SKB3400075 - Variable speed drive - CONTROL TECHNIQUES

Control Techniques SKB3400075 frequency inverter - Digidrive SK 480 V

The frequency inverter SKB3400075 is a model in the Digidrive SK series from Control Techniques (part of the Nidec Leroy-Somer group). Designed to drive three-phase AC induction motors, it covers a rated power of approximately 0.75 kW or 1 HP, with a 400 to 480 V three-phase supply and a typical output current close to 2.1 A. Built for panel integration in an open chassis format, it is aimed at general industrial applications where speed stability, motor protection and ease of commissioning are priorities. The Digidrive SK platform implements a DSP for PWM modulation with an adjustable carrier frequency, providing fine flux control and reduced electrical noise. Configurable acceleration and deceleration ramps ensure controlled transitions, limiting mechanical stress on the installation. This reference naturally integrates into modern automation architectures controlled by a programmable logic controller while remaining straightforward to deploy for local remote control.

Technical specifications

• Manufacturer reference : SKB3400075
• Series : Digidrive SK
• Manufacturer : Control Techniques
• Type : Variable speed drive for AC induction motors, open chassis for cabinet mounting
• Supply voltage : 400 to 480 V AC three-phase, 50/60 Hz
• Rated power : 0.75 kW, 1 HP
• Rated output current : approximately 2.1 A depending on application conditions
• Output voltage : 0 to 480 V AC three-phase
• Control modes : V/f and sensorless vector control in open loop
• Switching frequency : PWM with carrier frequency adjustable via DSP
• Inputs/outputs : analog inputs for speed setpoint, configurable logic inputs for start, stop, reverse and preset speeds
• Motor protection : built-in overload, overcurrent and overvoltage monitoring functions

Overview of the Digidrive SK series

The Digidrive SK series is a family of compact drives dedicated to standard industrial drive applications. It targets simple parameterization, service reliability and energy optimization for induction motors. DSP-based digital processing controls the PWM synthesis to precisely adjust the voltage and frequency supplied to the motor. As a result, speed is maintained with good stability over a wide range, while losses and audible switching noise can be optimized according to the operating context. Configurable ramps, controlled stopping and integrated protection functions help improve machine reliability and reduce mechanical wear. Thanks to its open chassis format, the series facilitates integration into existing electrical cabinets, including retrofits where obsolescence requires identical replacement or functional compatibility.

• Available controls : V/Hz regulation for simplicity and sensorless vector control to improve low-speed torque and dynamic performance without an encoder
• Basic automation features : preset speeds, forward/reverse management, adjustable ramps, integrated protections and local or software-based configuration interface

The SKB3400075 belongs to the 480 V supply class and targets motors around 0.75 kW. It provides a sensible solution to stabilize speed, improve overall efficiency and adapt drive behavior to process requirements without unnecessary complexity. In systems controlled by a programmable logic controller, it integrates as a speed drive with standard logic commands or via communication interfaces available depending on configuration.

Industrial applications

This drive is deployed in production installations where control of speed and ramps affects output quality, consumption and equipment lifetime. Its ability to deliver usable torque at low speed in sensorless vector mode makes it a strong candidate for many general drive applications.

• Conveying and light handling : fine speed adaptation, progressive starts, reduction of mechanical jolts
• Pumping and ventilation : flow control by frequency, reduced consumption at partial load
• Packaging and process machines : simple section synchronization, selection of preset speeds
• Small auxiliary machine tools : feed or accessory drives with adjustable speeds
• Industrial HVAC : control of ventilation and extraction units on 400 to 480 V networks

Integration and communication

The Digidrive SK provides analog inputs for the speed setpoint and configurable logic inputs for main operating commands. Depending on the options chosen, communication cards enable integration on common fieldbuses. This modular approach facilitates connection to a digital control system or a programmable logic controller, while retaining direct commissioning when only local control is required.

Parameterization is performed via the keypad and local interface, and can be supplemented by software tools for commissioning depending on configuration. The menu and parameter structure of the series promotes quick familiarization, with access to essential functions such as ramps, current limits, thermal protections and selection of control modes. For applications requiring very high dynamics and encoder closed-loop control, a dedicated servo drive remains preferable. For a standard induction motor drive, the SKB3400075 offers a robust compromise between performance, simplicity and total cost of ownership.

Availability and warranty

The Control Techniques SKB3400075 drive is available refurbished or as exchange units, bench-tested. Standard Exchange Industry ensures responsive logistics with shipping within 24 to 72 hours to many countries. Depending on the chosen service, a warranty of 6 to 24 months is applied. In case of line stoppage or obsolescence, our technical team will assist you to confirm power, supply voltage and control mode compatibility with your motor and automation architecture, and to propose a functional alternative if necessary.