Switchgear and Controlgear Inspection Checklist

Switchgear and Controlgear Inspection Checklist (Electrical & Mechanical)

Switchgear and Controlgear Visual and Mechanical Inspection

  1. Compare equipment nameplate data with drawings and specifications.
  2. Inspect physical and mechanical condition.
  3. Verify appropriate anchorage, area clearances, and correct alignment.
  4. Inspect all doors, panels, and sections for corrosion and missing hardware.
  5. Verify appropriate contact lubricant on moving current-carrying parts.
  6. Verify appropriate lubrication on moving and sliding surfaces.
  7. Inspect insulators for evidence of physical damage or contaminated surfaces.
  8. Verify correct barrier and shutter installation and operation.
  9. Exercise all active components.
  10. Inspect all mechanical indicating devices for correct operation.
  11. Verify that filters are in place and/or vents are clear.
  12. Perform visual and mechanical inspection on all instrument transformers.
  13. Inspect control power transformers.
  14. Inspect physical damage, cracked insulation, broken leads, tightness of connections, defective wiring, and overall general condition.
  15. Verify correct functioning of drawout contacts and interlocks.
  16. Perform ground-resistance tests on all instrument transformers.
  17. Perform resistance tests through all bus joints with a low-resistance ohmmeter.

Switchgear and Controlgear Electrical Inspection

  1. Perform insulation-resistance tests on each bus section, phase-to-phase and phase-to-ground, for one minute.
  2. Perform an overpotential test on each bus section, each phase to ground with phases not under test grounded.
  3. Perform insulation-resistance tests at 1000 volts dc on all control wiring.
  4. Perform control wiring performance test.
  5. Perform current injection tests on the entire current circuit in each section of switchgear.
  6. Perform current tests by primary injection. Where primary injection is impractical, utilize secondary injection.
  7. Control Power Transformers: Perform insulation-resistance tests. Perform measurements from winding-to-winding and each winding-to-ground Perform secondary wiring integrity test.
  8. Voltage Transformers: Perform insulation-resistance tests. Perform measurements from winding-to-winding and each winding-to-ground Perform secondary wiring integrity test.
  9. Verify operation of switchgear/switchboard heaters if available.
  10. Compare bus connection resistances to values of similar connections.
  11. Check bolt-torque and re-tight.
  12. Microhm or millivolt drop values shall not exceed the high levels of the normal range as indicated in the manufacturer’s published data. If manufacturer’s data is not available, investigate any values which deviate from similar bus by more than 50% of the lowest value.
  13. Insulation-resistance values for bus, control wiring, and control power transformers shall be in accordance with manufacturer’s published data. Values of insulation resistance less than this table or manufacturer’s minimum shall be investigated. Over potential tests should not proceed until insulation-resistance levels are raised above minimum values. The insulation shall withstand the over potential test voltage applied.

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