摘要:
To check the presence of operating vacuum in vacuum switches, high voltage can be applied between the contacts at a given contact spacing and the dielectric strength can be tested. According to the invention, the procedure for vacuum monitoring is that a contact spacing (h) below the nominal stroke of the vacuum switch is selected and that the X-radiation generated at this contact spacing (h) and high voltage (U) in vacuum due to the field electron emission between the contacts by the contact surfaces acting as anode is acquired and evaluated as proof of the presence of operating vacuum inside the switching tube. This method can preferably be applied to encapsulated vacuum switching tubes, in particular to SF.sub.6 -insulated switching facilities. Associated with the vacuum switching tube (15) in the associated equipment is an X-ray detector, preferably a Geiger-Muller counter, which is connected to the high-voltage unit (25) via an evaluating circuit (30 to 50) which serves for the determination and indication of the operating vacuum and shuts off the high-voltage unit (25) to minimize the X-ray dose. Due to the X-ray emission, which is stopped long before reaching impermissible values, the presence of vacuum can be positively verified.
摘要:
Contact pieces for vacuum switches with axial magnetic field are designed e.g. as cup contacts with slotting in the same direction which support a diskshaped contact body and have means for the suppression of eddy currents. According to the invention, the contact bodies (10, 20, 30, 40, 50) have, at least on their backside, radial areas (15, 25, 35, 45, 55) of markedly lower electrical conductivity than the base material. Such radial areas may be, grooves (15 to 18) on the backside (12) of the contact body (10), diffusion zones (25, 35) of additives reducing the electrical conductivity of the base material, or combinations of the two. If the contact bodies (40,50) are made by powder metallurgical methods, it is also possible to provide the radial areas during production as fillings (45) or as molded parts (55) of a material of lower electrical conductivity than that of the base material.
摘要:
Contact pieces for vacuum switches with axial magnetic field are designed, for example, as pot type contacts with codirectional slotting which contain in each instance a disk-shaped contact body of contact material and have an arrangement for the suppression of eddy currents. Conventional techniques for this purpose typically involves the cutting of radial slots in the contact bodies. In accordance with the invention, each contact piece (10, 110, 210) comprises a plurality of discrete elements (11, 111, 211) which are so arranged on the concrete carrier (2) that their edges (12, 13; 112, 113; 212, 213) form joints (25, 125, 225) and thereby define conductivity jumps for the suppression of the eddy currents. Specifically the discrete segments (111, 211) are produced by reshaping a cylindrical blank (100) of circular cross section into a semi-finished product of circular sectorial cross section.
摘要:
In a contact arrangement for air-blast switches, a tubular element consisting of ferromagnetic material (the inner wall surface of which is conical and continues the contour of a nozzle aperture) is provided with a layer of graphite. The layer is formed by one or more bushings which are force fitted into the tubular element. The desired conical inner contour can be produced by machining initially cylindrical inner surfaces after mounting the bushings within the tubular element.
摘要:
A method for manufacturing melt materials of copper, chromium, and at least one readily evaporable component as well as a fusible electrode for using this method is disclosed.More specifically, an arc melting method is used for the manufacture of melt materials based on copper and chromium in which the electrode material melting off a fusible electrode of given resultant composition is collected in a water-cooled permanent mold for the purpose of cooling down without macroscopic separation of copper and chromium.A fusible electrode for use in this method is also provided. This fusible electrode partially consists of a solid alloy of copper with the readily evaporable component.
摘要:
An electric gas blast circuit breaker is disclosed which has two stationary contact pieces. A switching unit is movable between closed and open positions for electrically bridging the contact pieces in the closed position and for electrically disconnecting the contact pieces in the open position whereby an arc develops when the switching unit is moved to the open position. A gas blast device blasts a stream of gas through the arc when the switching unit is moved to the open position. The switching unit includes a supporting body and a slide-contact ring made of an arc-resistant material. The ring slideably contacts one of the contact pieces in the closed position and is mounted on the supporting body so as to be electrically insulated therefrom. A plurality of elongated contact elements are disposed in the supporting body for electrically connecting the contact pieces when the switching unit is in the closed position. There is provided an electrical connection between at least one of the contact elements and the slide-contact ring when the switching unit is in the closed position and also when it moves into the open position and continuously in all operating positions thereof.