Description
Control Techniques Unidrive SP4403
Product Introduction
The Control Techniques Unidrive SP4403 is a frame-size 4 industrial AC drive designed for high-power motor control in three-phase 380–480 VAC systems. The drive belongs to the Unidrive SP platform and can be configured for several operating modes rather than being restricted to conventional V/Hz speed control. Published documentation identifies open-loop V/Hz, open-loop vector, rotor-flux control, closed-loop vector and servo operation as supported modes. This makes the Control Techniques Unidrive SP4403 applicable to both standard induction-motor installations and applications requiring encoder or other feedback-based control.
The most important selection issue with the Control Techniques Unidrive SP4403 is its two principal current ratings. In Normal Duty, the drive is rated at 104 A and approximately 55 kW / 75 hp. In Heavy Duty, the rating is 96 A and approximately 45 kW / 60 hp. These are not interchangeable labels; the lower Heavy-Duty rating provides the current capacity required for more demanding motor-load conditions. A pump or fan with relatively predictable loading may use the Normal-Duty rating, while high-inertia or high-torque machinery must be evaluated against the Heavy-Duty rating and applicable overload requirements.
The SP4403 also provides onboard PLC functionality, PID control, analog and digital I/O, pulse-train capability, and an RS-485 Modbus RTU interface. Optional modules can add communication networks such as PROFIBUS-DP, DeviceNet, CANopen, EtherCAT, EtherNet/IP, PROFINET and other interfaces. The drive is panel mounted and carries an IP20 enclosure rating, so the surrounding cabinet must provide the required environmental protection.
Technical Specifications
| Parameter | Specification |
|---|---|
| Product Model | SP4403 |
| Manufacturer | Control Techniques |
| Product Series | Unidrive SP |
| Product Type | AC variable-frequency / servo drive |
| Frame Size | 4 |
| Input Voltage | 380–480 VAC |
| Input Phase | 3-phase |
| Input Frequency | 48–65 Hz |
| Normal-Duty Continuous Current | 104 A |
| Normal-Duty Motor Rating | Approx. 55 kW / 75 hp |
| Heavy-Duty Continuous Current | 96 A |
| Heavy-Duty Motor Rating | Approx. 45 kW / 60 hp |
| Maximum Output Frequency | Up to 550 Hz |
| Control Modes | V/Hz, open-loop vector, RFC, closed-loop vector, servo, regenerative |
| Standard Communication | RS-485, Modbus RTU |
| Analog Inputs | 3 |
| Analog Outputs | 2 |
| Digital I/O | Built-in digital inputs/outputs; exact terminal allocation depends on configuration |
| Feedback | Encoder interface; optional feedback modules available |
| Option Slots | 3 |
| PLC Function | Onboard programmable logic |
| PID | Built-in PID controller |
| Enclosure Rating | IP20 |
| Mounting | Surface/panel or through-panel |
| Ambient Operating Temperature | 0–40°C standard rating |
| Storage Temperature | Approximately -40 to +70°C |
| Dimensions | Approximately 510 × 310 × 298 mm |
| Weight | Approximately 30–34 kg, depending on documented configuration/source |
| Typical Applications | Fans, pumps, conveyors, compressors, extruders, winders, hoists, packaging and printing |
The dimensions and weight vary slightly between published records, so the actual installation drawing should be used when cabinet clearance is critical. The 96 A Heavy-Duty and 104 A Normal-Duty ratings are consistently reported across the available product records.
Unidrive SP4403
Main Features and Engineering Considerations
Dual-Duty Current Rating
The needs to be selected by current and load duty, not simply by motor horsepower. The Normal-Duty rating is 104 A / 55 kW, while Heavy Duty is 96 A / 45 kW. The motor nameplate current and actual load profile should be checked against the applicable rating.
Multiple Motor-Control Modes
The Unidrive SP architecture supports V/Hz, open-loop vector, RFC, closed-loop vector, servo and regenerative operation. This allows one hardware platform to serve substantially different machine requirements, but the parameter set must match the motor, feedback device and selected control mode.
Feedback Capability
Encoder and resolver-related options are available for applications requiring closed-loop speed or position control. A replacement drive should therefore be checked against the feedback option installed on the original unit before commissioning.
Built-In PLC and PID Functions
The includes onboard PLC functionality and PID control. This can be important in legacy machinery where part of the machine sequence or process regulation is implemented inside the drive rather than entirely in an external PLC.
Communications
Modbus RTU over RS-485 is available as the standard serial interface. Network expansion is possible through option modules, including PROFIBUS-DP, CANopen, EtherCAT, EtherNet/IP and PROFINET. Do not assume that every has these networks physically installed; the option-card configuration must be checked.
Legacy Platform Consideration
The Unidrive SP is a legacy Control Techniques platform and has entered phase-out status in some supply channels. Current inventory records describe availability as limited. For an existing machine, retaining a tested spare and preserving the parameter configuration can be more practical than treating the drive as a current-generation standard component.
Application Scenarios
Pumps and Fans
Suitable for variable-speed applications where Normal-Duty current capacity is adequate.
Conveyors
Vector control can provide improved speed and torque behavior compared with basic V/Hz control.
Compressors
The drive can support controlled acceleration, speed regulation and process PID functions.
Extruders and Winders
Feedback-based control and the available high-performance modes make the platform suitable for applications requiring tighter speed or torque regulation.
Hoists and High-Inertia Machinery
These applications require careful Heavy-Duty rating and overload evaluation. The 96 A Heavy-Duty rating should not be replaced with the 104 A Normal-Duty figure simply because the motor horsepower appears acceptable.
Legacy Machine Retrofit
The is particularly relevant when maintaining existing Unidrive SP installations where cabinet dimensions, wiring, option cards and established parameter files need to be retained.
Engineer’s Guide: Field Pitfalls
Check the duty rating first. is 104 A / 55 kW in Normal Duty but 96 A / 45 kW in Heavy Duty.
Do not size solely by horsepower. Motor full-load current, overload profile, switching frequency, ambient temperature and application duty all matter.
Preserve the parameter file. An apparently identical replacement drive can behave differently if the motor data, ramp settings, current limits, feedback configuration or control mode are not restored correctly.
Identify option modules. Communication and feedback cards can materially change how the drive integrates with the machine PLC and motor.
Check encoder wiring. Closed-loop operation depends on the correct feedback device and corresponding option-card configuration.
Verify the incoming supply. The is a 380–480 VAC three-phase drive. Do not substitute a 200/230 VAC variant based only on the SP series name.
Allow for cabinet heat. IP20 means the drive is intended for installation inside an appropriate enclosure rather than direct exposure to plant conditions.
Check mechanical clearance. The frame-size 4 unit is approximately 510 mm high and 310 mm wide, with published depth around 298 mm.
Check braking requirements. High-inertia loads may require an appropriate braking arrangement and resistor configuration; do not assume the installed machine’s braking circuit can simply be transferred without verification.
Check communication hardware. Modbus RTU is standard, while higher-level industrial Ethernet or fieldbus functions generally depend on installed option modules.
Frequently Asked Questions
What is the Control Techniques ?
The is a frame-size 4 Unidrive SP variable-frequency and servo drive for three-phase 380–480 VAC systems.
What is the power rating?
It is rated approximately 55 kW / 75 hp at 104 A in Normal Duty and 45 kW / 60 hp at 96 A in Heavy Duty.
Is a servo drive?
The Unidrive SP platform can operate in servo mode with compatible permanent-magnet/brushless motors and feedback devices. The exact application requires the appropriate motor, feedback hardware and parameter configuration.
What input voltage does use?
The is a three-phase 380–480 VAC drive.
Does support Modbus?
Yes. The drive provides RS-485 with Modbus RTU. Other communications such as EtherCAT, EtherNet/IP, PROFINET and PROFIBUS-DP can be added through suitable option modules.
Does have PLC functionality?
Yes. The published specifications identify onboard PLC functionality and a built-in PID controller.
What is the protection rating?
The standard is IP20. It therefore requires suitable cabinet installation for industrial environments.
Is still a current-generation drive?
The Unidrive SP platform is a legacy product family, and current supply records describe the as being in phase-out or limited-stock status. Existing installations should therefore be managed with attention to spare availability and parameter backup.
Procurement Note
For a Control Techniques Unidrive , specify the complete model number together with the installed option cards and application duty.
Before purchasing a replacement, verify:
- exact model marking.
- 380–480 VAC three-phase input.
- Normal-Duty versus Heavy-Duty application.
- Motor nameplate current.
- Existing feedback card.
- Existing communication card.
- Braking resistor and braking configuration.
- Keypad/display configuration.
- Stored parameter set.
- Physical frame size and cabinet clearance.
- Drive firmware/software compatibility where applicable.
- Terminal and control-wiring condition.
The most important issue is the 96 A Heavy-Duty versus 104 A Normal-Duty distinction. A replacement selected only from the 55 kW / 75 hp figure can be undersized for a high-overload application.
For an existing Unidrive SP installation, preserve the original parameter file and option-card configuration before replacement whenever possible. This is usually more valuable than relying on default drive settings after installing a replacement unit.
