Sudden stoppage of DC brushless motor during operation.
A sudden stoppage of a brushless DC motor during operation usually indicates an abnormality in some part of the system. Due to the high dependence of BLDC motors on electronic control systems, their stalling may be caused by various factors such as power supply, motor body, driver, control signals, overload protection, etc. The following are common problem classification analysis and handling suggestions:
1、 Power issue
Power interruption or poor contact
Loose or broken power cord or poor plug contact;
Power supply failure or sudden power outage;
Fuse blown, power switch tripped.
Solution: Check if the power connection is secure, test if the voltage is stable, and replace the power module or fuse if necessary.
Voltage too high or too low
The voltage exceeds the range that the brushless DC motor or driver can withstand, causing the protection mechanism to trigger;
The voltage drop of long-distance power supply lines is too high.
Solution: Use a regulated power supply to ensure that the voltage meets specifications (such as rated 24V ± 10%) and avoid sudden changes.
2、 Driver protection triggered
overcurrent protection
Sudden increase or jamming of motor load;
Short circuit of phase line or aging and leakage of winding.
overheat protection
Long term full load operation, automatic shutdown due to high temperature of the drive or motor.
Undervoltage or Overvoltage Protection
The input voltage exceeds the set protection range.
Hall signal abnormality
Hall sensor damage, loose wiring, or signal drift;
The phase of the Hall signal is incorrect, and the driver cannot switch phases properly.
Solution: Check the driver status indicator light or error code, determine the protection type based on the instruction manual, check the driver wiring, current settings, and fault records.
3、 Motor body malfunction
Winding open circuit or short circuit
May be caused by prolonged high temperatures or insulation aging.
Bearing stuck
Poor lubrication of bearings, ash ingress, overload wear, etc., lead to mechanical blockage.
Loss or demagnetization of rotor magnetic steel
Affects the uniformity of the magnetic field, causing the motor to lose step or even lock up.
Solution: Use a multimeter to check if the winding resistance is consistent, rotate the shaft smoothly by hand, and disassemble and inspect the internal structure.
4、 Control signal loss or abnormality
PWM signal interruption or interference
The output signal of the controller is blocked, poorly connected, or has communication errors;
Interference noise causes transient interruption of control signals.
The enable signal suddenly shuts down
Control system misoperation or fault protection action to shut down the driver.
Solution: Check the output logic of the controller, confirm whether the enable signal and communication line are normal; An oscilloscope can be used to observe whether the signal waveform is continuous.
5、 Abnormal load or mechanical blockage
Sudden overload or jamming of the load
Causing a sudden increase in the operating current of the brushless DC motor to trigger the driver protection.
Coupling, gear or transmission mechanism stuck
Loose fasteners, foreign objects stuck or insufficient lubrication.
Solution: After power failure, manually rotate the load system to confirm if there is any mechanical jamming; Check if the coupling and shaft system are coaxial or loose.
6、 Environmental factors
High or low temperature environment
Causing internal protection actions of the driver or motor.
Moisture or dust pollution
Causing PCB board short circuit, Hall interference, and poor connector contact.
Solution: Use sealed motors (IP54 or IP65 rating) in high humidity and high dust environments, and regularly clean the wiring terminals and heat sinks.
7、 Programming and configuration errors
Improper configuration of driver parameters
If the current limiting setting is too low, the voltage protection value is too narrow, and the control mode conflicts.
Control logic interrupt
The upper computer software logic is abnormal, the program is interrupted, or there is a power failure and restart.
Solution: Check if the driver parameter settings match the actual motor model and workload, and verify if the control program is running stably.
summary
When a brushless DC motor suddenly stops running, it is mostly related to protection mechanism triggering, power supply abnormalities, control signal failures, or mechanical load jamming. Suggest starting with the following steps for troubleshooting:
Check the stability of the power supply and the reliability of the wiring;
Observe the driver status light or error code prompt;
Use a multimeter to measure whether the motor winding and Hall signal are normal;
Gradually isolate the control system and load system for testing;
Analyze signal quality and PWM integrity through an oscilloscope.
Timely investigation of the root cause of faults can help extend the service life of brushless motors and improve the reliability of system operation. If the issue still cannot be resolved, it is recommended to contact the motor manufacturer or driver supplier for technical support.
