What Causes a Brushless DC Motor to Overheat?

When using brushless DC motors, we may encounter faults such as motor overheating or smoke. What are the reasons for such problems? How to solve them? Let's discuss brushless DC motor overheating together.

BLDC motor with a controller

How to troubleshoot BLDC motor overheating?

  • If the BLDC motor voltage is too high or too low, the temperature rise will be too high.
    If the power supply and voltage do not meet the requirements, please contact the power supply department for solutions.
  • When the wire is burned, the iron core is burned, which increases the iron consumption.
    At this time, the iron core should be checked and tested, the iron core should be repaired, and the fault should be eliminated.
  • The friction between the stator and rotor cores causes the brushless DC motor to overheat.
    If the bearing clearance exceeds the limit, a new bearing should be replaced. If the rotating shaft is bent, investigation and treatment are required. When the iron core is loose or deformed, the iron core should be treated.
  • The surface of the winding is covered with dirt or foreign matter, which affects the heat dissipation of the brushless DC motor.
    Clean or clean the BLDC motor regularly, and keep the ventilation ditch of the brushless DC motor unblocked.
  • The brushless DC motor is overloaded or the dragged production mechanical resistance is too large, which makes the brushless DC motor heat up.
    Eliminate the failure of the dragging machinery and reduce the resistance. According to the current indication, if the rated current exceeds the rated current, the load should be reduced, and the larger capacity BLDC motor should be replaced or capacity increase measures should be taken.
  • The brushless DC motor starts frequently or has too many forward and reverse rotations.
    Reduce the number of brushless DC motor starts and forward and reverse rotations or replace a suitable BLDC motor.
  • The cage rotor is broken or the winding of the winding rotor is loose, and the rotor of the brushless DC motor is heated under the rated load, which makes the temperature rise of the brushless DC motor too high.
    Find out the broken bar and loose place, and re-weld or tighten screws.
  • Short circuit between turns of winding, short circuit between phases and winding grounding.
    Check to confirm, troubleshoot or replace the brushless motor.
  • The inlet air temperature is too high.
    Check whether the cooling system device is faulty, and check whether the ambient temperature is normal.
  • The brushless motor operates in two phases.
    Check the melted wire, switch contact points, and troubleshoot.
  • Poor impregnation of the winding after rewinding.
    To adopt the secondary impregnation process, adopt vacuum impregnation measures.
  • The ambient temperature is increased or the ventilation passage of the brushless motor is blocked.
    Improve the ambient temperature, take cooling measures, isolate the high-temperature heat source near the BLDC motor, and avoid the brushless motor from being exposed to sunlight.
  • Wrong winding connection.
    The Y-connected brushless motor is mistakenly connected to a △ connection or the △-connected brushless motor is mistakenly connected to a Y connection, please correct the wiring.

The above are all the reasons and solutions for brushless DC motors overheating. Hope it helps everyone! Brushless.com will keep you updated with information about brushless motors.

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