Features: Heavy duty frames Ball bearings Moisture resistant ISR® (Inverter Spike Resistant) copper windings Low-loss electrical lamination grade steel Typical Applications: Typical applications include operations where continuous or frequent duty is required. Super-E Motors are designed to conserve energy over extended time periods. Inverter rated per NEMA MG1 Part 31.4.4.2. Suitable for variable torque applications and 20:1 constant torque speed range with properly sized and adjusted variable frequency drives.