Tips for extending your electric motor’s life

Jon Lawson

With maintenance and repairs occupying such a large cost share in relation to electric motors, motor rewind specialist, Autumn Wiberg, shares tips for extending your electric motor’s life

Motors are central to many industry processes. However, through extended use, motors can become worn and less efficient, driving associated costs up for businesses.

Did you know that the initial cost of an electric motor makes up just 2% of its life-cycle cost?

Adequate lubrication

Your motor needs to be adequately lubricated given its many intricate rotating parts.

Whether your motor uses grease or oil, lubricants separate rolling or sliding surfaces, minimising friction and heat to reduce overall wear. They also work to prevent corrosion and contamination.

Over- or under-lubrication can cause major problems with your electric motor.

When under-lubricated, there is not enough oil or grease to protect the motor’s internal parts, leaving it susceptible to wear and tear.

When the opposite occurs and the motor is over-lubricated, shields can become damaged and the oil or grease can lose their lubricating capability, as caused by rising operating temperatures caused by friction.

Optimal lubrication is a key factor in extending the life of your motor. Always lubricate according to manufacturer guidelines or the motor’s lubrication plate.

This will help determine how often you’ll need to oil or grease the motor and the type and grade of the lubrication you’ll need.

You must make sure the oil or grease used is compatible, otherwise your efforts could be fruitless.

Failure to choose the correct grease or oil can have varying degrees of impact, from mildly increased bearing wear to complete machine failure. It can also lead to unusual increases in:

* Heat generation

* Metal wear

* Vibration

* Noise

* Unusual colour shifts in lubricants

* Foreign particles

* Leaks caused by viscosity changes

* Foaming

* Emulsion formation

* Fluid separation

Overall, the higher the level of compatibility, the greater the damage caused. As a general rule of thumb, use the same oil or grease that is already in the motor bearings.

Temperature increases

An increase in temperature could cause significant damage to your motor. There are a number of reasons why temperature may increase, including overloading, under-voltage, over-voltage and improper ventilation.

Because the incorrect temperature can significantly impact the performance of your electric motor, it’s important to monitor and maintain the correct temperature.

Allow the motor to cool and you will likely avoid this type of temperature damage. Keep its operating environment free of dirt and debris to ensure vents do not get obstructed and prevent hot air from being recirculated throughout the motor.

If the temperature increases suddenly, it could be an indication of another problem. Monitor changes to prevent issues from arising.

Regular maintenance

In addition to the above, regular maintenance is important. There are three main types of maintenance: preventative, predictive and reliability-based maintenance.

Preventative maintenance

As the name suggests, preventative maintenance aims to discover issues before they have an opportunity to take effect. This type of maintenance can include electrical tests, measuring winding resistance and mechanical assessments.

Predictive maintenance

Relying on trend analysis, predictive maintenance is the process of forecasting when maintenance or repairs will be required. In essence, this allows you to predict the lifespan of the motor’s parts.

Reliability-based maintenance

Through motor analysis, reliability-based maintenance allows you to establish the most suitable maintenance solution to ensure motor longevity. This type reduces maintenance to the most cost-effective activities.

Autumn Wiberg is a freelance journalist. For more information, contact Houghton International