Control Techniques UNI4402REGEN Regenerative AC Drive Unit

Module Feature

UNI4402REGEN belongs to Control Techniques Unidrive Classic series regenerative AC drive. Model decoding: UNI4402 = 55kW rating, REGEN = integrated active regenerative power stage. Different from ordinary drives with brake resistor, this model can feed motor braking energy back to the power grid, save energy and avoid heat accumulation. It supports V/F control, open-loop vector and encoder closed-loop vector control, stable low-speed high torque output. Rich expandable options including encoder card, PROFIBUS and DeviceNet communication modules. Widely used for cranes, hoists, material elevators, dynamic test benches and centrifuge equipment with frequent acceleration and deceleration. This model has been discontinued, mainly supplied as refurbished spare parts for legacy automation systems.

Working principle

Three-phase AC input passes through active regenerative rectifier unit, bidirectional energy flow is realized between AC grid and DC bus. When motor runs in electric state, grid supplies power to motor; when braking, motor generates electricity, the drive converts regenerative power into sinusoidal AC and feeds back to power grid. The inverter IGBT unit adjusts output frequency and voltage for motor speed regulation. Vector algorithm independently controls excitation current and torque current to guarantee high-precision speed and torque performance.

Onboard components

Active regenerative rectifier bridge, IGBT inverter power module, DC bus capacitor bank, main control motherboard, encoder feedback interface, digital & analog I/O terminal block, cooling fan group, operation panel interface, EMC filter assembly.

LED indicators

Front panel LED indicators for power, run, fault and alarm; supporting keypad displays frequency, current, DC bus voltage and fault code information.

Hardware self‑diagnosis

Power-on self-check covers overvoltage, undervoltage, overcurrent, overtemperature, motor overload, encoder loss, grid phase missing and regeneration circuit abnormality. Fault codes and event logs are stored in drive memory.

Programming software

Parameter commissioning, auto-tuning and fault diagnosis use Control Techniques CTSoft software; local parameter modification via compatible operator keypad.

Electrical & Process Parameters

Model:UNI4402REGEN Brand:Control Techniques Device type:Regenerative Vector AC Drive Rated power:55 kW Rated supply:3‑phase 380‑480V AC Output current:124 A Control mode:V/F, open-loop vector, closed-loop vector Energy mode:Bidirectional, active regeneration to grid Function:Speed and torque control for heavy-duty equipment with frequent braking

Mechanical & Structure

Mounting:Cabinet backplane mounting Protection class:IP20 Housing:Metal enclosed cabinet with forced air cooling

Environmental

Operating temperature:0℃ ~ +40℃ (derating above 40℃) Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing Certification:CE compliant Status:Discontinued legacy regenerative drive, spare for old production line replacement

Installation

Mount drive on cabinet backplane and reserve cooling clearance. Complete three-phase grid power, motor cable, shielded encoder wire and control signal wiring. Pay attention to grid harmonic matching requirement for regenerative models. Input motor nameplate parameters, run motor auto-tune, configure speed or torque mode before commissioning.

Interface

Three-phase power terminal, motor output terminal, encoder feedback port, analog/digital I/O terminals, keypad socket, communication expansion slot.

Diagnostic

Overvoltage alarm during braking:Regeneration circuit failure or grid impedance mismatch. Overcurrent fault:Motor cable short circuit, insulation breakdown or acceleration ramp time too short. Overtemperature alarm:Fan damage, radiator dust clogging, poor cabinet ventilation. No encoder feedback:Encoder cable open circuit or signal type parameter setting error.

Product Brief

Control Techniques UNI4402REGEN Unidrive Classic 55kW regenerative vector drive, 400V three-phase, active grid feedback for braking energy, closed-loop vector control, suitable for hoists, test benches and other heavy-duty equipment with frequent start-stop.