Installation and Commissioning Process and Handover Test Specifications for 10kV High-Voltage Switchgear

The installation quality and handover tests of high-voltage switchgear directly affect the safe operation of the power system. Strictly following specifications during installation and commissioning is the foundation for ensuring long-term reliable operation of the equipment. This article introduces the full-process operation requirements for installation and commissioning of 10kV high-voltage complete switchgear.

I. Pre-installation Preparation

Civil Condition Inspection

• The power distribution room floor is level, with embedded channel steel levelness deviation not exceeding ±1mm/m
• Cable trenches are completed, and cable supports are installed in place
• The power distribution room has moisture-proof and dust-proof conditions, with good ventilation
• Lighting and fire-fighting facilities are complete

Equipment Unpacking Inspection

• Check the packing list and verify that accessories and documents are complete
• Inspect the cabinet exterior for transportation damage or deformation
• Check insulating parts for cracks or damage
• Verify that nameplate parameters match the design drawings
• Check whether the circuit breaker truck moves in and out smoothly (for KYN28 type)

II. Cabinet Installation

Positioning and Arrangement

Determine the cabinet arrangement sequence according to the design drawings, starting from the middle to both sides or from one end. Adjacent cabinets are connected and tightened with bolts, ensuring the cabinet row is neat and verticality deviation does not exceed 1.5mm/m. The cabinets are welded or bolted to the embedded channel steel.

Main Busbar Installation

After threading the main busbars into the busbar compartment, check that the insulating bushings are intact. The busbar lap surfaces should be smooth and clean, coated with conductive paste, and bolts tightened with specified torque. Phase sequence markings should be clear and correct, and insulation distances between phases and to earth should meet requirements.

Earthing System

The bottom of each cabinet should be reliably earthed. The earthing busbar runs continuously along the cabinet row, with both ends securely connected to the main earthing grid of the power distribution room. Earthing resistance should not exceed 4Ω. The earthing jumper between the cabinet door and the cabinet body must not be omitted.

III. Handover Test Items

Insulation Resistance Test

Use a 2500V megohmmeter to measure insulation resistance of the main circuit between phases and to earth; for 10kV switchgear, it should not be less than 1000MΩ. For secondary circuits, use a 500V megohmmeter, with value not less than 1MΩ.

Power-frequency Withstand Voltage Test

Apply 42kV power-frequency voltage to the main circuit for 1 minute (48kV across open contacts) without breakdown or flashover. For secondary circuits, apply 2kV for 1 minute.

Circuit Resistance Test

Use a circuit resistance tester with at least 100A to measure the main circuit resistance of each circuit; the value should not exceed 120% of the factory test value. Pay special attention to circuit breaker contacts, disconnector contacts, and busbar connections.

Operation Test

• Perform manual and electrical opening and closing of the circuit breaker 5 times each; operation should be reliable without jamming
• Truck pushing-in and pulling-out operations should be flexible (for KYN28 type), with accurate positioning at working/test/isolated positions
• Opening and closing of the earthing switch should operate normally with appropriate operating force

Five-Prevention Function Verification

• The truck cannot be pushed or pulled when the circuit breaker is closed
• The earthing switch cannot be closed when the truck is in the working position
• The truck cannot be pushed into the working position when the earthing switch is closed
• The live compartment door cannot be opened (mechanical interlock)

IV. Protection Device Commissioning

The microcomputer-based integrated protection device shall be parameterized and functionally verified according to the setting schedule. Complete protection logic testing, trip tests, and signal verification to ensure comprehensive protection functions and correct operation.

V. Acceptance and Commissioning

Organize installation records, test reports, and drawing documents. Clean debris inside the cabinet and confirm no tools are left in any compartment. Close and lock all cabinet doors, and ensure indicating devices show correct status. Only after all conditions are met can power be applied. After commissioning, a 24-hour no-load trial run should be conducted with relevant data recorded.