Electric powerlines in electric Post hang very low in hot summer? Why?

Electric power lines in the electric posts hang very low during the summer to prevent overheating. They're often overloaded with high energy consumption and overheating could cause destruction of conductors. The high temperature could melt or expand the copper and aluminum materials. To protect public safety and guarantee an efficient energy transmission, the power lines are lowered to decrease temperature.

Answer: Power cables hang or sag during summer is because of thermal expansion.

Explanation: Materials tend to expand when exposed to hot temperature. An example of this are the copper wires in transmission lines. They expand when the temperature is high and tends to sag or hang.