Maximum Conductor Tensions

Section 4 of AS/NZS7000:2016 includes this figure.

This diagram shows that a linear method of calculating conductor tension is valid up to about 50% of Conductor Breaking Load (CBL).

Poles ‘n’ Wires currently uses the linear method, which is appropriate for distribution lines.

If you want to tension a line greater than 50% (such as for sub-transmission lines) you need to use a non-linear method of calculating the tension. Poles ‘n’ Wires cannot perform these calculations.

An Option in Poles ‘n’ Wires is Options>Sag Tension>Tension Warning % (with a separate setting for bundled cables). This allows the user to set a value at which the program issues a warning when a cable is overloaded. However any percentage setting over 50 is ignored because of the maximum 50% CBL permitted for linear calculations.