Abstract: A phase breakdown- and null current detector, especially in or for an electronic motor protection relay with current-dependent response or triggering, which is controlled by detection alternating-current voltages proportional to current values in the motor outer conductors and contains an electrical motor simulator representative of the thermal or heating behavior of the motor due to the charging operation of a capacitive storage. The motor simulator can be adjusted by a controlled switching device to different time-constants corresponding to the operating conditions of the motor.

Abstract: A gas-blast switch possessing a fixed contact and a movable contact and a blast or discharge nozzle surrounding one of the contacts, the blast nozzle having its inlet connected with the outlet of a pump compartment for an extinguishing gas, this pump compartment can be pressurized by the switch cut-off or switching-off movement, and wherein the narrowest location or throat of the blast nozzle is arranged in the direction of blowing downstream with respect to the aforementioned one contact. The outlet of the pump compartment can be closed by a check or nonreturn valve which closes in the direction of the pump compartment. The inlet of the blast nozzle is connected via a gas chamber with the outlet of the pump compartment, the outlet of the gas chamber confronting the blast nozzle can be closed by means of a further check or nonreturn valve which closes in the direction of the gas chamber.

Abstract: A high-speed grounding apparatus for metal encapsulated high-voltage switching installations embodying a grounding bolt which, by igniting a propellent charge, can be forwardly shifted out of its rest position into its grounding or earthing position for electrically connecting the capsule with a conductor encapsulated therein. An ignition device is provided for the propellent charge, this ignition device being triggered by an increase in pressure in the switching installation.

Abstract: A gas blast circuit breaker has fixed and movable contact sets, the latter mounted on a cylinder slidable on a fixed piston to generate a gas blast on separation of the contact sets. Each contact set consists of radially inner and outer contacts, the inner contacts separating later than the outer. A gas blast nozzle mounted on the cylinder and between the radially inner and outer movable contacts has a throat downstream of the inner contact, communicating with the interior of the cylinder by way of an inner duct containing the inner contact, and an annular outer duct, so arranged that on separation of the contacts relatively cool fresh quenching gas is directed through the inner duct over the inner contact and arc.

Abstract: A gas-blast insulated, encapsulated high-voltage switching installation with removable bus bars wherein the switching installation contains components consisting of housings with flanged connections and internal elements secured therein as partitions by means of conical support insulators and forming pressure gas tight compartments and wherein the bus bars contain disconnectors as well as dilatation elements. At each housing of the bus bar component there are provided two oppositely situated connection flanges and in each housing there is arranged an internal conductor element.