SK3,5T - Variable speed drive - LEROY SOMER

Leroy Somer SK3,5T frequency drive - DIGIDRIVE SK

The SK3,5T inverter is part of the DIGIDRIVE SK series from manufacturer Leroy Somer. Designed for three-phase induction motors, it meets the needs of operators and maintenance teams looking for reliable speed and torque control, reduced mechanical stress at start-up and improved energy efficiency on variable-load applications. Powered by 380-480 V three-phase supply and sized for a motor power of 2.2 kW (approx. 3 CV), it delivers a rated output current of 5.1 A using an open-loop sensorless vector control, ensuring robust low-speed torque performance without feedback instrumentation. Commissioning is performed via a display and local keys, according to the DIGIDRIVE SK documentation, with built-in protection functions for both the drive and the motor. This reference is aimed at integrators, maintenance workshops and end users facing obsolescence of existing drives or needing to improve process control on conveying, pumping and ventilation applications.

Technical specifications

• Manufacturer reference: SK3,5T
• Range: DIGIDRIVE SK
• Manufacturer: Leroy Somer
• Type: AC variable speed drive for three-phase induction motors
• Supply voltage: 380-480 V three-phase, 50/60 Hz
• Rated motor power: 2.2 kW, approx. 3 CV (3 HP)
• Rated input current: 7.3 A
• Rated output current: 5.1 A
• Output voltage: suitable for driving three-phase motors in the 380-480 V range
• Control mode: Open-loop sensorless vector control for improved torque stability
• Operator interface: Display and local keys for simplified configuration
• Protection functions: Built-in protections to safeguard the drive and the motor

DIGIDRIVE SK range overview

The DIGIDRIVE SK series from Leroy Somer brings together frequency inverters intended for common industrial drive applications, focusing on ease of deployment, compactness and energy efficiency. The sensorless vector control enables finer torque regulation at low speed compared with a standard V/f law, resulting in smoother start-ups and better handling of variable loads. Products in the range are designed to be integrated into new workshops as well as existing lines for replacement of aging equipment, while facilitating maintenance through clear parameterisation and native protection functions. Essential frequency variation features cover many process needs, notably flow, pressure and linear speed control on utilities and conveying mechanisms.

• DIGIDRIVE SK for general applications: Speed variation for conveyors, pumps and fans with low-speed torque control, reduced inrush current at start-up and lowered mechanical stress on gearboxes and couplings.
• Scalability and integration: Local configuration via the integrated interface and options for integration into automation architectures controlled by a programmable logic controller or numerical controller, according to the options documented by the manufacturer.

The SK3,5T model sits in the 2.2 kW band, making it a relevant choice for many workshop machines and utilities, both new and retrofit. Its configuration logic enables quick return-to-service after maintenance intervention, aligning with industrial availability constraints.

Industrial applications

This frequency drive covers a wide spectrum of industrial uses, from light handling to utility management. It helps control energy consumption in variable-load processes and promotes smoother operation of mechanical components while ensuring repeatable setpoint changes.

• Conveying and sorting: Drive for belt or roller conveyors, section synchronization and transfer speed adjustment with sensorless vector control.
• Industrial pumping: Flow and pressure regulation on centrifugal pumps with smooth starts limiting water hammer and mechanical fatigue.
• Ventilation and air handling: Control of fans and extractors to adapt speed to demand, in an energy-saving approach for utilities.
• Packaging: Speed variation on unwinders, rewinders and auxiliary drive shafts where low-speed torque stability is required.
• Light handling and assembly: Fine adjustment of feed speeds on assembly mechanisms, motorised vibratory hoppers and feeding systems.

Integration and communication

The DIGIDRIVE SK SK3,5T integrates into systems controlled by a programmable logic controller or a numerical controller via standard control signals and the local operator interface. Configuration is guided by the integrated display and navigation keys, which eases commissioning, parameter duplication and setpoint adjustment directly on site. Built-in protections help maintain installation availability by securing the drive and motor against non-compliant operating conditions, in line with the recommendations of the DIGIDRIVE SK manufacturer documentation.

Within an extended automation architecture, the drive operates as an actuator dedicated to frequency variation, distinct from a servo drive designed for servomotors. It provides the AC-AC conversion suited to induction motors, with sensorless vector regulation to stabilise torque. Control of acceleration and deceleration ramps contributes to maintaining production rates and respecting mechanical constraints, which is particularly useful during preventive and corrective maintenance on lines in production.

Availability and warranty

The Leroy Somer SK3,5T drive is offered by Standard Exchange Industry as tested refurbished units, as standard exchange or as repair of your existing equipment, with warranty depending on the chosen service. Shipping within 24 to 72 hours to over 120 countries. Our technicians assist you to validate electrical compatibility, size the 2.2 kW power and confirm the suitability of the sensorless vector control mode for your application. In case of line stoppage or retrofit needs, we quickly identify the equivalent DIGIDRIVE SK reference and secure the restart as rapidly as possible.