System of maintaining clean electrical contacts
AssigneeThe Raymond Corporation
InventorStephen L. Page
Life of this patent
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Abstract
A method is described for maintaining silver cadmium oxide alloy tips of an electrical contactor clean and substantially free of contamination involving operating the electrical contactor normally, under its regular working operation, in a cold switching mode, and at intervals of time, separating the tips under a load condition. A procedure is described also for determining at what interval the tips should be separated under the load condition. Apparatus is described that will operate to perform this method automatically.
Claims35
A method of maintaining the tips of an electrical contactor device in a clean and operable condition during use, comprising the steps:
- opening said tips during regular working periods in a cold switching mode;
- and
- at predetermined intervals of time, opening said tips while under a load condition;
- whereby an electric arc developed when opening said tips while under a load condition maintains said tips in a clean and operable condition substantially free of contamination.
A method of maintaining the tips of an electrical contactor device in a clean and operable condition during use at a preselected voltage, comprising the steps:
- opening said tips during regular working periods in a cold switching mode;
- monitoring said voltage during said regular working periods;
- and
- opening said tips, when said monitored voltage reaches a predetermined value, under a load condition;
- whereby an electric arc developed when opening said tips while under a load condition maintains said tips in a clean and operable condition substantially free of contamination.
A method of maintaining the tips of an electrical contactor device in a clean and operable condition during use at a preselected voltage, comprising the steps:
- opening said tips during regular working periods in a cold switching mode;
- monitoring said voltage during said regular working periods;
- and
- at predetermined intervals of time, derived from said monitoring step, opening said tips while under a load condition;
- whereby an electric arc developed when opening said tips while under a load condition maintains said tips in a clean and operable condition substantially free of contamination.
Apparatus for maintaining silver cadmium oxide alloy tips of an electrical contactor device in a clean and operable condition during use, comprising:
- means for opening said tips during regular working periods under a cold switching mode;
- and
- means for opening said tips at predetermined intervals of time under a load condition;
- whereby an electric arc developed when opening said tips under said load condition maintains said tips in a clean and operable condition substantially free of contamination.
Apparatus for maintaining tips of an electrical contactor device in a clean and operable condition during use, comprising:
- means for opening said tips during regular working periods under a cold switching mode;
- means connected with said tips to monitor a voltage developed across said tips during said regular working periods;
- microprocessor means connected to be responsive to said voltage for giving an indication when said voltage reaches a predetermined magnitude;
- and
- means responsive to said microprocessor means to initiate opening of said tips under load when said voltage reaches said predetermined magnitude;
- whereby an electric arc developed when opening said tips under said load maintains said tips in a clean and operable condition substantially free of contamination.
Dependencies are inferred from the claim text.