There are many reasons why electric motors need preventive maintenance, as it is a vital part of improving an electric motor’s overall functionality and, most importantly, its effective lifespan. When developing such a maintenance routine, numerous factors, including special environmental conditions, types of driven equipment, loading, run times, and ambient operating temperatures. And while no one plan can fit them all, several standard procedures are common to most maintenance programs.
Below, we go over the essential procedures in your motor preventive maintenance plan.
1. Aligning the motor
Motor alignment lessens the stress on the electric motor and driven equipment. Dial indicators or annual laser alignments help identify any misalignments that may have occurred from worn or damaged couplings, broken shafts, overheating issues, seal wear, bearing failure, and other types of issues. While the two alignment devices have pros and cons, they are nonetheless effective at realigning motors.
Dial indicators are the best option when working in tight spaces and are great in all lighting conditions, but they require more attention and calculations to do the alignment. Meanwhile, laser alignments eliminate most of the guesswork in removing and adding shims but can often prove difficult in tight spaces and under certain lighting. Choose the right alignment device for your motor for the best results.
2. Filter cleaning
Filters are vital in keeping dirt, dust, and debris out of the electric motor, preventing them from impacting its life span and keeping them cool. Other abrasives like sand that enters the stator area and rotor at high velocity turn into a sandblaster that erodes the stator and rotor, which is what filters help to prevent.
These filters are further categorized as main and pre-filters that capture these contaminants, but they are only as effective if cleaned regularly. Clogged filters starve electric motors from getting cool air, causing overheating issues that lead to shutdowns and potential damage.
3. Vibration analysis
Vibration analysis of motors and other equipment is a broad topic best covered separately. The base readings it produces can show electrical issues, wear, deterioration, misaligned or loose equipment, and so on, allowing operators to pinpoint the specific issues affecting an electric motor. This data becomes invaluable in troubleshooting after the correct issue is identified.
4. Electrical testing
Annual electrical inspections and testing are integral to rooting out early issues like loose terminations, failing winding insulation, moisture in the windings, and so on to prevent further deterioration. Electrical testing can also prevent potential failures during startup. Testing Resistance Temperature Detectors for the stator and bearings via monitoring equipment helps avoid false temperature readings and unplanned shutdowns. Lastly, electrical testing is used to verify the proper functioning of space heaters that keep moisture out of the motor when it is idle. From these inspections, problems like failing taped connections, loose terminations, rubbing, visible wear, and more can all be handled before they cause motor failure.
5. Bearing lubrication
Bearings come in many shapes and sizes, but all need regular lubrication with oil or grease. Servicing greased bearings can be done manually or via an automated procedure with programmable auto-lubers that supply bearings with a set amount of grease over time.
Meanwhile, oil bearings require periodic oil changes to maintain the proper oil viscosity that keeps them cool and lubricated. These changes also act as a health check that shows whether contaminants or metal particulates have entered the bearing chamber, indicating excessive wear.
Conclusion
On top of electric motor rewinds, preventive maintenance is another crucial part of improving electric motors. These procedures represent some of the more basic things to consider when creating a preventive motor maintenance plan. If taken into consideration, along with the conditions the motor operates in, operators can tailor a plan specifically to keep your electric motors running better for longer and more cost-effectively.
