SEW-EURODIVE: Maximizing Gearmotor Speed Range

November 2, 2018

Maximizing Gearmotor Speed Range is SEW-EURODRIVE’S technical white paper that shows how to operate VFDs above 60Hz to widen gearmotor speed range, improve system stability, and reduce cost. In fact, operating VFDs as high as 120Hz may significantly enhance gearmotor performance.

Many engineers assume that the inverter and gearmotor must operate within the 60Hz threshold. Some think that going to a high speed above 60Hz may cause the motor to overheat. But in reality, stopping at 60Hz may actually cause the motor to overheat at a low speed.

With a carefully designed drive system and correct ratio, pushing the operating frequency above 60Hz is possible using one of two proven control methods – field weakening or supercharging. Both methods are discussed in detail, along with technical charts and formulas. Through a common conveying example, the paper demonstrates how to properly select a gearmotor that will significantly enhance performance in the following ways:

• Increase stability by reducing inertia mismatch

• Widen the available speed range

• Eliminate a costly ventilator fan at low speed

• Eliminate motor overheating at low speed

• Enable the use of a smaller motor

Visit www.sewwhitepapers.com/vfd to download the PDF.