Tiered Maintenance Schedule
Routine Inspections (Daily/Weekly):Check the housing and porcelain insulators for cracks or flashover marks; verify that the open/close indicator matches the actual status; ensure the mechanism cabinet is sealed against moisture; check for abnormal noises or odors.
Monthly Maintenance: Clean accumulated dirt from equipment surfaces; check the tightness of wiring terminals; apply specialized high/low-temperature resistant grease to the operating mechanism's linkage joints; test the resistance of opening and closing coils (deviation from factory values ≤10%).
Quarterly Maintenance: Inspect energy-storage springs for deformation or corrosion; perform power-frequency withstand voltage tests on the vacuum interrupter contacts; tighten all mechanical linkage fasteners; remove moisture and dust from the mechanism cabinet.
Annual Comprehensive Overhaul: Conduct mechanical characteristic tests (opening/closing time, contact bounce time, three-phase synchronization); measure phase-to-phase and phase-to-ground insulation resistance using an insulation tester (≥1000 MΩ); re-verify contact gap and over-travel distances; replace aged seals.
Major Overhaul Cycle: Once every 5 years under normal operating conditions; first major overhaul one year after commissioning new equipment; mandatory maintenance following more than three fault-induced trips.
Specialized Maintenance for Core Components
Vacuum Interrupter (Critical Component)
Perform a 42 kV/1 min power-frequency withstand voltage test every two years; dielectric breakdown indicates vacuum failure, requiring the replacement of the entire interrupter unit-disassembly or repair by unauthorized personnel is strictly prohibited.
Mandatory replacement of the interrupter after 20 cumulative rated short-circuit breaking operations to prevent explosions caused by insufficient arc-extinguishing capability.
Conductive Circuit and Contacts
Scan wiring terminals and copper busbar connection points using an infrared thermometer; circuit resistance must be ≤40 μΩ (for 630A ratings); if resistance exceeds the limit by 20%, the contact surfaces must be polished.
Monitor contact wear; replace contacts promptly when wear approaches the manufacturer's specified limits to avoid compromising electrical conductivity and arc-extinguishing performance. Secondary Control Circuit
Tighten all secondary wiring terminals monthly and test auxiliary switch contact resistance (ensuring it is ≤50 mΩ) to guarantee reliable signal transmission for relay protection.
Inspect opening and closing coils for signs of overheating or discoloration; verify that the energy-storage motor operates with correct start/stop logic and exhibits no free-spinning or binding issues.