Patent ID: 6957117
Filing Date: 2005-10-18
Classification: G01R,H02G

Abstract:
1. A method for designing and validating, including testing, a portable protective air gap (PPAG) device including a first and second electrode, suitable for use at a worksite of a particular utility company, the worksite including at least two tower support structures, each at electrical ground potential, for supporting a multiphase, electrical voltage transmission line network used to transmit a known, power frequency system, multiphase voltage of known nominal system voltage, phase to phase, kV rms, ph-ph , the transmission line network including a respective electrical transmission line for at least each phase of the multiphase voltage, each of said transmission lines suspended from a respective segment of the tower support structures by insulating electrodes, the tower support structures having a unique shape based in part on the magnitude of the power frequency system voltage transmitted on the lines of the transmission line network, the PPAG device to be suitable in design to protect a worker positioned at the worksite on or about the tower support structures, and engaged in live-line maintenance, against the possibility of voltage sparkover across one or more of a plurality of air gaps between the worker and each respective electrical transmission line, the method comprising the steps of: (a) establishing a set of performance criteria to consider in the design and testing effort including one or more of at least the following, (b) identifying a set of important parameters that affect the sparkover voltage for a specific air gap of the PPAG design, including, (c) performing a series of determinations and calculations, including, (d) determining the shortest phase to structure distances for the tower support structure supporting the line voltages in which the PPAG is to be deployed; (e) building a prototype PPAG, PPAG (f) installing the PPAG (g) powering said at least one phase of the multiphase, electrical voltage transmission line network of known nominal system voltage, with said known nominal system voltage; (h) testing the PPAG (i) ascertaining the actual breakdown voltage of the PPAG (j) adjusting the gap distance, D