What is the cause of motor overcurrent

The main reasons for motor overcurrent can be divided into the following: high or low voltage, unbalanced three-phase power supply, winding short circuit or open circuit, rotor failure, overload operation, sudden load change, shaft eccentricity, high ambient temperature, and direct starting of large loads.

The main causes of motor overcurrent can be divided into the following five categories, including electrical faults, abnormal loads, and external environmental influences:

Power Problem

Voltage too high or too low: Abnormal voltage can cause an abnormal increase in motor current, and it is necessary to use a voltage regulator or adjust the power supply to match the rated voltage of the motor.

Unbalanced three-phase power supply: Asymmetric voltage may cause overcurrent, and the balance of the power supply circuit needs to be checked.

Internal motor malfunction

Winding short circuit or open circuit: Short circuit can cause a sudden surge in current, while open circuit may cause overheating due to poor contact.

Rotor failure: If the rotor is stuck or the bearing is damaged, it can cause overcurrent due to increased mechanical resistance.

Abnormal load

Overload operation: When the load exceeds the rated power of the motor, it is necessary to reduce the load or upgrade the motor.

Load mutation: Sudden increase in mechanical resistance (such as stalling or jamming) can cause instantaneous overcurrent.

Mechanical and External Environment

Axis eccentricity: Misalignment between the rotor and stator axis can lead to unbalanced torque, causing vibration and overcurrent.

High ambient temperature: High temperature will reduce the insulation resistance of the motor and increase the current.

Inappropriate startup method

Directly starting large loads: a soft starter or frequency converter should be used to gradually increase the speed to avoid instantaneous overcurrent.

Suggestion for handling: Prioritize checking the power supply and winding status, match the load reasonably, regularly maintain the motor, and control the working environment temperature. If overcurrent occurs frequently, it is recommended to contact professional technicians to investigate internal faults.

Key words:

frequency converter,stator,rotor,electrical machinery,soft starter

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