In the summer, because of thermal expansions, the electric wires sag, and in the winter, due to contraction, they may break. As a result, when setting up the wires between the poles, it’s important to keep them somewhat loose in the summer so that they don’t break in the winter due to contraction.
For more such videos : https://www.youtube.com/c/ExperiHub?sub_confirmation=1
For more Science related blogs and videos : https://experihub.com/did-you-know/