Rockwell Automation FlexPak 3000 Power Module Version 4.2 - Manual (Page 103)

APPENDIX A
49’1340 e FlexPak 3000 A-1
Glossary of Terms
Altitude: The atmospheric altitude (height above sea level) at which the motor or drive will be operating.
Armature: The portion of the DC motor that rotates.
Armature Resistance: Measured in ohms at 25 degrees Celsius (cold).
Base Speed: The speed which a DC motor develops at rated armature voltage and rated field current
with rated load applied. Typically nameplate data.
Constant Speed: Used to describe a motor which changes speed only slightly from a no-load to a full-
load condition.
DC Motor: A motor using either generated or rectified DC power.
A D-C motor is usually used when variable speed operation is required.
DB: Dynamic Braking
Default Value: Parameter values which are stored in the drive's Read Only Memory (ROM).
Direct Current: A current that flows only in one direction in an electrical circuit. It may be continuous or
discontinuous and it may be constant or varying.
Drive: Power converting equipment supplying electrical power to a motor.
Efficiency: The ratio of mechanical output to electrical input. It represents the effectiveness with which the
motor converts electrical energy to mechanical energy.
Field: A term commonly used to describe the stationary (stator) member of a DC motor. The field provides the
magnetic field with which the mechanically rotating (armature or rotor) member interacts.
Power P in kW: The measure of the rate of work. The kW rating of a motor is expressed as a function of
torque and RPM.
For motors, the following approximate formula may be used:
P = M x RPM / 9550
where,
M = Torque in Nm and
RPM = revolutions per minute.
Inertial Load: A load (flywheel, fan, etc.) which tends to cause the motor shaft to continue to rotate after
the power has been removed (stored kinetic energy). If this continued rotation cannot be tolerated, some
mechanical or electrical braking means must be applied. This application may require a special motor due
to the energy required to accelerate the inertia. Inertia is measured in kg m 2 .
Inertia reflected to the shaft of the motor = load Inertia
load RPM
motor RPM
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LCD: Liquid Crystal Display.
LED: Light Emitted Diode.