General Electric Company

Thomas & Betts International LLC

Kht Fuses, L.l.c.

John G Leach

Robert E Koch

James J Carroll

Gerhard Frind

Gerald J Carlson

Radhakrishnan Ranjan

John H Van Noy

William E Lazenby

Ronald E Bennett

Ronald E Bennet

Radha K Ranjan

A fuse including a fuse housing having first and second electrical terminals, a movable partition made from an electrically conductive material movably disposed within the fuse housing, a fusible structure connected between the first electrical terminal and the movable partition, a conductor connected between the movable partition and the second electrical terminal, a biasing element acting on the movable partition to maintain the fusible structure in tension and for moving the movable partition upon melting of the fusible structure and an indicator connected between the movable partition and the second electrical terminal. The conductor, the movable partition and the fusible structure define an electrical path between the first and second electrical terminals and the indicator protrudes out of the second electrical terminal of the fuse housing upon melting of the fusible structure for providing visual indication of an interrupted condition of the fuse when subjected to a threshold current flowing therethrough.

Fuse providing circuit isolation and visual interruption indication

An improved high voltage, full range, current limiting fuse with enhanced ability to dear high and low fault currents, even after the fuse has been subjected to a potentially damaging current surge, includes a sand-filled tubular housing with conductive terminals at either end and a dielectric support member supported therein about which a fusible structure is spirally wound. The fusible structure is electrically connected to the terminals and includes one or more high fault current interrupting elements for clearing high fault currents to which is mounted a low fault current interrupting assembly. The low fault current interrupting assembly includes a plurality of conductive components one of which is a damage sensor portion having a melting time-current characteristic which results in the damage sensor portion melting before the one or more high fault current interrupting elements. This enables the fuse to interrupt a low current which might exist after an element-damaging surge has occurred. A thermal shield mounted to the housing adjacent the low fault current interrupting assembly prevents damage to the housing caused by arcing in the low fault current interrupting assembly.

Full range current limiting fuse to clear high and low fault currents

An apparatus for triggering chemical augmented electrical fuses includes a light source which emits a light signal in the form of visible or infrared light energy upon receiving a signal from a control system, trigger signal source or other fuses. The light signal is coupled to a light detector by an optical coupling device such as a fiber optic cable. Upon receipt of the light signal, the light detector generates a signal which causes the application of electrical energy to exothermic material in a fuse, thereby detonating the material and causing interruption of current through the triggered fuse.

Apparatus for triggering chemically augmented electrical fuses

An exothermically assisted electric fuse, having at least one exothermic body disposed in heat transfer relationship with at least a portion of each fusible element of the fuse, a triggering circuit for initiating an exothermic reaction in response to an overcurrent through the fuse, and a containment body partially enclosing the exothermic body for directing the heat energy released by the exothermic reaction. The containment body is disposed so as to confine and direct the heat energy in a direction which is substantially perpendicular to a plane containing the portion of the fusible element which is in heat transfer relationship with the exothermic body. In a preferred embodiment of such a fuse, the fusible element is wound around a support so that the fuse windings form the general shape of a cylinder, and the containment body is disposed so that the heat energy is directed in a radial direction with respect to the cylinder formed by the fuse windings. The exothermic body preferably comprises a two-part structure in which a mixture of boron and potassium perchlorate acts as a primer for a larger body of exothermic material formed from a mixture of aluminum and potassium perchlorate.

Exothermically assisted electric fuse

This high voltage fuse comprises a pair of spaced terminals and a fusible conductive element connected between the terminals. At spaced locations along the length of the fusible element, there are bodies of a material that exothermically reacts when heated to a predetermined temperature. Connected between the terminals independently of the fusible element is a triggering circuit. The bodies of exothermic material are connected in good heat-transfer relationship with the triggering circuit and the fusible element so that the heating effect of current through the triggering circuit upon disruption of the fusible element causes the material of said bodies to exothermically react and thus cause further disruption of the fusible element at additional locations respectively located adjacent said bodies.

High voltage electric fuse

A high voltage fuse with an element operating at relatively high temperatures and having such element comprised of a metallic material which is highly susceptible to oxidation at such temperatures is disclosed. The fuse element has predetermined dimensions so as to have a predetermined time-current characteristic. The high voltage fuse has a sealed environment for housing the fuse element. The fuse element has a thickness dimension sufficiently great so that any oxide layer that may accumulate on the fuse element over a service period of 15 years does not significantly affect the predetermined time-current characteristic of the fuse element during the period.

High voltage current limiting fuse having a fuse element susceptible to

A high voltage fuse for interrupting a wide range of currents and especially suited for low current interruption is disclosed. The fuse is comprised of a fuse element having a first and a second plurality of portions of reduced cross-sections. The second plurality of portions further comprise two or more parallel conducting paths some of which carry a portion of material which has a lower melting temperature than the melting temperature of the material of the fuse element. The parameters of the first and second plurality of reduced cross-section portions, the lower melting point material, and the fuse element itself are selected to adapt the fuse to provide proper protection for the various current conditions to which a high voltage transformer is subjected. The fuse element provides fast rupturing under short-circuit current conditions while also providing the characteristic of withstanding relatively high inrush current conditions. The fuse element further provides improved low current clearing ability for the fuse, and a fuse which responds quickly to through fault (secondary fault) conditions in a transformer.

High voltage fuse for interrupting a wide range of currents and

A high voltage fuse having mounted gas evolving members and method of forming such a fuse are disclosed. The high voltage fuse comprises, in part, a plurality of block shaped gas evolving members attached to a plurality of fuse elements, which, in turn, are wound about a supporting core. The high voltage fuse also has an electrically insulating casing in which is mounted the core having the wound fuse elements and the attached blocks of gas evolving members. The fuse casing is filled with a pulverulent arc quenching filler material. The block shaped gas evolving members have a narrow slit which allows the gas evolving members to be easily slipped over the fuse element so as to cover part or all of a transverse portion of the fuse. The gas evolving members are positioned over the fuse element at locations along the core so that the block type gas evolving members are arranged between adjacent portions of the ribs of the core. The block type gas evolving members are further positioned in desired locations by disposing the gas evolving members between the adjacent turns of the fusible elements. Positioning the gas evolving material blocks at their desired locations provides stationary boundaries and limits the movement of the gas evolving material during the filling of the fuse casing by the pulverulent arc quenching filler material.

High voltage fuse having mounted gas evolving members and method of

A high voltage fuse comprised of a fuse element wrapped about a core, enclosed in a housing member, and surrounded by a granular quartz material is disclosed. The core has a plurality of cutouts along its outer surfaces having preselected dimensions relative to the width of a fuse element of such values as to assure that at least one cutout is interposed between adjacent turns of the fuse element. The interposed cutouts increase the creepage between the adjacent turns of the fuse element. The preselected dimensions of the cutouts relative to fuse-element width provide a single core that is capable of accommodating numerous types and different numbers of fuse elements. The core is also provided with a gas evolving material attached to the cutouts and separated from the fuse element by a predetermined amount to provide controlled release of arc-quenching gas, when arcing inside the fuse occurs.

Growing community of inventors

Hickory, NC, United States of America

John G Leach