Maintenance and Repair Items for 10kV High-Voltage Switchgear

I. Routine Maintenance and Inspection

(1) Visual Inspection of Switchgear Enclosure

• No deformation or physical damage to the enclosure.

• Protective paint coating shows no severe rust, peeling, or flaking.

• Cabinet is securely installed, clean on the surface, and free of foreign objects.

• Nameplates and identification labels are neatly affixed and not falling off.

(2) Check of Switchgear Operating Parameters

• Instruments and meters indicate normal values (comparable to typical operating data, with no significant deviation and consistent with equipment status).

(3) Temperature Check of Components, Electrical Connections, Wires, and Cables

• Use an infrared thermometer to measure accessible components, electrical joints, wires, and cables: operating temperature ≤ 60°C.

• No unusual odor inside the cabinet.

(4) Check of Switch Positions, Indicator Lights, Meter Displays, and Selector Switch Positions

• Circuit breaker open/closed position correct.

• No alarm indications.

• All selector switches are in the correct position.

II. Annual Scheduled Maintenance

(1) Enclosure Inspection, Cleaning, and Defect Correction

• Wipe with alcohol and clean cotton cloth to ensure no dust accumulation or stains.

• Inspect protective paint for severe rust or peeling; if found, perform rust removal and repaint.

(2) Cable Compartment Inspection and Maintenance

• Cable entry seals are intact.

• Cable plug fixing screws are not loose.

• Cable identification tags and phase color markings are present and not missing or detached.

• Cable compartment is dry, with no condensation; clean and dust-free.

• Wipe insulators with alcohol and clean cotton cloth to ensure no dust or contamination.

• Grounding conductor is secure with no looseness.

(3) Grounding Switch Inspection

• Manually operate the grounding switch through one full open-close cycle.

• Operation should be smooth, without jamming.

• Switch position must match the indicator on the front panel.

(4) Circuit Breaker Compartment Inspection and Maintenance

• Withdraw the main circuit breaker to the test position and use a trolley to pull it outside the compartment. Inspect the primary isolation contacts and connected copper busbars for signs of burning or arcing. If necessary, polish with sandpaper and clean with alcohol-soaked cloth.

• Apply a uniform layer of conductive grease (0.5–1 mm thick) to the main circuit breaker’s isolation contacts.

• Tighten all primary circuit bolts to specified torque values. After tightening, check that spring washers are flat. Mark anti-loosening lines on all tightened bolts.

• Wipe all components inside the circuit breaker compartment with alcohol and clean cotton cloth to ensure no dust or contamination.

• Reinsert the circuit breaker trolley into the compartment and move to the test position. Perform one manual close-open operation cycle. Verify smooth operation, correct mechanical position indication, breaker position indication, and spring charged/uncharged status.

• After verification, move the breaker to the service position and perform power on/off operations as required.

(5) Secondary Circuit Compartment Inspection and Maintenance

• Check secondary wiring: connections must be tight and wire labels clear.

• Ensure compartment is clean: no dust or foreign objects.

• If necessary, clean and re-tighten secondary terminals.

III. Annual Electrical Testing

(1) Main Circuit Insulation Resistance Test

• Use a 2500 V megohmmeter.

• Measured value > 50 MΩ.

(2) Power Frequency Withstand Voltage Test
(Test on main circuit: phase-to-ground, phase-to-phase, and across open contacts)

• After major maintenance: apply test voltage as per standard.

• During service: apply 80% of the standard test voltage.

(3) Insulation Test of Auxiliary and Control Circuits

• Use a 500 V megohmmeter.

• Measured value > 2 MΩ.

IV. Fault-Based Maintenance (When Required)

(1) Circuit Breaker Operating Position Alignment

• Apply conductive grease or Vaseline to the inner ring of the moving contact.

• Insert the trolley to the service position and then withdraw it.

• Use a caliper to measure the effective engagement depth between moving and stationary contacts on the visible part: should be 15–25 mm.

(2) Circuit Breaker Repair or Replacement

• Carry out in accordance with manufacturer’s specific technical specifications.

(3) Instrument and Meter Repair or Replacement

• Carry out in accordance with manufacturer’s specific technical specifications.