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OwnerCraig D. Bass, Richard D. Valenti, Jr. +1inventors
InventorsCraig D. Bass, Richard D. Valenti, Jr., Emer C. Flounders, Jr.
Estimating the term…
A system and method for testing underground electric cables, while in service, for active corrosion and degree of neutral loss. The method is conducted by applying a non-harmonic selected frequency signal to the neutral(s) of the underground cable connecting a pair of structures, e.g., power transformers, from a variable frequency generator of the system. The test is conducted by a surveyor wearing foot electrodes which contact the earth as the surveyor walks along the earth over the cable in a close interval steps. At each step, direct current (DC) potentials are monitored by a voltmeter between a copper-copper sulfate electrode carried by the surveyor and brought into contact with the ground at each step and the transformer ground. The potential of the gradients between the foot electrodes at the selective frequency and at the native alternating current (AC) is also measured by the voltmeter. These measurements are recorded at a stationary location on a digital data logger and/or computer. At all points of direct current or selective frequency potential abnormalities, a waveform is recorded of both potentials, as well as peak-to-peak potential measurements, maximum potential, minimum potential, mean potential, frequency, rms voltage, and soil resistivity to generate a continuous corrosion and condition profile of the entire length of cable including permanent land features.
A method for non-intrusively testing the status of corrosion of at least one neutral conductor of an underground electrical cable forming a portion of an electrical distribution system, said cable additionally comprising at least one primary conductor carrying AC current therethrough when said cable is in service providing normal electrical utility power to said distribution system, said neutral conductor of said cable being connected between a pair of electrically grounded structures, said method for testing being accomplished while leaving said cable in normal operation and comprising the steps of:
A non-intrusive testing system for determining the status of corrosion of at least one neutral conductor of an underground electrical cable forming a portion of an electrical distribution system, said cable additionally comprising at least one primary conductor carrying AC current therethrough when said cable is in service providing normal electrical utility power to said distribution system, said neutral conductor of said cable being connected between a pair of electrically grounded structures, said testing system being arranged for use with said cable while said cable is in normal operation and comprising:
Dependencies are inferred from the claim text.