Power Electronical

Other Details

Motor Rotor eccentricity Motor Rotor Bar Cracks

Misalignment or Bend Shaft

Motor Rotor Bar looseness

Foundation defect / soft foot

Electrical defect in motor

Mechanical looseness

Defective belt drives

Unbalance in a Rotor

Damaged Bearings

Gear defects

Resonance

Winding Resistance Measurements: 

The test is most effective when compared with such measurements

10 RLA/Testing of H. T. Motor/Generator from similar motor/generator, or previous test results or factory test data. It gives the full information of abnormalities like loose connections, broken strands etc. It even identify other issues like unbalance that result in overheating & circulating events.

Insulation Resistance Polarization Index [IR/PI]:

Insulation Resistance and Polarization Index is the most commonly Practiced and accepted test in identifying dryness/wetness of paper insulation. The life of motor/generator is mainly based or is very sensitive to amount of moisture content in paper insulation. This test gives information on aging condition or status of the insulation, moisture content in paper and hence is a very important test for identifying residual life.

Dielectric Loss Measurement (Capacitance & Tan-Delta):

A high loss may indicate problems in the insulation structure. Normal aging of an insulating material will cause dielectric loss to increase. Contamination of insulation by moisture or chemical substances may cause losses to be higher than normal. Physical damage from electrical stress or other outside forces also affects the level of losses. A dielectric loss testing program provides several important benefits. Periodic tests performed during the service life of the equipment can indicate that the insulation is either aging normally or deteriorating rapidly. Diagnostic tests may disclose the location of a fault, or the reason for failure.