Pre-operation Preparations
Wear full high-voltage insulating protective gear; verify that the operator holds a valid high-voltage electrician's certificate; and implement a two-person supervision protocol.
Verify that the current switchgear unit number matches the target unit specified in the operation order; confirm that the current status of the withdrawable unit and the grounding switch meets the prerequisites for operation.
Prepare the dedicated operating crank and transfer trolley; ensure beforehand that the trolley tracks are perfectly aligned with the switchgear guide rails and securely locked in place.
Ensure the withdrawable unit compartment door is open at an angle of ≥90° to prevent the door from striking the unit's components during operation.
Full Procedure for Energization and Insertion
Positioning and Docking: Push the dedicated transfer trolley to the front of the switchgear; align it with the positioning holes and engage the locking hooks; adjust the trolley height to ensure a seamless connection between the trolley tracks and the switchgear guide rails.
Insertion to Test Position: Confirm the circuit breaker is open (tripped); steadily push the unit into the "Test" position within the cabinet; lock the connection mechanism between the unit and the cabinet; disengage the trolley lock and remove the trolley.
Secondary Circuit Verification: Insert the secondary plug and lock it securely; close and lock all cabinet doors; ensure control and energy-storage power switches are closed (ON); and verify that voltage readings are normal.
Operational Testing: Perform one closing and one opening operation of the circuit breaker (either locally or remotely) while in the "Test" position; verify that the switching actions are normal and signal feedback is correct.
Racking to Service Position: Insert the operating crank and rotate it clockwise; stop upon hearing the "click" of the locking mechanism; ensure the unit has fully entered the "Service" position and the main circuit contacts are securely engaged; remove the crank.
Final Status Check: Observe that all three-phase indicator lights on the live-line display are lit; verify that voltage and current parameters on the microprocessor protection device are normal; and confirm the "Service Position" indicator light is illuminated.