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The Emerson SP2403 Unidrive SP Series AC Drive is a universal AC and servo drive for industrial machinery requiring variable-speed operation, configurable torque response and integration with automated control systems. Its Size 2 platform supports applications with higher motor-current requirements than the SP1400 models, including production equipment that must maintain controlled motor behavior as process loads change.
For the 380–480 V three-phase model, the SP2403 is rated at 25 A Heavy Duty output current and 29 A Normal Duty output current under the applicable rating conditions. It supports several motor-control approaches, including open-loop vector control, V/Hz control, rotor flux control, closed-loop induction motor control and compatible servo operation. The appropriate configuration depends on the motor, required control performance and application.
In a machine-control system, the SP2403 receives operating commands and speed or torque references, then regulates motor output according to its configured parameters. Its onboard Modbus RTU interface supports communication with compatible automation equipment, while optional modules can add network, feedback or application-specific functions. These capabilities make commissioning settings, process coordination and fault diagnosis important parts of configuring the drive for a specific machine.
| Parameter | Specification |
|---|---|
| Manufacturer | Emerson / Control Techniques |
| Model | SP2403 |
| Product Series | Unidrive SP |
| Product Type | Universal AC and Servo Drive |
| Frame Size | Size 2 |
| Input Supply | Three-phase AC |
| Input Voltage | 380–480 V AC |
| Input Frequency | 48–65 Hz |
| Heavy Duty Continuous Output Current | 25 A |
| Normal Duty Continuous Output Current | 29 A |
| Typical Motor Power at 400 V, Heavy Duty | 11 kW |
| Typical Motor Power at 400 V, Normal Duty | 15 kW |
| Motor Control Modes | Open-loop V/Hz, open-loop vector, rotor flux control, closed-loop induction motor control and compatible servo control |
| Analog Inputs | 3 |
| Analog Outputs | 2 |
| Digital Inputs | 7 |
| Digital Outputs | 3 |
| Relay Outputs | 1 |
| Onboard Communication | Modbus RTU |
| Option Slots | 3 |
| Feedback Expansion | Compatible feedback option modules |
| Enclosure Protection | IP20 for the panel-mount version |
| Dimensions | 368 × 155 × 219 mm |
| Weight | 2 kg |
The SP2403 converts three-phase AC input power into a controlled electrical output for the connected motor. Its power electronics regulate the output according to the selected control mode, programmed motor data and active reference commands. Depending on the application, the drive can operate with open-loop control or use a compatible feedback arrangement for closed-loop operation.
The model’s output-current rating is 25 A in Heavy Duty operation and 29 A in Normal Duty operation. These ratings apply under their respective operating conditions, and the appropriate duty must be selected according to motor current, overload requirements and load behavior. The actual operating environment and switching-frequency configuration can also affect the permissible continuous current.
Control references and programmed ramp settings determine how the motor responds to changes in demand. On equipment with high inertia, frequent stopping or rapid speed changes, the deceleration strategy and braking arrangement need to be assessed together. In feedback-based applications, the feedback device and its configuration must also match the selected control mode.
When the drive trips, the recorded fault and operating conditions provide the starting point for diagnosis. Checking supply stability, motor connections, control references, feedback signals and load conditions can help isolate the cause before any parameter changes are made.
The SP2403 functions as the motor-control layer between the electrical supply, machine controller and driven equipment. It executes the configured control strategy, regulates motor output and returns supported operating information for supervision and fault handling.
| System Component | Function | Relationship to the Drive |
|---|---|---|
| Three-Phase AC Supply | Supplies electrical input power | Feeds the drive through appropriately rated isolation and protective devices |
| AC Induction Motor | Converts electrical power into mechanical motion | Receives the drive’s controlled output |
| Compatible Servo Motor | Provides controlled motion in supported applications | Requires a suitable control mode and compatible configuration |
| PLC or Machine Controller | Coordinates machine sequencing | Sends compatible run commands, references and enable signals |
| Analog Reference Source | Supplies a variable speed or process reference | Connects to a configured compatible analog input |
| Digital Control Circuit | Carries run, stop and interlock signals | Uses the drive’s supported digital I/O |
| Modbus RTU Master | Exchanges supported drive data | Communicates through the onboard serial interface |
| Encoder or Feedback Device | Supplies speed or position information where required | Requires a compatible feedback interface and supported control mode |
| Braking Arrangement | Manages regenerated energy during applicable stopping cycles | Must be selected according to the load and drive configuration |
| Supervisory System | Displays operating status and diagnostic information | Uses supported communication or controller-mapped signals |
| Application | Operating Requirement | Role of the SP2403 |
|---|---|---|
| Industrial Conveyor Lines | Coordinate speed with material flow and production timing | Regulates motor speed through configured references and operating limits |
| Extrusion and Material Processing | Maintain motor response as process loads change | Applies configured control parameters and current limits |
| Pumps and Fluid Handling Systems | Adjust motor operation to changing process demand | Supports variable-speed control when the motor and pump are appropriately matched |
| Fans and Blowers | Adjust airflow through motor-speed control | Changes motor speed in response to the required reference |
| Winding and Unwinding Equipment | Coordinate motor speed or torque with line conditions | Supports suitable configured speed or torque-control strategies |
| Packaging Machinery | Match motor response to machine-cycle timing | Executes programmed speed and ramp settings |
| Cutting and Processing Machines | Coordinate motor operation with production commands | Provides configurable motor control within the drive’s ratings |
| General Industrial Machinery | Integrate motor operation with automation logic | Processes compatible commands and supplies status and fault information |
| Component | Function | Compatibility Consideration |
|---|---|---|
| Compatible AC Induction Motor | Produces mechanical output | Verify voltage, rated current and control requirements against the drive |
| Supported Servo Motor | Provides controlled motion in suitable applications | Confirm the required control mode and motor compatibility |
| PLC or Machine Controller | Coordinates machine logic | Confirm supported command signals and interface arrangements |
| Analog Reference Source | Supplies a speed or process reference | Match signal type and scaling to the configured input |
| Encoder or Feedback Device | Provides speed or position information | Requires a compatible feedback option and supported device |
| Modbus RTU Master | Exchanges supported drive information | Configure serial settings and supported data mapping |
| Communication Option Module | Adds a supported network interface | Verify the exact module and protocol compatibility |
| Braking Components | Support applicable deceleration requirements | Select according to the load and drive configuration |
| Upstream Protective Device | Protects the input supply circuit | Select according to the electrical installation design |
| Model | Product Type | Relationship | Selection Consideration |
|---|---|---|---|
| Emerson SP1406 | Unidrive SP AC Drive | Smaller-frame model with lower current capacity | Compare its output-current ratings with the motor’s requirements |
| Emerson SP2401 | Unidrive SP AC Drive | Lower-current model in the same frame group | Check whether its 13 A Heavy Duty and 15.3 A Normal Duty ratings are sufficient |
| Emerson SP2402 | Unidrive SP AC Drive | Lower-current model in the same frame group | Compare its 16.5 A Heavy Duty and 21 A Normal Duty ratings with the load |
| Emerson SP3401 | Unidrive SP AC Drive | Related model from a larger frame group | Evaluate the required current capacity, mounting arrangement and installation conditions |
Choose a control mode suited to the motor and torque requirement, then verify motor data and operating limits. If the application requires closed-loop performance, confirm that the feedback device and interface are compatible and correctly configured before tuning the control response.
Review the actual output current, selected duty rating, ambient temperature, switching-frequency configuration and panel ventilation. Also check for sustained overload or an unsuitable motor application before changing operating parameters.
Where the required functionality is supported by the installed configuration, drive-resident logic can handle selected control tasks locally. Confirm the available programming functions, I/O assignments and interaction with the main PLC, then test interlocks and fault behavior before commissioning.
Check feedback wiring, signal quality, encoder configuration, the selected feedback interface and the programmed motor data. Also inspect the mechanical coupling and verify that the feedback device is appropriate for the speed range and operating conditions.