In electrical engineering, live-line working is the maintenance of electrical equipment, often operating at high voltage, while the equipment is energised.
A lineman wearing a Faraday suit can work on live, high-power lines by being transported to the lines in a helicopter. Wearing the suit, they can crawl down the wires.
Jovett:The two wires are the same voltage, and essentially the same conductor. Using more than one actual wire has great benefits, the largest of which is carrying more electricity with less weight. This is because electricity tends to travel on the surface of a conductor versus through its center. With two wires, you double the surface. Many meters separate the wires (called pairs or bundles) for the different phases, so there is no risk of accidentally touching another one.