4 FM quick reads on motors
1. Motors Can Help Drive Energy Efficiency
The first step for managers trying to determine the best application of premium-efficiency motors is to develop a plan that phases in upgrades of existing motors.
The first step is to identify all motors in the facility. For each motor, record nameplate data, including the motor's horsepower (hp), operating voltage, and operating speed. If the motor is a constant-speed model, measure and record its amperage and power factor, and identify the load it drives and the hours it operates annually, noting if the load is constant or variable.
Motors and the loads they drive represent some of the largest energy users in institutional and commercial facilities today. With many of these loads operating 24 hours a day and 365 days a year, maintenance and engineering managers looking for ways to improve their facilities' operating efficiency are focusing their attention more often on their facilities' motors, where even a small increase in efficiency can result in significant savings.
Today's new-generation motors are quite different from most motors installed in facilities. Improvements in their design and manufacturing have resulted in improved operating efficiencies.
One factor driving this improvement has been mandatory standards for motor performance. The Energy Independence and Security Act of 2007 established the minimum performance standards for a range of motors commonly found in facilities.
As manufacturers have improved their processes by using higher-quality materials and manufacturing techniques, many of the motors available today go beyond these minimum standards. As a result, managers have access to a expanded range of premium-efficiency motors.
Although these motors cost 10-15 percent more than standard-efficiency motors, managers can recover the additional first costs through energy savings, particularly in applications where the motor runs for more than 4,000 hours annually. Managers can expect to achieve a simple two-year payback. In most applications, operating efficiencies will increase 2-8 percent.
Improving Motor Efficiency
I'm Steve Schuster, associate editor of Maintenance Solutions magazine. Today's topic is motor efficiency.
Motors and the loads they drive represent some of the largest users of electricity in commercial and institutional facilities. Because motors are such high users of energy, they present a tremendous opportunity for maintenance and engineering managers to reduce energy use and cost through improved motor efficiency.
Much has happened recently that gives managers tools to improve motor efficiency. The federal government has developed energy standards that manufacturers must meet for the types of motors commonly found in a facility's energy-using systems. Replacing standard-efficiency motors with high-efficiency motors will reduce the energy requirements for that motor by about 2-8 percent. While that might not seem like a major improvement, depending on the horsepower of the motor and the number of hours it operates annually, the energy savings can be significant.
All of these energy-efficiency improvements come at a cost, however. The typical high-efficiency motor typically costs 10-15 percent more than the standard-efficiency motor it replaces. Premium-efficiency motors cost even more. But to help offset this increased cost and provide managers with the incentive to upgrade to more efficient motors, some utilities offer rebates and other incentives that can be as high as $50 per horsepower (hp).
Managers should evaluate their options based on the particular application. The amount of money they can save will depend not only on an improvement in operating efficiency but also on local utility rates and the annual number of hours of operation for that particular motor.