SKD3400550 - Variable speed drive - CONTROL TECHNIQUES

Variable speed drive SKD3400550 - UNIDRIVE SK - CONTROL TECHNIQUES

The variable speed drive SKD3400550 is part of the UNIDRIVE SK series from CONTROL TECHNIQUES, a widely deployed range for controlling induction motors in industrial environments. Designed for reliable regulation of speed and torque, it targets maintenance teams, system integrators and machine builders seeking a stable, easy-to-configure solution compatible with existing automation architectures. The UNIDRIVE SK range covers common needs for conveying, pumping, ventilation and continuous processes, with mechanical and functional variants suited to compact cabinet constraints. The SKD3400550 model fits into the SK family chassis, offering basic features focused on energy efficiency, soft start, configurable ramps and motor protections. Exact electrical parameters, power and interfaces depend on the version and options fitted. This datasheet provides a structured overview to verify suitability for your application and prepare integration with a programmable logic controller or numerical controller.

Technical specifications

• Manufacturer reference : SKD3400550
• Range : UNIDRIVE SK
• Manufacturer : CONTROL TECHNIQUES
• Type : Variable speed drive for AC induction motors, cabinet mounting
• Supply voltage : per configuration, single-phase or three-phase as indicated on the nameplate
• Rated power : determined by the specific SKD variant, values given in kW and HP per factory documentation
• Rated output current : depends on the selected sizing, in accordance with the manufacturer's data for the installed SKD3400550 version
• Output voltage : three-phase, PWM-modulated, amplitude and frequency according to control parameters
• Control mode : V/Hz and open-loop vector, availability depending on configuration and options of the UNIDRIVE SK range
• Switching frequency : configurable within the range provided by the series, to be adjusted according to EMC and acoustic constraints
• Operator interface : local keypad and display depending on version, parameterisation possible via the manufacturer's commissioning software
• EMC filters : integrated or add-on depending on the variant, EMC compliance to be checked against the installation site
• Inputs/outputs : logical and analog I/O available depending on configuration, for start/stop commands, speed setpoint and status signals
• Protection functions : motor thermal protection, overvoltage and overcurrent monitoring, configurable trips
• Degree of protection : typically IP20 in cabinet, to be confirmed according to the supplied version

Overview of the UNIDRIVE SK range

The UNIDRIVE SK series groups compact frequency drives intended for reliable control of induction motors in industrial installations. It favours ease of deployment, compatibility with standard control signals and a feature set focused on the typical needs of production lines. Units in this family come in several mechanical sizes to optimise cabinet layout, with accessories for EMC attenuation, appropriate braking resistors and optional communication modules. In sites where frequency drives, servo drives and PLCs coexist, UNIDRIVE SK represents a robust drive building block, designed to ensure operational continuity and reproducible production cycles. In maintenance, clear parameters and the availability of predefined application profiles simplify like-for-like replacement and fast return to service.

• Application-oriented control : typical profiles for conveying, pumping and ventilation with configurable acceleration and deceleration ramps
• Modular ecosystem : optional I/O and communication cards to match connectivity to the existing architecture

Beyond basic functions, the range emphasises consistency of diagnostics and protections. Structured fault codes, quick access to key parameters and the manufacturer's software tools support a methodical maintenance approach. The goal is to minimise downtime by enabling rapid identification of root causes and controlled restart. For integrators, standardisation of terminals, menus and options simplifies duplication of schematics between machines, while retaining the flexibility to fine-tune performance according to load, expected dynamics and level of interaction with the central controller.

Industrial applications

The SKD3400550 is used in many processes where speed stability, repeatability and compatibility with industrial interfaces are required. It meets the needs of continuous production workshops, packaging lines and industrial utilities. The following use cases illustrate common integrations:

• Conveyors and material handling : speed regulation, basic synchronization between sections, adaptation to load variations
• Pumps and compressors : energy optimisation by adjusting the setpoint, reduction of hydraulic shocks
• Industrial ventilation and HVAC : control of fans with analog setpoints or fieldbus
• Packaging : control of belt and roller speeds, quick format changes
• Food and beverage : steady throughput, soft starts to protect mechanisms
• Textile and paper : line speed holding, tension control via external loops
• Special machines : integration with PLCs and process sensors for tailored sequences
• Water treatment : flow modulation on pumps, pressure surge limitation and energy savings

Integration and communication

Integration of the SKD3400550 is typically done via digital and analogue inputs/outputs for start, stop, direction and speed setpoint functions. For advanced supervision, UNIDRIVE SK communication modules enable connection to common fieldbuses, for example Modbus, CANopen or PROFIBUS-DP, depending on the cards available and the chosen version. This connectivity allows centralized control from a PLC, CNC or SCADA system.

Commissioning relies on the local keypad and the manufacturer's software for status reading, parameter editing and configuration saving. Integrated protection functions, combined with diagnostics, contribute to operational reliability. EMC compliance and selection of filtering options must be determined based on the site, cable lengths and the supply network. Selection of power, cooling and accessories, notably braking resistor and inductors, is based on the motor nameplate, the duty cycle and the desired thermal margins.

Availability and warranty

Standard Exchange Industry supplies the SKD3400550 as new supply, exchange unit or repair. Each unit supplied is bench-tested according to documented procedures. Shipping is handled within 24 to 72 hours to over 120 countries. A warranty applies depending on the chosen service. In case of obsolescence or end of production, our technical team will assist in identifying an equivalent within the UNIDRIVE SK range and qualify electrical, mechanical and functional compatibility with your installation. To prepare your request, provide the exact reference, motor power, supply voltage, type of control used and, if applicable, the communication modules installed. This helps secure the replacement and reduce line downtime.