Loop fault isolator
AssigneeDerek W. Moore
InventorDavid N. I. Ibbetson
Life of this patent
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Abstract
The invention comprises a method and a device for locating, isolating and by-passing a defective electrical device in an electrical circuit, and comprising sensing current and voltage at a first point in such circuit, on one side of such device, whereby the current and voltage are not significantly altered by the sensing process, sensing current and voltage at a second point in such circuit, on the other side of such device, whereby the current and voltage are not significantly altered by the sensing process, comparing such currents and voltages as between such two points, creating a control signal responsive to such compared currents and voltages, and, isolating such device from such circuit, and thereafter re-establishing such circuit whereby to by-pass such device, in response to a control signal of predetermined characteristics.
Claims15
A method for locating, and isolating and by-passing a defective electrical device in an electrical circuit, and comprising the steps of;
- sensing current and voltage at a first point in such circuit, on one side of such device, whereby the current and voltage at said first point are not significantly altered by the sensing process;
- sensing current and voltage at a second point in such circuit, on the other side of such device, whereby the current and voltage at said second point are not significantly altered by the sensing process;
- comparing such currents and voltages at said two points;
- creating a control signal responsive to such compared currents and voltages, and,
- isolating such device from such circuit, and thereafter re-establishing such circuit whereby to by-pass such device, in response to a control signal of predetermined characteristics.
An isolator unit device comprising a relay switch means, a current measuring means and a voltage measuring means for determining the acceptability of the current and voltage at a first point on one side of an electrical device, line or circuit, and a comparator means to compare the acceptability of current and voltage at the said first point with the acceptability of current and voltage at a second point on the other side of the said device, line or circuit, to determine whether a defect exists between the said points, to determine the location of a defect, if such is found to exist, between the said points, and to deliver a control signal to said relay switch means operable to isolate and by-pass the said device, line or circuit if a defect is found to exist between the said points.
An isolator station, for use in association with a series of electrical devices, lines or circuits, comprising:
- a plurality of isolator unit devices connected in series to each other, each isolator unit device comprising a relay switch means, a current measuring means and a voltage measuring means for determining the acceptability of the current and voltage at a first point on one side of one said electrical device, line or circuit, and a comparator means to compare the acceptability of current and voltage at the said first point with the acceptability of current and voltage at a second point on the other side of the said one device, line or circuit, to determine whether a defect exists between the said points, to determine the location of a defect, if such is found to exist, between the said points, and to deliver a control signal to said relay switch means operable to isolate and by-pass the said one device, line or circuit if a defect is found to exist between the said points, and,
- an interface unit connected to one of said isolator unit devices, which interface unit comprises a current measuring means and a voltage measuring means for determining the acceptability of the current and voltage at a point in an electrical device, line or circuit and includes an output means to deliver control signals to said one isolator unit device.
Dependencies are inferred from the claim text.