Our advantage
Global Logistics
We have a 10-year logistics and express cooperation agreement, so our products can be shipped to any place in the world.
Brand new and original
Our products are imported in bulk from the place of origin. Because of the cooperative relationship, our products are all original and 100% new.
24-hour service
We provide 7*24 hours service to our customers. We will be there whenever you need us.
Price advantage
All our products are priced very favorably because we have our own warehouse and supply.
| Company Information | |||
| [email protected] | |||
| Mobile | +8615980777398 | ||
| +8615980777398 | |||
| 15980777398 |

The Emerson SP3402 is a high-performance variable-speed drive in the Unidrive SP series from Control Techniques. It is used to regulate AC motor speed and torque in industrial machinery, supporting applications that require adjustable operating speeds, controlled acceleration and deceleration, and integration with machine automation systems.
The SP3402 operates from a three-phase 380–480 V AC supply. It is rated for 18.5 kW in Heavy Duty operation and 22 kW in Normal Duty operation, with corresponding output current ratings of 40 A and 43 A. These ratings make it suitable for a range of industrial motor-control tasks, including conveyor systems, pumps, fans and material-processing equipment.
The drive supports multiple control modes, including open-loop V/Hz, open-loop vector, rotor flux control, closed-loop vector and compatible servo operation. Built-in RS-485 communication, configurable I/O, three option-module slots and an integrated drive PLC function allow the SP3402 to be adapted to different machine-control architectures. Its Smartcard functionality also supports the storage and transfer of compatible drive parameters and programs.
| Parameter | Specification |
|---|---|
| Manufacturer | Emerson / Control Techniques |
| Model | SP3402 |
| Product Series | Unidrive SP |
| Product Type | Universal AC and Servo Drive |
| Drive Configuration | Panel-Mount Variable-Speed Drive |
| Input Voltage | 380–480 V AC |
| Input Phase | Three-phase |
| Input Frequency | 48–65 Hz |
| Heavy Duty Output Power | 18.5 kW |
| Normal Duty Output Power | 22 kW |
| Heavy Duty Output Current | 40 A |
| Normal Duty Output Current | 43 A |
| Typical Motor Rating | 25 HP Heavy Duty / 30 HP Normal Duty |
| Control Modes | Open-loop V/Hz, open-loop vector, rotor flux control, closed-loop vector and compatible servo control |
| Serial Communication | Built-in RS-485, Modbus RTU |
| Analog Inputs | 3 |
| Analog Outputs | 2 |
| Digital Inputs | 7 |
| Digital Outputs | 3 |
| Relay Outputs | 1 |
| Expansion Slots | 3 option-module slots |
| Programmable Logic | Built-in drive PLC function |
| Enclosure Protection | IP20 |
| Cooling Method | Forced convection |
| Dimensions | 368 × 250 × 260 mm |
| Weight | 3.5 kg |
The SP3402 converts incoming three-phase AC power into a controlled electrical output for the connected motor. Its power electronics regulate output voltage and frequency according to the selected control mode, motor parameters and requested operating speed.
In open-loop V/Hz or vector operation, the drive adjusts the motor output according to the selected control strategy. Closed-loop vector operation uses compatible feedback equipment where required to improve speed and torque regulation. Servo applications require a suitable motor, feedback arrangement and configuration.
For example, on a material-handling line, a PLC can send a run command and speed reference to the SP3402. The drive accelerates the motor according to the configured ramp, maintains the requested operating speed and responds to stop commands or fault conditions. Status signals and communication data can be returned to the controller so that the wider automation system can coordinate the equipment.
The integrated PLC function supports local drive-related logic, while optional modules can add communication or feedback capabilities. Actual performance depends on motor characteristics, drive settings, feedback devices, switching frequency and the application load.
The SP3402 serves as the motor-power conversion and speed-control component in an industrial automation system. It receives operating commands and references from a controller or configured local logic, then regulates the electrical output supplied to the motor.
| System Component | Function | Relationship to the SP3402 |
|---|---|---|
| SP3402 AC Drive | Regulates motor voltage, frequency and operating behavior | Controls the connected motor |
| Three-Phase AC Supply | Supplies electrical power | Provides the drive input |
| Induction Motor | Converts electrical energy into mechanical motion | Receives the controlled drive output |
| PLC or Machine Controller | Executes machine sequencing and interlocks | Sends commands and speed references |
| Encoder or Feedback Device | Measures motor speed or position where required | Supplies feedback for supported closed-loop configurations |
| RS-485 Communication Network | Exchanges serial data | Connects the drive to compatible control equipment |
| Analog Reference Source | Provides a configured speed or process reference | Supplies a reference for drive regulation |
| Digital Control Signals | Carry run, stop, enable and other configured commands | Control drive operation |
| Braking Resistor | Dissipates braking energy where required | Supports applications requiring additional braking capability |
| Option Module | Adds supported communication, feedback, I/O or automation functions | Extends the drive configuration |
| Motor Protection and Isolation Devices | Support electrical protection and safe isolation | Form part of the surrounding installation |
The actual architecture depends on the motor type, selected control mode, feedback requirements and machine safety design.
| Application | Typical Equipment | Role of the SP3402 |
|---|---|---|
| Conveyor Systems | Production conveyors and material-transfer lines | Regulates motor speed to coordinate material movement |
| Pumping Systems | Industrial process and utility pumps | Adjusts motor speed according to process demand |
| Industrial Fans | Ventilation and process-air equipment | Controls airflow through variable-speed operation |
| Extrusion Machinery | Plastic and material-processing equipment | Regulates motor speed according to production requirements |
| Winding Equipment | Web handling and material winding systems | Supports configured speed and feedback control |
| Packaging Machinery | Automated packaging and conveying equipment | Coordinates motor speed with machine sequences |
| Material Handling | Industrial movement and lifting equipment | Supports motor regulation where drive and system ratings are suitable |
| Printing Machinery | Web-fed printing and material transport systems | Regulates motor operation within the configured control arrangement |
| General Manufacturing | Industrial machines with variable-speed motors | Provides adjustable speed and motor-control functions |
| Component | Function | Relationship to the SP3402 |
|---|---|---|
| Unidrive SP Keypad | Provides local parameter access and operating status | Supports local setup and monitoring when compatible |
| Smartcard | Stores supported drive parameters and programs | Assists with configuration transfer and backup |
| Encoder Feedback Module | Interfaces with compatible motor feedback devices | Supports applicable closed-loop control configurations |
| Communication Option Module | Adds supported industrial communication interfaces | Connects the drive to compatible automation networks |
| I/O Option Module | Adds supported input and output functions | Extends signal-handling capabilities |
| Braking Resistor | Dissipates braking energy where required | Supports applications with demanding deceleration requirements |
| Three-Phase Induction Motor | Converts drive output into mechanical motion | Serves as the controlled motor load |
| PLC | Coordinates machine logic and interlocks | Sends operating commands and receives status information |
| Motor Isolation Device | Provides electrical isolation for servicing | Supports safe maintenance procedures |
| Control Power Supply | Supplies associated control circuits where required | Supports the wider drive-control installation |
| Model | Product Type | Relationship | Selection Consideration |
|---|---|---|---|
| Emerson SP3402 | Unidrive SP Universal AC and Servo Drive | Main product | 380–480 V AC drive rated at 40 A Heavy Duty and 43 A Normal Duty |
| Emerson SP3401 | Unidrive SP Universal AC and Servo Drive | Lower-rated model in the same frame family | Compare output-current requirements and duty classification |
| Emerson SP3403 | Unidrive SP Universal AC and Servo Drive | Higher-current model in the same frame family | Evaluate the required motor current and operating conditions |
| Emerson SP2402 | Unidrive SP Universal AC and Servo Drive | Smaller frame family | Consider only where the required motor rating and installation arrangement permit |
| Emerson SP2403 | Unidrive SP Universal AC and Servo Drive | Smaller frame family | Compare current ratings, load requirements and control configuration |
Related models are not automatically interchangeable. Selection must account for supply voltage, motor current, duty rating, control mode, feedback requirements and installed option modules.
The SP3402 is rated at 43 A and 22 kW in Normal Duty operation, and 40 A and 18.5 kW in Heavy Duty operation. The appropriate rating depends on the motor load and the application’s overload requirements.
Yes. The Unidrive SP supports open-loop control modes that do not require encoder feedback. Closed-loop operation requires the appropriate feedback arrangement and configuration.
The drive includes a two-wire RS-485 serial interface and supports Modbus RTU communication. Additional industrial protocols may be available through compatible option modules.
Compare the supply voltage, motor current, Normal Duty and Heavy Duty ratings, control mode, feedback requirements and installed option modules. Also verify the control wiring and parameter configuration before commissioning the replacement.