Electric motors play a significant role in plant operations. Their effectiveness is of utmost importance because if they fail, the entire process gets affected which results in loss of time and revenue. Often it is seen that electric motors are stored during the period of inactivity. When an electric motor is not used for daily jobs, it is crucial to store it properly because an improperly stored electric motor suffers from numerous types of problems. When a spare electric motor is not taken care of, it starts developing signs of corrosion and its lifespan decreases significantly. When an electric motor is expected to be stored, whether sitting on a shelf or palletized, it is important to follow proper storage measures.
From rotating the shafts of stored motors to minimizing their exposure to vibration, there are some tips to help you store spare motor efficiently. While some owners of electric motors employ a warehouse management system, others follow proper maintenance steps. In order to minimize waste and vibration, it is recommended to store motors on wooden pallets. A great idea would be to use the worn conveyor belts as added vibration-absorbing padding material between the pallet and the motor. To ensure that your electric motor is ready to use when needed, consider the following tips to make the most of the inactive motors while in storage.
- For storing motors, always choose an indoor place or closed storage area that is clean, dry, and free from vibration, insects and airborne debris.
- When the motor will be out of service for less than 30 days, store it in a climate controlled environment, preferably 10 to 20 degrees F above room temperature.
- Make sure that the bearing cavities are coated with grease for added protection from moisture. Moreover, make sure to occasionally turning over both sealed and shielded bearings to avoid the grease from settling on one side. Also, the exposed surface should be treated with a rust inhibitor.
- It is recommended to either store electric motors vertically, or rotate them quarterly. When a motor is not stored vertically, a small dent may appear in the bearing’s outer race due to the excess weight of the rotor and shaft assembly.
- In case the humidity level is more than 60 percent, rotate the shaft 10-15 revolutions weekly. Also, make use of any humidity control method or desiccants. If the windings temperature falls below 10° F to 20° F above the ambient temperature, you may need portable heaters or humidifiers.
- Avoid storing spare motors nearby sources of vibration. Storing your electric motor near ambient vibration areas like production floors, busy roads, construction equipment, rail lines, or production areas can cause internal bearings to vibrate.
- It is important to protect your electric motor from pests like insects, rodents, and birds that can enter the motor and cause damage to the insulation winding and can block ventilation and drain openings.
- It is a good practice to turn the shafts annually as part of the procedures to maintain the grease coating on the rollers of the bearing. Semiannual shaft rotation is the most commonly practiced measure for shaft rotation.