you may some storm in your country, it could be a real nuisance (In that case, calculate the effect of the wind in the four directions, and make a vectorised sum to find the resultant).

Good luck, brzk.