Lenze's new international sales structure

Left: drive package with GKR
geared motor.
Lenze closes the gap
With its MF L-force three-phase AC motors specially
optimised for frequency inverter operation, Lenze has
demonstrated for the first time what these motors are
really capable of. Their compactness, dynamic performance,
variability and efficiency are all impressive.
The new MF motors are up to two frame sizes smaller
than a traditional three-phase AC motor of the same
power. In frame size 71, for example, they have a rated
power of 1.5 kW. It would take a normal three-phase AC
motor in frame size 90 to deliver the same power. The
lower axis height results in a reduced moment of inertia
compared to a motor optimised for mains operation. The
dynamic performance of the MF L-force three-phase AC
motor puts it between a servo motor and a normal threephase
AC motor.
The setting range of the L-force three-phase AC motor is
about 1 : 24 (without field weakening). Hence the motor
is similar to a servo motor in that it can be used at highly
variable speeds.
The MF three-phase AC motors exceed the minimum
efficiency standards for efficiency class IE2. The lower
moment of inertia as compared to standard motors further
reduces energy consumption when speeds are varied.
To realise all these advantages, Lenze put to further good
use the extensive, perfectly fitting building blocks familiar
from its MD/MH L-force three-phase AC motors, such
as motor feedback systems, surface and corrosion protection
packages, and a wide range of spring-applied brakes.
As compared to many servo motors, the spring-applied
brakes offer a further advantage when maintenance work
is required: while the permanent magnetic brakes used
in servo motors often serve merely as holding brakes, the
spring-applied brakes in the new L-force three-phase AC
motors are easily accessible, can be readjusted repeatedly,
and can be used also as service brakes, for example
in storage and retrieval units.
Even better in a drive package
To realise the advantages of the optimised three-phase
AC motors in complete drive systems, Lenze has put
together a package that offers the new 8400 motec
motor inverter and the L-force gearbox along with the
motors. The distributed frequency inverter mounted on
the motor and the integrated right-angle or coaxial
gearbox lead to compactness.
The entire drive package also stands out by virtue of the
high energy efficiency of all of its components. In addition
to the high efficiency of both gearbox and motor, the
8400 motec frequency inverter offers intelligent adjust-
ment of the magnetising current in VFCeco mode. In
partial load operation in particular, three-phase AC motors
have always been supplied with a higher magnetising
current than operating conditions required. By contrast,
VFCeco operation adjusts the magnetisation of the load,
thereby reducing energy consumption by up to 30 %.
20 % lower acquisition costs
The MF L-force three-phase AC motors are the first to
exploit the potential of using frequency inverters. As
compared to normal three-phase AC motors, the result is
a substantial performance increase, including high energy
efficiency and a compactness and dynamic performance
similar to those associated with servo motors. The 8400
motec distributed frequency inverters and the L-force
gearbox, which form the ideal drive package in combination
with the motor, help achieve these advantages.
The real main attraction, however, is the purchase cost.
As compared to a 50 Hz three-phase AC motor of equal
power (the most reasonable solution in terms of cost to
date), the price has been lowered by more than 20 %. A
pay-back analysis of the type used in the case of highlyhigh
efficiency motors is no longer necessary.
teChnologY
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