Pre-operation Preparations
Personnel and Protection: Operators must wear insulating gloves and boots that have passed dielectric strength tests. For 110kV and higher voltage systems, the effective insulation length of the operating rod must be at least 1.2 meters. A dedicated supervisor must be present throughout the operation.
Equipment Inspection: Confirm that the series-connected circuit breaker is in the fully open position; check porcelain insulators for cracks (replacement is required if crack length exceeds 50mm); ensure transmission components are free from binding or deformation.
Environmental Check: Wind speed must not exceed Beaufort scale 8; ambient humidity must be ≤85%; remove ice if the accumulation thickness exceeds 2mm; ensure the operating area is free of standing water and debris.
Safety Verification: Use a qualified voltage detector rated for the specific voltage level to verify the absence of voltage on both sides of the equipment; confirm the proper functioning of the "five-prevention" interlocking system.
Standardized Operating Procedures
Closing Operation
Verify the switch identification number against the operation order; stand to the side of the operating mechanism, away from the potential arc path; remove the locking pin.
For single-pole disconnect switches, operate in the sequence of closing the outer phases first, followed by the middle phase. Advance the mechanism slowly and stop upon hearing the sound of the mechanical interlock engaging; avoid using excessive force at the end of the stroke.
After closing, confirm full contact of the contacts (contact resistance ≤200μΩ) and ensure the insertion depth meets specifications; lock the operating mechanism in place using the locking pin.