Abstract:
A transient voltage surge suppression device includes a varistor assembly having a compact thickness, and two different disconnect elements responsive to distinct overvoltage conditions to disconnect a varistor assembly prior catastrophic failure thereof. The varistor element (134) assembly comprises an insulating base plate (132) mounted stationary in the housing, the insulating plate having opposed first (160) and second sides (162); and a varistor element (134) having opposed first (150) and second sides (152), one of the opposing first and second sides of the varistor being surface mounted to one of the opposing sides of the plate (132) and the varistor element is operable in a high impedance mode and a low impedance mode in response to an applied voltage. Further, the varistor element is a metal oxide varistor and the insulating plate is a ceramic plate (alumina).
Abstract:
Electrical current sensing and monitoring methods include connecting sensing a voltage across a conductor having a non-linear resistance such as a fuse element. The current flowing in the conductor is calculated based on at least a first detected state of the sensed voltage and a thermal equilibrium characterization of the conductor.
Abstract:
A high voltage power fuse having a dramatically reduced size facilitated by silicated filler material, a formed fuse element geometry, arc barrier materials and single piece terminal fabrications. Methods of manufacture are also disclosed.
Abstract:
A power fuse includes a housing (202), first and second conductive terminals (204, 206) extending from the housing, and at least one fatigue resistant fuse element assembly (208) connected between the first and second terminals. The fuse element assembly includes at least a first conductive plate and a second conductive plate (302-310) respectively connecting the first and second conductive terminals, and a plurality of separately provided wire bonded weak spots (312) interconnecting the first conductive plate and the second conductive plate.
Abstract:
Fuse assemblies in the form of fuse blocks and fuse holders include embedded permanent magnet arc suppression features that facilitated higher voltage operation of fusible circuit protection without increasing the size of the fuse assemblies. The embedded magnets apply an extemal magnetic field upon an overcurrent protection fuse and produce an arc deflection force to enhance arc quenching capability of the fuse without increasing its form factor.
Abstract:
Systems and methods for detecting thermal-mechanical strain fatigue in an electrical fuse (100,200,352) include a controller (362) configured to monitor (722) at least one fuse fatigue parameter over a period of time while the fuse (100,200,352) is connected to an energized electrical power system, and based on the monitored at least one fuse fatigue parameter, the controller (722) is further configured to determine (726, 728) at least one of a consumed service life of the fuse element or a service life remaining of the fuse element.
Abstract:
Electrical current sensing and monitoring methods include connecting a compensation circuit across a conductor having a non-linear resistance such as a fuse element. The compensation circuit injects a current or voltage to the conductor that allows the resistance of the conductor to be determined. The current flowing in the conductor can be calculated based on a sensed voltage across the conductor once the resistance of the conductor has been determined.
Abstract:
A compact fusible disconnect switch device includes a magnetic arc deflection assembly including at least a pair of magnets disposed about a switch contact assembly. The magnetic arc deflection assembly facilitates reliable connection and disconnection of DC voltage circuitry well above 125 VDC with reduced arcing intensity and duration. Multiple pairs of magnets may apply magnetic fields in directions opposing one another to deflect magnetic arcs in different directions at more than one location in the switch contact assembly to facilitate high voltage DC operation.
Abstract:
A transient voltage surge suppression device includes a varistor assembly having a compact thickness, and thermal disconnect assembly carrying a separable contact bridge movable along a linear axis to disconnect the varistor element from external circuitry.
Abstract:
Fuse assemblies in the form of fuse blocks and fuse holders include embedded permanent magnet arc suppression features that facilitate higher voltage operation of fusible circuit protection without increasing the size of the fuse assemblies. The embedded magnets apply an external magnetic field upon an overcurrent protection fuse and produce an arc deflection force to enhance arc quenching capability of the fuse without increasing its form factor.