| US 7,482,714 B2 | ||
| Preventive maintenance tapping and duty cycle monitor for voltage regulator | ||
| Fred J. Rapant, South Milwaukee, Wis. (US); Richard J. Kaluzny, Greenfield, Wis. (US); Donald A. Down, Brookfield, Wis. (US); and Augusto D. Hernandez, Brookfield, Wis. (US); Augusto D. Hernandez, Jr., legal representative | ||
| Assigned to Cooper Technologies Company, Houston, Tex. (US) | ||
| Filed on May 31, 2005, as Appl. No. 11/139,969. | ||
| Application 11/139969 is a continuation of application No. 10/927505, filed on Aug. 27, 2004, abandoned. | ||
| Claims priority of provisional application 60/500687, filed on Sep. 08, 2003. | ||
| Prior Publication US 2006/0028235 A1, Feb. 09, 2006 | ||
| Int. Cl. H01H 1/60 (2006.01); H01H 9/30 (2006.01); H01H 7/00 (2006.01); H01H 19/00 (2006.01) | ||
| U.S. Cl. 307—137 [307/141; 200/11 TC; 200/19.04; 200/19.07] | 46 Claims |
| 1. A method for automatically cleaning contacts of a load tap changer, the method comprising:
noting a first tap position in which first tap contacts are engaged by movable contacts;
noting a duration of inactivity during which the first tap position has been held;
comparing the duration that the tap position has been held to a threshold value; and
moving from the first tap position to a second tap position by moving the movable contacts to engage second tap contacts that
are distinct from the first tap contacts if the first tap position has been held for longer than the threshold value to thereby
wipe the contacts.
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