An electric motor operates in a simple and reliable manner, and this can sometimes lead to overlooking the day-to-day maintenance. An electric motor that is well cared for will last for years and provide you with ongoing reliability. The key to reliable operation of motors is having a checklist in place in the form of a preventive maintenance program.
A checklist will make it possible for your employees to know exactly what needs to be examined, corrected or replaced, if need be. Additionally, a checklist will consist of maintenance that will cover tasks such as cleaning, lubrication, inspections, and testing in order to ensure the motor is in good working condition at all times.
The brushes and commutators of an electric motor are prone to wear and tear and, therefore, it is important for your workforce to inspect them for excessive wear. If these two elements are excessively worn, they will not work properly and should be changed immediately.
During the maintenance process, the operator must check the type, hardness, conductivity, and spring pressure of the brushes. A commutator in good condition is expected to have a smooth appearance with no scratches or grooves. Brush sparking usually causes the commutator to be blackened and rough. Moreover, your employees should inspect the motor mount, rotor, stator, and the belts.
The checklist should also cover inspection of bearings. One of the most common causes of electric motor failures is bearing failure. Typical bearing problems include insufficient lubrication, worn bearings, hot motor, excessive loading, harsh external environments, or replacement with the wrong bearing type.
Maintenance tasks will depend on the type of bearings used, motor application and operating environment. On motors that are heavily used, it is imperative to check the bearings daily using an infrared scanner or a stethoscope. Check the temperature of the bearing housing or surface using a thermometer or an electronic temperature sensing device. Make a comparison between the temperature of normally operating bearings and hot bearings. If the bearing is too hot to the touch, that might be an indication that it is malfunctioning, which, if left unattended, can halt the operation of the motor.
Your electric motor should be lubricated on a regular basis according to manufacturer’s instructions. Ensure that the oil is changed at least once a month if your motor is operated in poor environments. Be careful to never over-lubricate since excessive lubricants deteriorate insulation. Only use the grease or oil that’s specified for the machine to ensure the proper functioning.
Excessive vibrations are difficult to detect by hand, but can significantly shorten the life of your electric motor. This is because it can lead to failure of windings or metal fatigue of parts. Excessive vibration can be a result of a defective sleeve, improper balance, misalignments, or excessive belt tension. Additionally, if one of the rotating parts is unbalanced, it can create excessive vibration. In order to test the motor and determine the level of vibration, the load should be uncoupled and belts removed before running the motor.
Anyone dealing with the maintenance of electric motors should be very careful given the hazardous nature of electricity. In fact, someone who doesn’t have the proper training in handling electrical components must never carry out maintenance practices.
If the parts are incorrectly assembled or disassembled, it could result in explosions or fires that could threaten human life and property. Unqualified personnel should never be allowed to enter the room or operate the equipment. Moreover, the necessary protective gear should be worn including dielectric tested gloves and approved electrical test devices.
Your employees should be able to carry out daily do-it-yourself maintenance practices on electric motors. This may include practices such as keeping the motor free of dirt, checking for signs of excess wear and ensuring the belts and pulleys are aligned correctly at all times. They should also assess the level and type of noise, carry out lubrication checks, and ensure there are no loose electrical terminals.
Are you interested in teaching your employees how to maintain and troubleshoot common problems associated with the operation of electric motors? Well, now is the time to bring in accredited educators and you can get that at NTT Training. Don’t wait, connect with NTT today for more information.
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