Nidec's U.S. Motors is one of the oldest and most respected brands of electric motor. They may be best known for their specialty motors, like vertical HOLLOSHAFT®, Vari-Tough® condenser motors, and the severe duty World Motor® family. But U.S. Motors also makes general purpose motors, like their Unimount® line.
Unimount motors come with a wide range of electrical and mechanical features. They can power pumps, fans, and compressors, by belt or direct drive, or direct connection. And they are well-protected against external and internal sources of damage. They come with a Class F Inverter Grade® insulation system to protect against winding damage from VFD power.
Their bearings are well-protected, too. Unimount motors from 56 to 140 frame have sealed bearings, and from 180 up, they have double shielded bearings. This protects the bearings from contamination from outside. And now, all Inverter Duty Unimount motors over 140 frame are protected against electrical damage by an AEGIS® Shaft Grounding Ring.
A VFD creates voltage on the motor shaft. This voltage can discharge by arcing through the bearings, causing electrical beairng damage. AEGIS Rings create a low-resistance path from the motor shaft to the frame. So rather than building up and then arcing through the bearings, charge drains harmlessly through the ring.
With protection against both external and internal sources of damage, the bearings in Inverter Duty Unimount motors are highly unlikely to fail prematurely. Bearing failure is the largest single cause of motor failure. So that means you can expect a Unimount motor to run reliably for years and years.
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.
