US Motors is a leader in the vertical hollow shaft motor market. Their HOLLOSHAFT® Motors are ideal for use on turbine, mix flow, propeller, and other pumps. And now, all of their Inverter Duty Weather Protected Type I (WPI) and CORRO-DUTY® HOLLOSHAFT motors include AEGIS® Shaft Grounding Rings for electrical bearing protection.
WPI HOLLOSHAFT motors are constructed to minimize ingress of rain and snow, as well as dust and dirt. And their ventilation system optimizes cooling of the thrust bearing and electrical components. CORRO-DUTY motors have TEFC frames to prevent ingress and corrosion-resistant paint and hardware for extremely harsh environments.
Inverter duty motors are designed to resist the side effects of variable frequency drive (VFD) control. VFDs can cause electrical damage to both the stator windings and the bearings of the motors they control. To protect the windings, these inverter duty motors include Class H Inverter Grade® insulation.
VFDs produce voltage on the shafts of the motors they control, and this voltage can cause arcing through the bearings. In larger motors, over 100 hp, drives also produce high-frequency circulating currents that go through both bearings at once. All inverter duty WPI and CORRO-DUTY HOLLOSHAFT motors include an AEGIS Shaft Grounding Ring mounted inside, to discharge shaft voltage safely. And those over 100 hp also include an insulated thrust bearing to block circulating currents.
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 we can also visit your facility to review your exact application.
