Motors play a crucial part in the production process for many industries. However, through extended use, motors can become worn and less efficient, driving associated costs up for businesses.
Although many think the cost of the motor itself is the biggest outlay a business faces, studies have found that this makes up just 2% of its life-cycle cost. With maintenance and repairs occupying such a large cost share in relation to electric motors, it’s in your best interest to extend the life of your electric motor wherever you can.
Offering their expert advice, motor rewind specialist, Houghton International, explains the basics of extending your electric motor’s life.
With many intricate rotating parts, lubrication is key to extending the life of your electric motors. 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.
Clearly occupying an important role, issues can arise if your motor is not lubricated at the correct intervals or if over- or under-lubrication occurs. 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.
Extending motor life is largely ensuring the motor is optimally lubricated. 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.
It’s incredibly important that the oil or grease you choose is compatible with your electric motor. 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
- Unusual colour shifts in lubricants
- Foreign particles
- Leaks caused by viscosity changes
- Emulsion formation
- Fluid separation
Of course, the impact will depend on the degree of incompatibility. As a general rule of thumb, use the same oil or grease that is already in the motor bearings.
High temperatures can significantly impact the lifespan of an electric 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.
Ensuring the motor can adequately cool is one way to prevent the motor from overheating. 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.
Monitor temperature changes too, as sudden increases can indicate a problem elsewhere within the motor.
As well as specific tasks like temperature monitoring and lubrication, regular maintenance in general is key to extending the life of electric motors. There are three main types of maintenance: preventative, predictive and reliability-based maintenance.
Through scheduled inspections and tests, preventative maintenance detects potential issues early before they have a chance to take effect. This type of maintenance can include electrical tests, measuring winding resistance and mechanical assessments.
By assessing and identifying trends from preventative maintenance, predictive maintenance is the process of forecasting when corrective maintenance or repairs will need to be carried out. In essence, this allows you to predict the lifespan of the motor’s parts.
Reliability-based maintenance involves evaluating a motor to determine the best combination of maintenance activity to ensure its reliability in the future. This type reduces maintenance to the most cost-effective activities.