How to determine if motor windings are damp or aged?

How to Determine if Motor Windings Are Moist or Aged?

• To determine if motor windings are moist, use the following methods:

  
  

• Visual Inspection: Check the winding surface for condensation, water droplets, or signs of moisture.

  
  

• Insulation Resistance Measurement: Use a megohmmeter to measure the winding's insulation resistance. If the resistance value is significantly below the normal range, moisture may be present.

  
  

• Comparison After Drying Treatment: Perform drying treatment on the motor (e.g., oven drying), then measure the insulation resistance again. If the resistance value increases significantly, moisture can be confirmed.

Methods for determining motor winding aging include:

• Observe winding color: Aged windings may darken or even exhibit charring.

  
  

• Check winding flexibility: Aged windings become brittle and prone to fracture.

  
  

• Inspect the insulation layer: Cracks, peeling, or brittleness may appear in the insulation.

  
  

• Measure the DC resistance of the windings: Compare the resistance value to original specifications or a normal motor. Significant deviation may indicate winding aging.