Abstract:
The electrical switch (500) comprises a first and a second fixed contact (100, 200), and a movable knife contact (400) comprising at least one longitudinal pair of blades (410, 420) being flexibly connected to each other, whereby the blades form, in a switching event, contact with contact portions (120, 220) of the first and/or the second fixed contact. Opposite surfaces of the contact portions of the first and the second fixed contact comprise a roughened area (130, 230) and the inner surface of each blade comprises a protruded area (430) or opposite surfaces of the contact portions of the first and the second fixed contact comprise a protruded area (130, 230) and the inner surface of each blade comprises a roughened area.
Abstract:
A preventive maintenance tapping technique includes noting a tap position of a load tap changer and noting a duration that the tap position has been held. The duration that the tap position has been held is compared to a threshold value, and the tap position is changed if the tap position has been held for longer than the threshold value. Similarly, a duty cycle monitoring technique for monitoring life of load tap changer contacts includes detecting an arcing event. Arcing surfaces involved in the arcing event are identified and the effects of the arcing event on the arcing surfaces are calculated. Estimates of the erosion on the arcing surfaces are updated, and the estimates are compared to a threshold value. A signal for maintenance is generated when the estimate exceeds the threshold value.
Abstract:
A slide switch which can remove foreign particles, such as metallic dust, from its ground terminals. When a movable contact (4) moves toward its stroke end (S2) from a state where it connects the ground terminal (3) with (+B1) terminal (5), the contact section (4a) of the contact (4) first passes through the end section (5a) of the terminal (5) and leaves the terminal (5). At that instant, arcs are generated between the section (4a) and terminal (5). The metallic dust, carbide particles, etc., produced by the arcs scatter and fall onto an insulator (2) and, at the same time, on the (+B2) terminal (6) as well as the terminal (5). The metallic dust and carbide adhering to the sliding paths of the contact actions (4a and 4b) of the contact (4) are carried by the contact sections (4a and 4b) while sliding on the paths so that the dust drops into a discharge hole (8) and arc gap (G) through a notched hole section (7).
Abstract:
Procédé d'optimisation d'un courant de mouillage, pour un dispositif de supervision de capteurs à interrupteurs à contact comprenant une source de courant et au moins deux ensembles interrupteur / résistance (CT1/R1, CT2/R2) en parallèle, comprenant les étapes suivantes : • la source de courant (A) alimente le circuit avec un courant nominal; • si une tension mesurée (Vm) aux bornes desdits ensembles interrupteur / résistance est supérieure à une tension seuil (Vs), ladite tension seuil étant inférieure à la tension d'alimentation de la source de courant ainsi qu'à la tension de saturation du convertisseur analogique- numérique (CAN), alors la source de courant est arrêtée et des moyens de décharge du circuit sont mis en œuvre; • la source de courant réalimente le circuit avec un courant d'alimentation (lwet_c) égal au courant nominal diminué d'un pas prédéterminé. Ces deux dernières étapes sont réitérées jusqu'à ce que la tension mesurée soit inférieure à la tension seuil.
Abstract:
La présente invention concerne un commutateur électrique à contact frottant (3) comprenant d'une part au moins un contact fixe (9) et d'autre part au moins un contact frottant mobile (3) selon une trajectoire prédéfinie et présentant une surface de contact (10) destinée à frotter sur ledit au moins un contact fixe (9), caractérisé en ce qu'au moins ladite surface de contact (10) est traitée par bombardement ionique grâce à un faisceau d'ions, et en ce que les contacts fixe (9) et mobile (3) sont à nu.
Abstract:
An electrical contact (1) comprising a substrate (2) at least on one side provided with a noble metal contact layer (3). The contact layer (3) comprises a solid lubricant zone (4) close to an upper surface of the contact layer, with solid lubricant particles (5) embedded in the noble metal in the solid lubricant zone (4). A method of manufacturing such a contact comprising mechanically embedding solid lubricant particles into the contact layer (3), thereby forming a solid lubricant zone (4), or plating a solid lubricant zone (4).
Abstract:
The present invention comprises an electrical contact (84) having solid homogeneous conductive particles on the contact (84) surface. The particles are of greater hardness than that of the contact (84) material to deform the contact (84) material and cause breakage or fracture of the oxide or other contaminating layer, or to penetrate the contaminating layer. The particles are applied to the contact (84) surface by a technique which results in the particles being intimately bonded to the contact (84) surface, usually as a layer of particles. A preferable technique for such particle application is hypervelocity oxygen fuel spraying (HVOF) or plasma spraying, by which the particles are embedded on the contact (84) surfaces to provide a substantially permanent interparticle bond between the applied particles and the contact (84) material.
Abstract:
The present invention relates to an arrangement for purging at least one electrical contact in an elevator safety circuit, comprising at least one electrical contact (110) comprising a first contact point (112) and a second contact point (114) coupled to a control unit (120) in the first contact point (112) and to a load (130) in the second contact point (114), a capacitor (140) coupled between the second contact (114) of the electrical contact (110) and a third voltage, V3, and wherein the control unit (120) is configured to selectively introduce a first voltage, V1, and a second voltage, V2, to the electrical contact (110). The invention also relates to a method for implementing the purging.