How to Troubleshoot Overheating in Induction Motors

How to Troubleshoot Overheating in Induction Motors

Induction motor overheating is common in industrial environments and can lead to insulation damage, reduced lifespan, and equipment failure. Below is a simple guide to help diagnose and troubleshoot the issue.

1. Signs of Motor Overheating

• Motor casing is hot to touch
• Burning smell from windings
• Thermal overload tripping
• Higher operating current
• Reduced torque and poor performance

2. Common Causes of Overheating

2.1 Electrical Causes

• Motor overload
• Voltage imbalance or single phasing
• Low voltage or fluctuation
• Poor power quality or harmonics
• Incorrect frequency (especially below 30 Hz)

2.2 Mechanical Causes

• Bearing failure
• Misalignment
• Cooling fan damage
• Blocked ventilation
• Mechanical overload

2.3 Environmental Causes

• High ambient temperature
• Dust or moisture
• Poor airflow around motor

3. Troubleshooting Steps

Step 1: Check Motor Load

Measure running current on all phases. If above 80–90% of FLA, the motor may overheat. Reduce load or use a higher-rated motor.

Step 2: Check Voltage Supply

Ensure balanced voltage and no single phasing.

Voltage Imbalance Formula:

Voltage Imbalance % = (Max deviation from average voltage / Average voltage) × 100

Step 3: Check Cooling and Ventilation

• Inspect motor cooling fan
• Clean ventilation openings
• Ensure no objects block airflow

Step 4: Check Vibration and Alignment

• Inspect bearings
• Check alignment
• Confirm no excessive vibration

Step 5: Check VFD Settings (If Applicable)

Motors running below 30 Hz lose cooling efficiency.

Torque ∝ V² / f

Step 6: Internal Inspection

• Check winding resistance
• Perform insulation test (Megger)
• Inspect stator and rotor for burn marks

4. Preventive Measures

• Regular bearing lubrication
• Clean motor surfaces monthly
• Perform vibration analysis
• Use proper cooling and ventilation
• Maintain stable voltage supply

If your induction motor is overheating or requires professional inspection, repair, or overhaul, KH Venture provides complete motor maintenance services including troubleshooting, rewinding, alignment, vibration checks, and on-site support.

Contact KH Venture today for service and maintenance support.