Most companies are constantly looking for ways to save energy. It's a quest that never ends. But you don't have to tackle it all at once. Older motors — even those that were customized for a particular system/application or those no longer in production — can be made more energy-efficient through the use of variable frequency drives (VFDs). VFDs provide a simple, cost-effective way to control a motor's speed or torque by varying the power output. In doing so, they can not only improve process control; they also save energy.
If the motor output is restricted through dampers or other throttling mechanisms, a VFD can save even more in energy costs by precisely matching capacity to demand and eliminating needless energy waste.
If a new motor is a logical replacement for an older motor, the potential for energy savings is even greater. New NEMA Premium motors offer 5-7% higher efficiency for smaller motors (10 HP or less). So replacing an older standard efficiency motor with a new NEMA Premium efficiency motor controlled by a VFD could yield impressive energy savings.
But controlling a motor with a VFD can also shorten the motor's life. 
VFDs create damaging voltages on the shafts of the motors they control. Without proven, long-term shaft grounding, these voltages can discharge through motor bearings, causing electrical discharge machining in the form of pitting (tiny fusion craters in metal surfaces), frosting (widespread pitting), fluting (washboard-like ridge in the race wall), and complete bearing failure — in as little as 3 months! Bearing or motor replacement costs and unplanned downtime can easily wipe out any energy savings from using VFDs.
AEGIS® Shaft Grounding Rings combine direct contact and proprietary non-contact technology to provide superior grounding and protect motor bearings for their full L-10 life. AEGIS Rings channel these damaging voltage discharges away from bearings and safely to ground, protecting VFD-driven motors and the energy savings they generate.
You can easily install AEGIS Rings yourself on any motor (even those with shaft shoulders, slingers, or other end bell protrusions), or have your local motor repair shop install them. But the simplest way to prevent VFD-induced bearing damage is to purchase a new motor with AEGIS Rings factory-installed from the manufacturer. In fact, most major motor manufacturers offer motors factory-equipped with AEGIS Rings.
So, if you are working to make your building, systems, or processes more energy-efficient, remember you don't have to replace all your motors at once. You can replace older, less efficient motors (as they wear out) with new VFD-controlled NEMA Premium motors equipped with AEGIS Shaft Grounding Rings.
For more information on how VFDs can damage motor bearings, click here.
For more information on AEGIS Ring Universal Mounting Kits, click here.
For more information on how AEGIS Rings protect VFD-driven motors, click here.
For a list of manufacturers that offer motors with AEGIS Rings factory-installed, click here.