My job is with the High Voltage maintenance department, and it really IS high voltage. Their main feeders carry 138,000 Volts! The cable terminations I'll be repairing carry a mere 34,500 volts. Our job is to maintain the substations, perform scheduled maintenance, and complete repairs in order to keep NASA's power needs uninterrupted.
This is a picture of two types of cable. The piece on the left is of Unishield 500 kcmil copper conductor with a solid dielectric (insulation) rated for 15kV. It's one of the most common types of cable that I've worked with. The cable on the right is the 138 kV power cable. The insulation is the part between the shiny copper conductor in the center, and the black jacket. Quite a difference in insulation thickness between the two.
