Emerson UNI4402 – High-Performance AC Variable Frequency Drive | Unidrive Platform
The Emerson UNI4402 is a 4.0 kW (5.5 HP), 400 V three-phase AC variable frequency drive from the Control Techniques Unidrive series — one of the most widely deployed open-loop and closed-loop drive platforms in industrial automation. Designed for demanding motor control applications, the UNI4402 delivers precise speed regulation, robust protection, and seamless integration with major fieldbus networks. Konmask.com supplies this unit as a verified, traceable component for OEM builders, system integrators, and MRO procurement teams.
Complete Technical Specifications
| Part Number | UNI4402 |
| Brand / Manufacturer | Emerson / Control Techniques |
| Series | Unidrive |
| Output Power | 4.0 kW / 5.5 HP |
| Input Voltage | 380–480 V AC, 3-Phase |
| Output Voltage | 0–480 V AC, 3-Phase |
| Output Current (Nominal) | 9.5 A |
| Output Frequency Range | 0–1000 Hz |
| Control Modes | Open-loop V/Hz, Open-loop Vector, Closed-loop Vector, Servo |
| Enclosure Rating | IP20 (chassis mount) |
| Ambient Temperature | 0 °C to +40 °C (derate above 40 °C) |
| Cooling Method | Forced air (internal fan) |
| Communication Options | RS-485 (Modbus RTU); optional PROFIBUS, DeviceNet, CANopen modules |
| Analog Inputs | 2 × ±10 V / 0–20 mA configurable |
| Digital I/O | 6 digital inputs, 3 relay outputs |
| Braking | Internal braking transistor (external resistor required) |
| Protection Features | Overcurrent, overvoltage, undervoltage, overtemperature, phase loss, earth fault |
| Weight | Approx. 460 g (drive module) |
| Standards | CE, UL, cUL, EN 61800-3 |
Proven Application Environments
The UNI4402 is field-proven across a broad range of industrial sectors where precise motor speed control is critical:
- Conveyor & Material Handling: Smooth acceleration/deceleration profiles reduce mechanical stress on belts and rollers in logistics and packaging lines.
- Pump & Fan Control: Energy-saving V/Hz mode reduces power consumption by up to 50% versus across-the-line starting in HVAC and water treatment systems.
- CNC & Machine Tool Spindles: Closed-loop vector mode delivers constant torque at low speeds for precision machining centers.
- Textile & Winding Machinery: High-resolution speed regulation maintains consistent tension across multi-axis winding applications.
- Food & Beverage Processing: Hygienic-compatible installation with IP20 chassis in sealed control cabinets; supports washdown environments when panel-mounted.
- Printing & Converting: Synchronised multi-drive operation via fieldbus for register control in web-fed printing lines.
- Compressors & Blowers: Soft-start capability eliminates inrush current spikes, extending compressor service life.
Engineering Advantages
- Universal Control Architecture: Single drive platform supports V/Hz, open-loop vector, closed-loop vector, and servo modes — reducing spare-parts inventory across mixed-motor installations.
- Wide Fieldbus Ecosystem: Native RS-485 Modbus RTU plus optional plug-in modules for PROFIBUS DP, DeviceNet, and CANopen enable drop-in integration with Siemens, Allen-Bradley, and Mitsubishi PLCs.
- High Output Frequency: 0–1000 Hz output range supports high-speed spindle motors and specialized servo applications without external signal conditioning.
- Integrated Braking Transistor: Eliminates the need for a separate braking chopper in most duty cycles; simply add an external resistor sized to the application.
- Compact Chassis Form Factor: Slim DIN-rail-compatible profile minimises panel footprint in space-constrained enclosures.
- Comprehensive Protection Suite: Multi-layer fault detection (overcurrent, overvoltage, phase loss, earth fault, overtemperature) reduces unplanned downtime and protects connected motors.
System Architecture & Signal Flow
The UNI4402 operates within a standard AC drive signal chain:
- Power Input Stage: 380–480 V 3-phase AC → internal EMC filter → rectifier bridge → DC bus (approx. 540–680 V DC).
- DC Bus & Braking: Bulk capacitor bank smooths DC bus; internal IGBT braking transistor clamps regenerative energy to external resistor.
- Inverter Output Stage: IGBT-based PWM inverter synthesises variable-frequency, variable-voltage 3-phase output to motor terminals.
- Control Board: DSP-based control loop processes speed/torque reference from analog inputs or fieldbus; executes selected control mode algorithm (V/Hz / vector / servo).
- I/O Interface: Digital inputs accept run/stop, direction, preset speed, and fault reset commands; relay outputs signal run status, fault, and at-speed conditions to PLC or SCADA.
- Communication Layer: RS-485 port provides Modbus RTU access to all drive parameters and real-time process variables (speed, current, torque, fault codes).
Sourcing & Quality Verification
- All UNI4402 units supplied by Konmask.com are sourced through verified industrial distribution channels with full traceability to authorised Control Techniques / Emerson supply chains.
- Each unit undergoes incoming inspection: label verification, firmware version check, and functional power-up test prior to dispatch.
- Original manufacturer packaging, documentation, and warranty seals are preserved where available.
- Counterfeit-risk assessment performed on every batch; units failing inspection are quarantined and not listed for sale.
Procurement Process
- Enquire: Contact Konmask.com via email or phone with your required quantity and delivery timeline.
- Quote: Receive a formal quotation with unit price, lead time, and shipping options within 24 hours.
- Order Confirmation: Submit PO or online order; payment via T/T, PayPal, or trade credit (approved accounts).
- Inspection & Dispatch: Unit inspected, packed, and dispatched with tracking within 1–3 business days.
- After-Sales Support: Technical support available for installation, parameter setup, and fault diagnosis.
Technical FAQ
Q: Is the UNI4402 compatible with permanent magnet (PM) motors?
A: The standard Unidrive firmware supports induction motors in all modes. PM motor support requires the Unidrive SP or M series with appropriate firmware — confirm motor type before ordering.
Q: What external braking resistor is recommended for the UNI4402?
A: For a 4 kW drive at 400 V, a minimum resistance of 72 Ω rated at ≥200 W continuous (≥1 kW peak) is typical. Exact sizing depends on duty cycle and load inertia — consult the Unidrive engineering guide.
Q: Can the UNI4402 be used with a single-phase input supply?
A: No. The UNI4402 requires a balanced 3-phase 380–480 V input. Single-phase operation will damage the rectifier bridge and void warranty.
Q: What is the difference between UNI4402 and UNI4403?
A: The UNI4403 is the next frame size up (5.5 kW / 7.5 HP) in the same Unidrive series. Both share identical control architecture and parameter sets; only the power stage and current rating differ.
Q: Does Konmask.com provide parameter backup files or commissioning support?
A: Yes. Our technical team can provide standard parameter templates for common applications and remote commissioning guidance via email or video call.
© 2026 Konmask.com. All rights reserved.
Original Source: https://Konmask.com
Contact: [email protected] | +0086 19859288691







