Rockwell Automation FlexPak 3000 DC Drive Version 4.3 User Manual
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FlexPak 3000 DC Drive Hardware Reference Version 4.3
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 lb. ft. squared, oz. in.
squared, or mkg squared.
LCD: Liquid Crystal Display.
LED: Light Emitting Diode.
motor: A device that converts electrical energy to mechanical energy to turn a shaft.
motor electrical time constant: The ratio of electrical inductance to armature
resistance. Electrical time constant in seconds defined as:
T/C = La x Ia / Hot IR voltage drop
motor identification:
•
Frame designation (actual frame size in which the motor is built)
•
Horsepower, speed, design and enclosure
•
Voltage, frequency and number of phases of power supply
•
Class of insulation and time rating
•
Application
motor nameplate: The plate on the outside of a motor which describes the motor, HP,
voltage, RPM, efficiency, design, enclosure, etc.
motor thermostat: Unit applied directly to the motor's windings which senses winding
temperature and may automatically break the circuit in an overheating situation.
non-retentive: Information and/or data not retained while power to the drive is OFF.
power (P) in kW: The measure of the rate of work. One kilowatt (kW) is equivalent to
lifting 98 kg to a height of one meter in one second. 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
RPM = revolutions per minute
retentive: Information and/or data retained while power to the drive is OFF.
RPM: Revolutions per Minute - The number of times per minute the shaft of the motor
(machine) rotates.
Inertia reflected to the shaft of the motor
load inertia
load RPM
motor RPM
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