Abstract: A gas-insulated switchgear includes a fixed-side electrode having a tubular fixed-side-conducting contact and a fixed-side shield for housing the fixed-side-conducting contact, and a movable-side electrode having a movable conductor driven by a driving unit to be connected to and separated from the fixed-side-conducting contact, facing each other in a container filled with an insulating gas. The switchgear includes a fixed-side-arc shield in the form of a circular plate, which is made of an arc-resistant member and has an opening of a diameter larger than the outer diameter of the movable conductor, the opening being formed on the side of the fixed-side shield facing the movable-side electrode. The fixed-side-arc shield is formed into a thin plate so as to cause an arc current to flow outward in a radial direction during contact parting of the fixed-side-conducting contact and the movable conductor to generate magnetic flux on a surface thereof in a circumferential direction.

Abstract: The present invention provides a wire lug arc vent barrier for protecting a wire lug in a molded case circuit breaker, with the circuit breaker having a housing with a terminal for a load connection and a terminal for a line connection. The wire lug/arc vent barrier comprises a body having a first end including a tang, a second end including an elongated finger and a middle portion between the first end and the second end defining a concave space, with an opening at each of the middle portion, wherein the body is mounted in the housing.

Abstract: A molded case circuit breaker or switch having the LOAD and/or LINE terminals thereof protected by a multifunctional terminal shield arrangement which also provides interphase barriers for the aforementioned terminals and associated wiring. The barrier also provides wire channels for lower voltage supplemental wiring.

Abstract: The gas circuit breaker comprises a metal container filled with an insulating gas; first and second contacts disposed opposite each other in the metal container so that they can be brought into and out of engagement with each other; and a metal shield arranged in the metal container to enclose the two contacts. A part or a whole of the surface of the shield is oxidized and covered with a fluororesin layer. The gas circuit breaker with this construction can protect the shield surface against flaking and scores when subjected to mechanical impacts and can maintain high dielectric strength without increasing the size of the circuit breaker.

Abstract: An insulation gas filled circuit breaker in which a circuit breaking portion including two separably opposing contacts and a capacitor connected in parallel between the two contacts in the circuit breaking portion are disposed in a closed metal container filled with gas having an insulating property. A shield is provided at both the side of the capacitor facing the circuit breaking portion and the side of the capacitor facing the closed metal container for relaxing the electric field concentration near the capacitor. The top end of the shield is positioned so as to extend from the contacting face between the capacitor and an electrode pressing the capacitor toward the capacitor by a predetermined distance, whereby the dielectric strength of the capacitor connected in parallel with the circuit breaking portion is increased and a highly reliable and compact insulation gas filled circuit breaker of a high voltage and a large capacity use is provided.