Ensuring an electric motor remains consistently reliable and operational for years is only possible if it is well cared for. One of the proven ways to provide such care is by having a preventive maintenance program in place and, most importantly, a checklist for day-to-day maintenance. Following a checklist prevents overlooking even a single aspect of the motor and ensures employees know exactly what needs to be examined, replaced, or corrected soon through services such as electric motor overhauling or rewinding. Additionally, it will cover tasks such as general cleaning and inspections, lubrication, and testing to guarantee the motor is always in good working condition. Below, we cover which items are indispensable when making your own list.
Brush and commutator inspection
The brushes and commutators of a motor are among the key components that are highly prone to wear and tear. Thus, they must be frequently inspected for excessive wear to ensure timely replacements and avoid issues when they no longer work properly.
During the maintenance process, operators must check the brushes’ conductivity, spring pressure, and hardness. Commutators that are still in good condition are expected to have a smooth appearance, free of scratches or grooves. Otherwise, they will appear rough and blackened due to brush sparking.
Given that bearing failure is one of the most common causes of failure in electric motors, regular monitoring of this critical component should be a no-brainer. Some typical problems that affect motor bearings include excessive wear, excessive loading, insufficient lubrication, hot motor, harsh operating environments, and using a replacement bearing of the wrong type.
Maintenance tasks will depend on the motor’s application, the type of bearings used, and the operating environment. For motors that see heavy usage, checking on these bearings must be done daily, ideally with the help of an infrared scanner. Similarly, monitor the bearing housing using a thermometer or any other temperature-sensing device.
Frequent monitoring helps establish a baseline for how hot the motor’s bearing gets during normal operation and makes it easier to detect when it gets hotter than usual. When this temperature spike happens, that is usually an indication that the bearing is malfunctioning and will eventually cause a failure if left unattended.
It should go without saying that electric motors need regular lubrication as per the manufacturer’s instructions to function properly. In particular, motors operating in poor environments should receive an oil change at least once a month. That said, never over-lubricate since applying too much lubricant deteriorates insulation. Lastly, only use the oils recommended for your motor to ensure proper functioning.
Excessive vibrations are notorious for significantly shortening the life of electric motors, as they can cause winding failure and metal fatigue on other components. This problem can stem from many causes, including a defective sleeve, misalignments, improper balance, and even excessive belt tension. Testing a motor to determine its vibration levels first requires uncoupling the load and removing the belts before running it.
Preventative maintenance is one of the best ways of keeping operating costs to a minimum, as it keeps unnecessary and costly repairs at bay and maintains the uptime of your most critical assets. That said, a maintenance program is only effective if it is followed to the T, so having a checklist that covers all the aspects that need checking daily, weekly, monthly, and so on is indispensable. Incorporating specialised procedures, such as electric motor testing, into the maintenance program could also enhance the overall reliability and longevity of critical equipment.