NORD SK 200E NORDAC FLEX Decentralised Frequency Inverter

Overview

The NORD SK 200E series, marketed as NORDAC FLEX, is NORD DRIVESYSTEMS’ most flexible decentralised frequency inverter. Instead of sitting in a central control cabinet, it is installed directly on the motor terminal box or on a wall or machine frame close to the drive. This removes long shielded motor cables, saves cabinet space and simplifies conveyor and materials-handling layouts. The power range runs from 0.25 kW to 22 kW, with IP55 as standard and IP66 as an option.

Seven Star LLC supplies the NORD SK 200E to OEMs, logistics centres, water and wastewater operators and process plants in Oman and the GCC. Our engineers in Muscat help customers choose the correct version, size and bus module, and we provide engineering support for drive projects in Muscat, Sohar, Duqm and Salalah.

Operating Principle

The inverter rectifies the mains supply into a DC link and uses IGBT switching at a pulse frequency of 3 to 16 kHz to create a variable-voltage, variable-frequency output from 0 to 400 Hz. Its sensorless current vector control (ISD) continuously calculates the motor flux and torque-producing current, which gives high starting torque and precise speed control without an encoder. In combination with suitable motor models, the NORD SK 200E drives three-phase asynchronous motors and permanent magnet synchronous motors, and it can also use a linear V/f curve or closed-loop current control with an encoder.

Overload capacity of the NORD SK 200E is 150% for 60 seconds and 200% for 3.5 seconds, enough for conveyor starts and short peaks. A built-in brake chopper allows four-quadrant operation with an internal or external braking resistor, and DC braking is programmable. The drive automatically measures stator resistance to determine accurate motor data, offers four parameter sets that can be switched online, and evaluates motor temperature through a separate PTC or bimetallic input and an I²t model.

Engineering Design of the NORD SK 200E

The NORD SK 200E family has a modular design in four sizes. Variants SK 200E, SK 210E, SK 220E and SK 230E include an integrated 24 V supply, while SK 205E, SK 215E, SK 225E and SK 235E add two potentiometers for minimal configuration and electromechanical brake control. Versions with 1 or 3 in the type designation provide the safe pulse block (STO/SS1), and versions with 2 or 3 add an AS-Interface with four inputs and four outputs. Depending on the variant, the inverter has three or four digital inputs, one or two digital outputs and one or two analogue inputs.

Commissioning is possible with eight DIP switches and potentiometers alone, or with a plug-in SimpleBox or ParameterBox through the RS-232/485 RJ12 interface. Parameters are stored in internal non-volatile memory and can be copied via a plug-in EEPROM, which speeds up series installation and replacement. An integrated PLC and POSICON positioning control reduce the load on the central controller, and optional bus modules connect the drive to PROFINET IO, EtherNet/IP, EtherCAT, POWERLINK, PROFIBUS DP, CANopen and DeviceNet networks.

Key Features

The NORD SK 200E offers the following engineering advantages:

• Power range from 0.25 to 22 kW for single-phase 115 V, single or three-phase 230 V and three-phase 400 V supplies.
• Direct motor mounting or wall mounting close to the motor, with IP55 standard and IP66 optional protection.
• Sensorless current vector control for high starting torque, plus support for asynchronous and PMSM motors.
• Integrated EMC mains filter for Category C2 or C3 and built-in brake chopper for four-quadrant operation.
• Integrated PLC and POSICON positioning, with incremental and CANopen absolute encoder evaluation.
• Safe pulse block STO/SS1 and AS-Interface on selected versions.
• Commissioning by DIP switches and potentiometers, or by plug-in control box and NORDCON software.
• Ethernet and fieldbus connectivity through optional bus modules on the NORD system bus.

Industrial Applications

Decentralised drives such as the NORD SK 200E are the natural choice for long conveyor systems in airports, parcel hubs and warehouses, where dozens of small gear motors are spread over hundreds of metres. The NORD SK 200E is also used on pumps, fans, mixers and agitators in water treatment, food and beverage and bulk handling, where speed control saves energy and reduces mechanical stress during starts. Mounting the inverter on the motor keeps the installation compact and reduces cable cost and interference.

In Oman, typical installations include logistics centres around Muscat, port and bulk handling equipment in Sohar and Duqm, cement and aggregate conveyors and water pumping stations. Seven Star LLC supplies the NORD SK 200E as a trusted supplier and also supports central drives and motors for the same plants, such as the Siemens SINAMICS G120C compact drive, the Schneider Electric Altivar Process ATV630 drive and the WEG W22 IE3 three-phase motor.

Technical Specifications

The NORD SK 200E data below are taken from the NORD manual BU0200, NORDAC FLEX (SK 200E series) Users Manual for Frequency Inverters.

How to Order

To order the NORD SK 200E, send Seven Star LLC an RFQ with the motor power and voltage, preferred mounting (motor or wall), required protection class and the fieldbus or safety functions you need. Our team in Muscat will confirm availability and lead time and provide the NORD BU0200 manual for download. Seven Star LLC supplies NORD DRIVESYSTEMS drive electronics across Oman and the GCC with engineering support in Muscat.