Technological constraints
HV switchgear (part 2)

In high-voltage circuit-breakers, with the exception of vacuum bulbs, it is necessary to distinguish between the functions of continuous current flow and arcing point (figure 7).

• Permanent (or main) current-carrying contacts are known as sliding contacts, because they ensure permanent contact between a fixed conductor and a moving conductor.

  For these contacts, which are permanently carrying the rated current (permanent contacts), we generally use copper parts electroplated with silver. Since silver oxide is a relatively good...