Maintenance of Motors which Help in Energy Conservation
Maintenance :
- Inadequate maintenance of motors can significantly increase losses and lead to unreliable operation for example, improper lubrication can cause increased friction in both the motor and associated drive transmission equipment.
- Resistance losses in the motor, which rise with temperature, would increase.
- Providing adequate ventilation and keeping motor cooling ducts dean can help dissipate heat to reduce.
- The life of the insulation in the motor would also be longer : for every 10°C increase in motor operating temperature over the recommended peak the time before rewinding would be needed is estimated to be halved.
- A list of good maintenance practices to help insure proper motor operation is as follows :
- Inspecting motors regularly for wear in bearings and housings (to reduce frictional losses) and for dirt /dust in motor ventilating ducts to ensure proper heat dissipation).
- Checking load conditions to ensure that the motor is not over or under loaded. A change in motor load from the last test indicates a change in the driven load the cause of which should be understood.
- Lubricating appropriately. Manufacturers generally give recommendations for how and when to lubricate their motors. Inadequate lubrication can cause problems, as noted above. Over- lubrication can also create problems e.g. excess oil or grease from the motor bearings can enter the motor and saturate the motor insulation, causing premature failure or creating a fire risk.
- Checking periodically for proper alignment of the motor and the driven equipment Improper alignment can cause shafts and bearings to wear quickly, resulting in damage to both the motor and the driven equipment.
- Ensuring that supply wiring and terminal box are properly sized and installed. Inspect regularly the connection at the motor and starter to be sure that they are clean and tight.
Age :
- In India, most motor cores are manufactured from silicon steel or de-carbonized cold-rolled steel, electrical properties of which do not change measurably with age.
- However, poor maintenance, e.g. inadequate lubrication of bearings, insufficient cleaning of air cooling passages, etc. can cause a deterioration in motor efficiency over time
- Ambient conditions can also have a detrimental effect on motor performance.
- For example, excessively high temperatures, high dust loading, corrosive atmosphere, and humidity car impair insulation properties, mechanical stresses due to load cycling can lead to misalignment. However with adequate care, motor performance can be maintained.