U.S. Department of Energy - Energy Efficiency and Renewable Energy
Federal Energy Management Program – Operations and Maintenance
Motors
Motor systems consume about 70% of all the electric energy used in the manufacturing sector of the United States. To date, most public and private programs to improve motor system energy efficiency have focused on the motor component. This is primarily due to the complexity associated with motor-driven equipment and the system as a whole. The electric motor itself, however, is only the core component of a much broader system of electrical and mechanical equipment that provides a service (e.g., refrigeration, compression, or fluid movement).
Energy Efficiency Tip
An electric motor performs efficiently only when it is used and maintained properly. Motor efficiencies vary with motor load, and the efficiency of a constant speed motor decreases as motor load decreases. Efficiency can be increased if you turn off unneeded motors; reduce motor system usage; size motors appropriately; and replace small motors, instead of rewinding them.
Cost Savings Tip
Cost savings can be generated if you use strategies to reduce motor system use. For example, you can reduce loads on the HVAC system by improving building shell, manage restorations, improve HVAC conditions, and check the refrigerant charge. Other suggested strategies might be to reduce refrigeration loads; check ventilation systems for excessive air; improve compressed air systems, and repair duct leaks.
Maintenance Tip
There are a number of types of diagnostic tools that can be used to assess motor efficiency. Diagnostic tools can help identify operational efficiency, and assist in the operational and maintenance decision-making process. Please visit our Tool Box to see descriptions of four types of motor diagnostic tools.
Safety Tip
Select motors appropriate for the work area. Consider working conditions, being careful to identify appropriate motors that will operate in a potentially gaseous or explosive area. Check motor classification to match your needs to motor specifications. For example, there is a new line of motors with special coatings that resist the elements.
Numerous studies have shown that opportunities for efficiency improvement and performance optimization are actually much greater in the other components of the system—the controller, the mechanical system coupling, the driven equipment, and the interaction with the process operation. Despite these significant system-level opportunities, most efficiency improvement activities or programs have focused on the motor component or other individual components.