Contact system for gas blast circuit breaker - has nozzle shaped slotted contacts filled with arc-resistant insulant

摘要

The circuit breaker has two coaxial, hollow slotted contacts with U-shaped cross section. They are in electric contact with each other in the ON position, and form in the OFF position a gap between their slotted butt-ends. Each contact forms a nozzle element and is filled in the slot area with an arc-resistant insulating material (10). This insulating material has such admixture of a conducting material that its conductivity is lower than that of the contact material. Preferably the insulant is a cast resin and the conductive admixture is graphite. The contact elements may be also of graphite.