Brushless DC motors (BLDC) are widely used in fields such as drones, electric vehicles, and smart home appliances due to their high efficiency, quiet operation, and durability. Even with excellent performance, motors may stop running due to excessive load, aging, or environmental issues. When encountering a fault, one should not blindly replace components, otherwise, it may mask the real cause of the fault. Mastering scientific fault troubleshooting methods is like finding a general practitioner for the motor. By observing symptoms and conducting step-by-step inspections, common problems can be quickly repaired, and the service life of the equipment can be extended. Whether you are an engineer, a maintenance enthusiast, or an ordinary user, understanding these skills will enable you to handle motor faults with ease and prevent the problems from worsening.
Initial Observation: Categorization of Phenomena
The Motor Does Not Rotate at All
Possible Causes: Power supply failure, controller damage, short circuit or open circuit of the motor winding, failure of the Hall sensor.
The Motor Rotates Weakly or Shakes
Possible Causes: Local short circuit of the winding, demagnetization of the magnet steel, abnormal Hall signal, stuck bearing.
The Motor Produces Unusual Noises or Excessive Noise
Possible Causes: Damaged bearing, rotor eccentricity, magnet steel detachment, uneven air gap.
The Motor Overheats Abnormally
Possible Causes: Overload operation, winding short circuit, poor heat dissipation, abnormal controller drive.
Step-by-step Troubleshooting Methods
Initial Inspection with Power Off
Through mechanical inspection and visual inspection, observe whether the shaft rotates smoothly, whether there are any abnormal sounds, and whether the outer shell is intact. At the same time, check whether the cable plug is in good condition.
Electrical Detection
Use a multimeter to detect the resistance value of the winding, check the insulation condition, and use the Hall sensor to detect whether the Hall signal is output normally.
Controller and Power Supply Detection
Check whether the power supply voltage is normal, confirm whether the PWM speed regulation signal and the wiring are accurate, and conduct no-load and temperature rise tests.
Common Fault Cases and Solutions
The Motor Shakes and Does Not Rotate
Troubleshooting: Check whether the winding resistance is balanced and whether the Hall signal is normal.
The Motor Speed is Unstable
Troubleshooting: Check the condition of the magnet steel and whether there are any abnormalities in the controller’s current sampling circuit.
Tools and Alternative Solutions
Essential Tools: Multimeter, screwdriver, etc. If there are no professional tools, preliminary inspections can be carried out through simple methods.
Preventive Maintenance Suggestions
Regular cleaning, avoiding overload, heat dissipation management, and moisture and rust prevention are the keys to keeping the brushless DC motor running normally.Through the above methods and suggestions, you can quickly identify the faults of the brushless DC motor and take corresponding measures for repair, thus extending the service life of the equipment and improving work efficiency.
Troubleshooting brushless DC motors is challenging and requires logical reasoning. Observing the problems and finding the fault points demonstrate the engineering thinking of “divide and conquer”. However, it is important to figure out the cause of the fault – whether it is a design problem, improper operation, or environmental impact? Every troubleshooting is a good opportunity to optimize equipment management.
