A vacuum interrupter having a structure to trap running cathode tracks is disclosed. The interrupter includes a first electrode assembly and a second electrode assembly, at least one of which is moveable. The interrupter also includes a sidewall having a longitudinal axis. One or more trench structures are formed in at least one of the electrode assemblies. Each trench structure has an opening that faces the other electrode assembly in a direction that is parallel to the longitudinal axis, to trap the running cathode tracks to prevent them from getting close to the sidewall.

A metal contact of a residential circuit breaker with ordered ceramic microparticles is provided. The metal contact comprises an electrical contact material comprising a metal alloy and ceramic particles to form a metal matrix composite material. Both materials the metal alloy and the ceramic particles are present together as a metal compound but without forming an alloy. The metal compound is a matrix and reinforcement being the ceramic particles such that first the ceramic particles has a sintering step to get a homogeneous preform for the metal compound being porous with a controlled size obtained by pressing a particle size of about few micrometers of the ceramic particles and then a liquid metal infiltration step to provide a homogenous distribution of the metal alloy and the ceramic particles in a three-dimensional open porous arrangement and the homogenous distribution results in ordered microstructures.

A contact assembly for an electrical device and a method for making such an assembly are presented. The contact assembly comprises a substrate and a contact material disposed on the substrate. The contact material comprises a composite material comprising a refractory material and a matrix material. The matrix material has a higher ductility than the refractory material. The composite material further comprises a core region and an outer region bounding the core region, the core region having a higher concentration of the refractory material than the outer region. The method applies cold spraying a blended feedstock to produce a layer that includes the composite material described above.

A contact assembly for an electrical device and a method for making such an assembly are presented. The contact assembly comprises a substrate and a contact material disposed on the substrate. The contact material comprises a composite material comprising a refractory material and a matrix material. The matrix material has a higher ductility than the refractory material. The composite material further comprises a core region and an outer region bounding the core region, the core region having a higher concentration of the refractory material than the outer region. The method applies cold spraying a blended feedstock to produce a layer that includes the composite material described above.

Fuse devices and electrical systems using the fuse devices are disclosed, with the fuse devices having internal components to cause a fuse blown event when the pre-determined current level is reached through the contacts. The internal components can comprise a levitation actuator that causes separation between one or more of the contacts as the current level approaches the predetermined level. This causes contact levitation and arcing, which increases the resistance at the contact being separated. This in turn causes the current through the contacts to seek another path that in the embodiments herein is a path to a pyro feature. The current activates the pyro feature, which causes the contacts to separate and puts the fuse device in “fuse blown” condition where currents can no longer flow through the contacts.

Provided is a method of manufacturing a contact material, including the steps of: forming a Ni alloy film having a film thickness of 40 nm or more and 110 nm or less on a surface of WC powder having an average particle diameter of 2 μm or more and 10 μm or less by an electroless Ni plating method; performing heat treatment for degassing at a temperature of 500° C. or more and 860° C. or less; crushing Ni alloy-coated WC powder after the heat treatment; mixing the crushed Ni alloy-coated WC powder and Cu powder having an average particle diameter of 1 μm or more and 100 μm or less; and compressing the resultant mixture, followed by sintering the mixture at a temperature of more than 1,083° C. and less than 1,455° C.

Provided is a method of manufacturing a contact material, including the steps of: forming a Ni alloy film having a film thickness of 40 nm or more and 110 nm or less on a surface of WC powder having an average particle diameter of 2 μm or more and 10 μm or less by an electroless Ni plating method; performing heat treatment for degassing at a temperature of 500° C. or more and 860° C. or less; crushing Ni alloy-coated WC powder after the heat treatment; mixing the crushed Ni alloy-coated WC powder and Cu powder having an average particle diameter of 1 μm or more and 100 μm or less; and compressing the resultant mixture, followed by sintering the mixture at a temperature of more than 1,083° C. and less than 1,455° C.

A vacuum interrupter having a structure to trap running cathode tracks is disclosed. The interrupter includes a first electrode assembly and a second electrode assembly, at least one of which is moveable. The interrupter also includes a sidewall having a longitudinal axis. One or more trench structures are formed in at least one of the electrode assemblies. Each trench structure has an opening that faces the other electrode assembly in a direction that is parallel to the longitudinal axis, to trap the running cathode tracks to prevent them from getting close to the sidewall.

A low voltage circuit breaker is provided. The low voltage circuit breaker includes a contact system with a first contact and a second contact that are electrically connectable and disconnectable relative to one another. The first contact includes a body having a first layer and a second layer, wherein the first layer is arranged on the second layer and is configured to come in contact with the second contact for providing the electrical connection with the second contact. The first layer has a first material composition having an Ag content that is higher than an Ag content of a second material composition of the second layer. Further, the first material composition has a WC content that is lower than a WC content of the second material composition.

A low voltage circuit breaker is provided. The low voltage circuit breaker includes a contact system with a first contact and a second contact that are electrically connectable and disconnectable relative to one another. The first contact includes a body having a first layer and a second layer, wherein the first layer is arranged on the second layer and is configured to come in contact with the second contact for providing the electrical connection with the second contact. The first layer has a first material composition having an Ag content that is higher than an Ag content of a second material composition of the second layer. Further, the first material composition has a WC content that is lower than a WC content of the second material composition.