How To Prevent Motor Burnout

In daily work, you must have encountered many cases of motor burnout. Some are caused by mechanical faults, some by thermal relay failures, and others by single-phase operation. So how can we avoid such failures?

Keep the motor clean During motor operation, there shall be no dust, water stains or debris within a 3-meter radius around the air inlet. Otherwise, once sucked into the motor, these contaminants may form conductive media or damage the wire insulation, resulting in inter-turn short circuits and motor burnout.

To ensure safe motor operation, the motor and its surrounding environment must be kept clean. This allows the motor to maintain a safe and stable operating condition during long-time running.

Keep the motor operating within rated current Motor overload usually arises from excessive driven load, low supply voltage, or jamming of the coupled machinery. If overload persists for a long period, the motor draws a large amount of active power from the power grid. The current rises rapidly and temperature increases accordingly, which can easily burn out the motor.

Therefore, the motor shall operate within rated current at all times. It is also necessary to inspect the operation of transmission equipment, the alignment of couplings, gear drives and other components.

Monitor motor temperature Operators shall regularly check the temperature of bearings, stator, housing and other parts of the motor. Special attention shall be paid to temperature rise monitoring for motors without voltage, current, frequency monitoring or overload protection. Shut down immediately if excessive temperature rise is detected for inspection.

In addition, rolling elements, raceway surfaces and clearances of bearings need regular inspection. Replace bearings before resuming operation once any abnormality is found.

Watch for vibration, abnormal noise and unusual odour Motor vibration will increase the vibration level of connected loads, adding extra load on the motor. Overloaded operation may lead to burnout. Noise and strange odours are early warning signs of motor faults and must be closely monitored.

During motor operation, especially for high-power motors, frequent inspections are required. Check whether end covers, foundation bolts, bearing retainers and other fasteners are loose. Troubles shall be fixed promptly once found.

Ensure proper function of starting equipment Generally speaking, the condition of starting equipment determines whether the motor can start normally. Experience shows that most motor burnout incidents are caused by faulty starting equipment, such as single-phase starting and arcing at contactor contacts.

How to maintain starting equipment? The main tasks are cleaning and tightening. Dirty contactor contacts increase contact resistance, causing overheating and motor burnout, which may further damage the motor. Therefore, always keep starting equipment clean and fasten connections. The electrical control cabinet shall be installed in a dry, well-ventilated and accessible location with regular dust removal.