MF motors are at least one frame size smaller

The new and innovative MF three phase motors from Lenze are designed for optimum performance with frequency inverters. Increased power means that MF motors can be up to two frame sizes smaller than conventional asynchronous motors with the same rated power. Over a power range from 0.55 to 22kW, MF motors deliver efficiency levels better than IE2 and they take away worries about compliance with the ErP regulations. The higher rated speeds of the MF motors, around 3400 to 3500r/min according to size, leads to higher power ratings. A frame size 71 is sufficient for 1.5 kW where a conventional three phase 4 pole motor would be 90 frame, resulting in smaller drive footprints. Another advantage is the speed setting range where constant torque is available is 1:24, about twice as good as the alternative. Furthermore the higher speeds lead to increased efficiency, contributing to the efficiency figures better than IE2 levels. In many cases the MF motors are supplied as part of a geared motor assembly. Usage is increasing in areas such as retrieval and storage units, and machine feeds where the smaller sizes and lower inertias permit more dynamic operation. Lenze offer a range of in-line and right angle gearboxes with correspondingly higher ratios to compensate for the increased motor speed. In most cases the reduction is possible without an additional gearbox stage as the input pinion is a part of the motor shaft, achieving high ratios in small dimensions. The MF motor range is perfectly matched by the Lenze 8400 series frequency inverters. These are available for both central panel mounting and decentralised control with an IP65 protected variant. This second option can be mounted in the motor terminal box position or on a wall nearby. Particularly in applications with partial loads, new VFCeco software which is standard with the 8400 inverters can give further energy savings of up to 30%. The new MF motors offer significant savings compared to standard 4 pole motors in a power range 0.55 to 22kW. Their smaller size helps machine construction and gives a more dynamic performance. They are energy efficient and the savings can be enhanced by VFCeco software in the matching 8400 inverter range. In many cases they are actually lower in cost than a 4 pole standard motor of the same power. Details and catalogue downloads are available on the Lenze website.