Daily maintenance of high-voltage disconnectors

Routine maintenance of OCS disconnectors focuses on contact condition, operating mechanism and insulation:

• Check the contact blades and fixed contacts for burning, oxidation and pitting; clean and apply conductive grease.
• Measure contact resistance and compare with the initial value; investigate a rise above 20%.
• Inspect the operating mechanism for smooth travel, and lubricate the transmission parts.
• Verify the mechanical interlock and auxiliary contacts; confirm the remote indication matches the actual position.
• Check insulator surfaces for pollution, cracks and flashover traces; clean or replace as required.
• Confirm the grounding connection and the cabinet sealing are intact.

Recommended cycle: quarterly visual inspection, annual mechanical and electrical test, and immediate inspection after a short-circuit event.