Why do electrical motors fail?

Electrical motors are an essential part of modern manufacturing – they provide power for machines and equipment and keep operations running smoothly. They are versatile and a reliable source of power, used in a range of applications, and as manufacturing plants continue to automate the demand for electrical motors is expected to grow.

It’s important they stay running at peak performance levels to prevent downtime and increase efficiency. However, like any other piece of equipment they can fail for various reasons. Understanding why these failures happen will help ensure their reliability and longevity and keep your operations running for longer.

Common reasons for electrical motor failure:


This is the most common cause. This can occur due to factors like excessive current, prolonged high load, inadequate ventilation, or ambient temperature exceeding the motor's rating. Overheating damages the motor's insulation, windings, and bearings.

Bearing failure

Motor bearings support the rotor and can wear out due to continuous operation, misalignment, improper lubrication, or the ingress of contaminants. Bearing failure can cause vibration, noise, and eventually, motor malfunction.


Operating a motor beyond its rated capacity can cause excessive stress on the components, leading to premature failure. Overloading may occur due to design miscalculations, process changes, or unexpected mechanical issues.

Frequent stop-start cycles

Frequent starting and stopping of motors can cause mechanical stress on the windings and bearings. This phenomenon, known as "motor cycling," can lead to fatigue and premature failure.

Contaminants and environmental factors

Dust, dirt, moisture, or chemicals can infiltrate the motor, affecting its components and insulation. Harsh environmental conditions, such as corrosive atmospheres, can also contribute to motor failure.

Electrical surges and voltage spikes

Sudden increases in voltage, known as surges or spikes, can damage the motor's insulation and windings. These surges can occur due to lightning strikes, switching events, or power grid issues.

How to prevent electrical motor failure

To prevent motor failures, it's necessary to adhere to proper maintenance schedules, monitor operating conditions, address mechanical issues promptly, and ensure that the motor operates within its rated capacity and environmental limitations. Regular inspections, temperature monitoring, and vibration analysis can help detect early signs of potential failures, allowing for timely maintenance or replacements.

Wittenstein’s condition monitoring will help with machine maintenance and reliability and their solutions will provide a much better understanding of the health and condition of your components and enable you to plan maintenance at convenient times, plus purchase any required replacements without causing expensive downtime.

Watch how it works in the video below

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Posted: 02/08/2023 11:22:00 by Leah McLaurin | with 0 comments