Rockwell Automation 1391 USER MNL/DIGITAL AC SERVO DR - Manual (Page 6)

Chapter 1
Introduction
1-7
The 1391-DES is generally used with computer aided, closed loop
positioning systems such as Allen-Bradley “S” Class or IMC products.
These systems control the position and linear or rotary motion of various
machine members on an automated machine. To enhance system reliability,
the 1391-DES has an encoder output (AQB) that produces four channels of
2048, 1024, 512 or 256 lines and two marker pulses per motor revolution
which feeds position information to the position controller.
All components are mounted in an open framed package with a slide-on
front cover. The drive is intended to be panel mounted in an enclosure and
ventilated with filtered and/or cooled air. An internal fan is included to
circulate air over the power heat sink.
The 1391-DES converts a three-phase, 50/60 Hz input, to a variable AC
voltage with controlled phase, amplitude and frequency. The output which
is proportional to a user supplied analog command, regulates the speed
and/or current (torque) of a 1326 permanent magnet AC servomotor. The
drive is available in ratings of 15, 22.5 and 45A RMS with all package
sizes being identical. A 1391 Transformer, 1326 AC Servomotor and 1326
Cables complete the servo system.
Standard Features The 1391-DES contains a number of standard features required in a typical
automated machine servo system.
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Input protected against transient voltage.
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A power line/DB contactor which opens the AC line to the drive and
inserts a shunt regulator resistor across the DC bus whenever the
contactor is de-energized.
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An integral circuit breaker which will open all three AC line leads in the
event of a short circuit condition in the power circuitry.
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A standard 300V DC power bus supply that includes an integral shunt
regulator.
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A shunt regulator resistor to dissipate the energy generated by the motor
during regenerative braking.
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Prompted startup procedure to shorten setup time.
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Two line LCD display and programming panel.
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Patented current control implementation.
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Torque feedforward differential input.
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Microprocessor based logic boards that can be quickly removed and
easily interchanged for troubleshooting and diagnostics.
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Three drive ratings that are in the same physical package and have
identical mounting dimensions.
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True vector control.
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Up to 600 feet (183 meters) between drive and motor.