Rockwell Automation SA3100 AutoMax Distributed Power System - Manual (Page 45)

Glossary A-1
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PPENDIX
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Glossary
AC contactor: a contactor designed for the specific purpose of establishing and
interrupting an AC power circuit.
AC current: current that reverses direction of flow at regular intervals; the measure of
the intervals is the frequency (60Hz in US, 50Hz in Europe); available in single phase
and three-phase.
AC motor: a motor designed to operate on alternating current; there are two primary
types, induction and synchronous.
A/D converter: Analog to Digital converter; a circuit which converts an analog voltage
or current to a digital word (series of bits).
adaptive gain: in DC drives, this is a function of the CML. When a drive is in
discontinuous conduction, there are periods of low current demand; the SCRs (silicon
controlled rectifiers) provide pulses of current instead of continuously flowing current
for the armature. Adaptive gain changes the gains based on feedback signals from the
Power Module. This allows the drive to maintain optimum control of armature current
when current demand is low.
adjustable speed control: the ability to control the operating speed of a motor within
a predetermined range.
ambient temperature: the temperature of the air in the area where equipment is
stored or operated.
amplitude: the magnitude of a signal or waveform, usually measured zero-to-peak,
peak-to-peak, or RMS.
anti-parallel: for Reliance drives, this term defines the configuration of a DC drive
Power Module that allows both motoring and regeneration. Also referred to as back-to-
back converter configuration.
application task: see task.
armature (motors): the rotating, current-carrying part of a DC motor.
armature control: varying the speed of a DC motor (0 to motor base speed) by
varying the amount of DC voltage applied to the armature; also called armature
voltage control.
armature current: the flow of electrons through the armature windings of a DC motor
which produces torque to turn a load.
armature inductance: the inductance of the motor armature circuit in millihenries.