The Marathon® Motors brand began with a single washing machine motor and a simple ambition: To produce the most efficient and longest-lasting motors. A lot has changed since 1913, but the goal remains the same. Marathon, and its parent company Regal Beloit, still provide high-quality ultra-efficient motors, but now with more advanced technology and for hundreds of industries.
One relatively new development in the motor arena is control by variable frequency drives (VFDs). These drives are used in all sorts of applications because they offer precise control and often large energy savings as well. But these benefits come at a price: VFDs' pulsed output can burn through the insulation on motor stator windings, and can also cause electrical discharge through, and damage to, the bearings. Both of these can cause the motor to fail prematurely.
But Marathon is up to these new challenges. Like all major motor manufacturers, they offer "inverter duty" motors with Class F or H insulation to resist sudden changes and spikes in the voltage supply. Several lines include their patented MAX GUARD® insulation. And as for bearing damage, Marathon offers several lines of motors with Bearing Current Protection ("BCP") in the form of AEGIS® Shaft Grounding Rings. These BCP motors, with protection against electrical damage to the windings and bearings, can truly be called "inverter duty."
BCP (as an AEGIS Ring) is included in all Marathon Blue Max® 2000 vector-duty motors and Blue Chip® Severe Duty cooling tower motors. BCP is also included in all motors whose part numbers end with "-P" in general-purpose NEMA Premium® XRI® Efficiency motors and Hazardous Duty™ Blue Chip Severe Duty motors.
For the part numbers of all stock Marathon Motors with BCP, see this brochure. BCP can also be added as a mod to any Marathon motor. Also, all motors with AEGIS Rings factory installed are eligible for the AEGIS 2-year extended warranty against electrical bearing damage.