ABB
130
ABB/ BU Machines / HV Induction motors IEC catalogue / Motors for variable speed drives EN 12-2007
3
General Information
The voltage (or current) fed by the frequency converter
is not purely sinusoidal. This may increase any losses,
vibration and the noise of the motor. The engineered
motors described in this section are specifically
designed for supply through a frequency converter.
The design can be varied according to the customer's
specifications including altering the speed range for
continuous operation and operating with short-time
overload. ABB design considers the different types of
variable speed drive available depending upon their
electromagnetic design. The rating for motors designed
for converter supply differs from that of the direct-on-
line (DOL) motors.
In addition to the standard information given on the
rating plates there is additional information that relates
to frequency converter driven machines. An example of
the rating plate is shown on page 132.
All the motors described in this catalog come with
the form wound winding Micadur
®
Compact Industry
Insulation system, similar to that used in the high
voltage motors. This construction yields very moderate
voltage stresses between the winding elements
even when supplied with the most efficient inverter
types and the steepest voltage pulses. This makes
installation easier and results in lower losses and better
performance for the entire drive system as no chokes or
filters are needed.
Bearing voltages and currents must be avoided in all
motors and all ABB large motors for low voltage variable
speed drives are equipped with bearing insulation in
non-drive end. Please contact ABB for more information
about bearing currents and voltages.
AC machines supplied from a frequency converter must
be fitted with screened cables to comply with the EMC
directive (89/336/EEC, as amended by 93/68/EEC).
Please see ABB's 'Manual for Induction Motors and
Generators' (code: 3BFP 000 050 R0101) or contact us
for more information about EMC compliance.
Examples of different load types
Variable Torque (pumps, fans, etc.)
The table below shows the electrical rating plate
values for rated power, voltage, current, power factor,
frequency and speed of a pump drive. The load torque
is assumed to be quadratic (as function of speed), and
the motor can be operated continuously over the entire
speed range. The field weakening point is 42.7 Hz.
CONVERTER SUPPLY
S1
0
-
1200
kW
0
-
660
V
0 - 42.7
Hz
0 - 1360
A
0 - 850
rpm
0 - 0.79
PF
Table above: Rating plate values for a pump drive.
0
0.5
1
0
1
speed
Figure above: Load torque curve for a pump drive.
This section describes ABB's engineered motors
for low voltage variable speed drives. The basic
mechanical construction is the same as described in
Section 2. This section includes drawings showing the
low voltage main terminal box.