Product Overview

The Emerson DST1403 Digitax ST Servo Drive is a three-phase AC servo drive in the Digitax ST family, used to control compatible servo motors in industrial motion systems. With a rated output current of 4.0 A and a peak output current of 12.0 A, it occupies a higher current class than the DST1401 and DST1402, making motor-current requirements an important factor when selecting this model.

The drive operates from a 380–480 V AC supply and is intended for applications that require controlled acceleration, deceleration and coordinated motor movement. Typical examples include packaging machines, material indexing systems, automated assembly equipment and servo-driven transfer mechanisms.

In a machine with repeated start-stop movements, the motor may need substantial current during acceleration and deceleration even when its average operating load is lower. The DST1403’s rated and peak current capabilities must therefore be evaluated against the motor’s electrical data, mechanical inertia and required duty cycle. A drive that meets the continuous current requirement may still be unsuitable if the application’s short-duration current demand exceeds its permitted peak rating.

The DST1403 uses the Digitax ST Frame Size 1 configuration. When replacing an existing drive, engineers should confirm the complete model number, supply voltage, feedback interface and control configuration rather than relying on the physical mounting arrangement alone.

Technical Specifications

Product Features

• Three-phase AC supply: Operates from the specified 380–480 V AC supply class.
• 4.0 A rated output current: Supports compatible motors requiring a higher continuous current than the DST1401 or DST1402.
• 12.0 A peak output current: Accommodates short-duration current demand within the drive’s permitted operating limits.
• Digitax ST platform: Fits into compatible servo control architectures using the same drive family.
• Closed-loop motor control: Uses supported feedback equipment to regulate motor movement.
• Internal fan cooling: Removes heat generated during operation through the drive’s cooling arrangement.
• Configurable control parameters: Allows motor data, current limits and control settings to be matched to the application.
• Optional interface support: The Digitax ST family offers additional interface and control options, subject to the specific drive variant and configuration.

Working Principle

The DST1403 converts incoming three-phase AC power into controlled electrical output for a compatible servo motor. The drive regulates motor current according to the selected control mode and the commands supplied by the machine’s motion controller.

When an axis accelerates, the drive increases motor current to generate the torque needed to overcome inertia and mechanical resistance. As the motor approaches its target speed or position, the control loop adjusts the output to follow the requested motion profile. During deceleration, the drive manages the motor response and any regenerative energy according to the configured braking arrangement.

Consider an automated assembly station that moves a workpiece into a positioning fixture. The servo axis must accelerate quickly, reach the required position and settle before the next operation begins. The DST1403 controls the motor response, while the controller determines the movement sequence and coordinates the axis with the rest of the machine.

The 12.0 A peak rating is not a continuous operating rating. Current demand, overload duration, switching frequency, ambient temperature and the required motion profile all affect the usable drive capacity. Correct motor data and feedback configuration are also essential for predictable operation.

Role in a Digitax ST Servo Motion Control System

The DST1403 serves as the electrical power-control stage between the AC supply and the servo motor. It receives motion commands, regulates motor output and processes compatible feedback signals as part of the configured servo control loop.

Three-Phase AC Supply → DST1403 Servo Drive → Servo Motor → Mechanical Axis

Motion Controller → Command Interface → DST1403 → Motor Feedback and Control Loop

Industrial Applications

Installation and Maintenance

1. Verify the drive reference: Confirm that DST1403 matches the required voltage class, current rating and control configuration.
2. Check the incoming supply: Verify that the available three-phase AC supply falls within the specified 380–480 V range.
3. Match the motor rating: Compare the motor’s continuous and peak current requirements with the drive’s ratings and permitted overload characteristics.
4. Isolate the equipment: Follow the approved electrical isolation procedure and allow the specified DC-bus discharge time before handling the drive.
5. Inspect cabinet ventilation: Ensure that the internal fan has adequate airflow and that the mounting arrangement meets the installation requirements.
6. Examine the power terminals: Check the incoming supply, motor output and protective earth connections for damage or loose terminations.
7. Verify feedback wiring: Confirm that the motor feedback device, cable and drive interface are compatible.
8. Check motor parameters: Verify the motor data, control mode, current limits and relevant feedback settings before enabling the drive.
9. Review braking requirements: Determine whether the application’s inertia and stopping cycle require a braking resistor or another approved energy-management arrangement.
10. Inspect control wiring: Check command signals, enable circuits, interlocks and installed option modules.
11. Commission the axis: Test rotation direction, feedback response, acceleration, deceleration and positioning under controlled conditions.
12. Record service information: Document the drive reference, motor configuration, parameter settings, fault history and commissioning results.

Compatible System Components

Recommended Related Models

Key Advantages

• Operates from a three-phase 380–480 V AC supply.
• Provides 4.0 A rated output current and 12.0 A peak output current.
• Supports servo motion control with compatible motor feedback.
• Uses internal fan cooling.
• Fits suitable installations using the Digitax ST Frame Size 1 configuration.

Technical FAQs

How does the DST1403 differ from the DST1402?

The DST1403 has a rated output current of 4.0 A and a peak rating of 12.0 A, compared with 2.7 A and 8.1 A for the DST1402. The correct choice depends on motor current demand, acceleration requirements and application duty.

Can the DST1403 supply 12.0 A continuously?

No. The 12.0 A figure is the peak output current rating. Continuous operation must remain within the drive’s rated current and applicable thermal limits.

What should be checked if the drive trips during rapid acceleration?

Review the motor current demand, acceleration settings, mechanical inertia, feedback configuration and recorded fault information. Confirm that the motor and drive ratings match the required motion profile before changing current limits.

Does the DST1403 require a braking resistor?

Not every application requires one. The need depends on regenerative energy, load inertia, deceleration frequency and the drive’s permitted energy-handling arrangement. The braking system must be selected for the actual operating cycle.