Abstract: The invention concerns a system for monitoring the operating condition of a switch by utilizing one or more integrating stages to determine the switching capacity and prevent overstresses. One or more monitoring devices for current, switch action rate, arc quench chamber insulation, contact condition, mechanical condition, operating temperature, or contact voltage are provided, which report the equipment condition, particularly the switching capacity. The sensors are functionally connected with the switchgear drive via a processing stage. The current sensors, together with a counting device, can report the .intg. i.n.dt, i.e. a measure of the stressing of the switch, and in doing so can disable the drive of the equipment. The invention serves the early detection of switchgear which is no longer fully operational, so that these can be replaced before an overstress occurs.

Abstract: Disclosed is a power drive for electric switchgear in which the driving force is elastically transmitted to an actuating member, for example, a handle. Thereby, tolerance compensation is provided to allow the drive motor to run into the end positions of the drive. A bending-type spring is disclosed as an elastic power transmitting member which is arranged transversely to the direction of motion of a slide which transmits the driving force to the switchgear. The bending-type spring can be connected to the slide. The bending-type spring can be a leaf spring, and more particularly two parallel leaf springs. In the disclosed embodiments, the two parallel leaf springs are provided as a single U-shaped leaf spring having parallel legs. The U-shaped leaf spring can either be supported at both ends thereof in the slide or the legs can be fastened in a mounting body connected to the slide.

Abstract: An arcing chamber for electric power circuit breakers is disclosed in which perforated, sieve-like ceramic plates define a wedge-shaped arcing space.An essential part of the disclosure is the use of conical holes in the plates which decrease in diameter from the arcing space sides of the plates toward the outside. The hole size used in areas where the arc travels and is quenched differs from that used in the remaining part of the arcing space. The space where the arc originates is made without holes.The invention is suitable particularly for fast-acting D.C. breakers.

Abstract: A low voltage circuit breaker having a housing of insulating material separated into an upper part and a lower part. A slot is provided one side wall of the lower part beginning at the parting line and extending to the lower edge of the lower part in which wires leading to an auxiliary device can be installed. An outlet is provided at the separation for these wires. The slot makes it possible to arrange several identical low voltage circuit breakers with connected auxiliary wires directly next to each other.