Electric motors are essential to modern mining. From conveyors and 
crushers to electric trucks and loaders, to pumps and the HVAC equipment that keeps the air breathable, all are run by motors. When a motor fails, production will be slowed or even shut down until it is repaired or replaced. So obviously, preventing motor failure is a good thing.
Electric motors nowadays are often controlled by variable frequency drives, for several reasons. But despite their advantages, drives have their drawbacks, too. They can cause premature motor failure, by damaging both the motor windings and the motor bearings. When the motor is far from the drive - as is often the case in mines - both of these problems are worsened.
Winding damage can be avoided by simply using Class F or H insulation on the windings. This is now standard on most new motors. But as for electrical bearing damage, bearing protection is not yet standard on all new motors.
The best way to protect motor bearings from electrical damage is to install an AEGIS® Shaft Grounding Ring. (Motors over 100 hp also require one insulated bearing.) AEGIS Rings can be installed in the field or in repair shops, outside or inside the motor. They are the only shaft grounding component that can be installed on Class 1/Div 1 explosion proof motors.
AEGIS Rings are also the only electrical bearing protection to offer a two-year extended warranty against electrical bearing damage. The warranty applies to new and repaired motors, as well as to motors with AEGIS factory-installed.
A large and growing number of motor manufacturers offer motors with AEGIS Rings. AEGIS Rings come standard in hundreds of motors made by ABB (Baldor), WEG, Nidec, Marathon, and several others. See IndustrialMatrix for a searchable database of motors with AEGIS factory-installed.
AEGIS Rings also come with a 2-year extended warranty against bearing fluting damage. No other form of protection against VFD-caused bearing damage offers a warranty like this.
To learn more about AEGIS shaft grounding and best practices for electrical bearing protection, sign up for a training. We offer monthly live training webinars, and - pandemic restrictions permitting - we can also visit your facility to review your exact application.
