Ever since motors were clearly identified as the major source of energy use in industrial facilities, which also happen to be the largest users of energy, the race has been on by motor suppliers to deliver ever more efficient motor designs. You can read more about this trend in the Automation World article “Energy Efficiency: The Secret to Sustainable Machines.”
One of the newest entries into the energy-efficient motor area is the L-Force three-phase MF Motor from Lenze Americas. Designed to operate with a frequency inverter, this new motor can reportedly deliver the same rated power as a conventional asynchronous motor, yet be up to two sizes smaller.
“The MF Motor features a wide speed setting range of 1:24, about twice as fast as conventional motors. Due to the higher rotational speed of the MF motors, a size 71 device, for example, is sufficient for a rated power of 1.5 kW that would otherwise require a size 90 conventional three-phase motor,” explains Wayne Lazzerini, mechanical product manager, Lenze Americas.
Available in power ranges from 0.55 to 22 kW, MF three-phase AC motors are said to deliver efficiency levels of 94 to 98 percent due to the motor’s right-angle and in-line gearboxes which reportedly ensure that energy output by the motor is transferred to the application with minimal losses. A correspondingly higher gearbox ratio is used to compensate for the improved motor speed.
Lazzerini says Lenze’s MF Motors are compatible with either a central control cabinet drive or a decentralized motor inverter. Lenze recommends combining the MF motor with an 8400 series inverter, which comes equipped with an energy saving VFCeco (Voltage Frequency Control Economic) function. VFCeco automatically adapts the magnetizing current of the MF Motor to the operating conditions, increasing efficiency during partial load and reducing energy use by up to 30 percent.