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TESTING OF THREE PHASE INDUCTION MOTOR

TESTS WHEN ISOLATED

1) VISUAL TESTS:

  • Check that motor frame is mechanically sound. 
  • Remove terminal cover plate and check for ingress of foreign material, moisture etc. 
  • Check for signs of overheating, arcing or burning. 
  • Check ventilation is clear. 

2) ELECTRICAL TESTS:

  • Identify windings using a continuity tester. 
  • Measure the resistance of the windings ( 3 identical readings ). 
  • Measure the insulation resistance between each winding and between windings and frame. 

3) MECHANICAL TESTS:

  • Check that the rotor is free to rotate and does so smoothly / quietly.
  • Check that motor interior is free of dirt, dust, water and oil.
  • Check for play in bearings.

4) TESTS WHEN RUNNING:

  • Check run currents ( If uneven check voltage at motor terminals ). 
  • Check speed of motor at no load and full load. 
  • Check vibration levels and noise levels. 
  • Check for temperature hot spots.

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