NORD NORDAC SK700E Modules: SK700E-551-340-A

Technical Dossier

Product Details And Specifications

NORD NORDAC SK700E Series: Comprehensive Module Range and Technical Overview

The NORDAC SK700E is a modular frequency inverter series developed by NORD Drivesystems (Getriebebau NORD GmbH & Co. KG), engineered for demanding continuous-duty applications in heavy industry. Installed across chemical processing plants, oil refineries, water treatment facilities, pulp and paper mills, and marine propulsion systems, the SK700E platform occupies a critical position in global industrial automation infrastructure. Its distributed intelligence architecture — where I/O expansion, fieldbus communication, and parameter storage are handled by plug-in option modules rather than integrated firmware — makes it a preferred choice for plant engineers who require deterministic control behavior and long-term spare parts availability. Installed base units remain operational in facilities with 15–25 year maintenance cycles, making lifecycle parts sourcing a primary procurement concern for maintenance engineers worldwide.

The Evolution of NORDAC SK700E Architecture

The SK700E succeeded the earlier SK700 and SK750E platforms, inheriting the NORD POSICON positioning control philosophy while introducing a standardized option slot system. Early SK700E units (circa 2005–2010) relied on RS-485 serial communication via the SK TU3-PAR parameter box for commissioning. Subsequent hardware revisions introduced direct PROFIBUS-DP integration via the SK TU3-PBR and SK TU3-CAO CANopen modules, enabling seamless integration into Siemens S7 and Rockwell ControlLogix DCS environments. The SK700E-5 sub-series (denoted by the -5xx suffix in the option module part number) introduced enhanced I/O expansion capability, supporting up to 6 additional digital inputs, 2 analog inputs (0–10 V / 4–20 mA), and 2 relay outputs per expansion card. By 2015, NORD transitioned primary development focus to the NORDAC FLEX SK 200E and NORDAC LINK SK 250E platforms for new installations, placing the SK700E into a sustained production / mature lifecycle phase. Existing SK700E installations in refineries and chemical plants continue to operate under long-term service agreements, with NORD and authorized distributors maintaining spare module inventory through at least 2030.

NORDAC SK700E Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked modules within the NORDAC SK700E option and expansion ecosystem. Each entry reflects a discrete hardware function. Modules are not interchangeable across function categories.

I/O Expansion Modules

• SK700E-551-340-A: I/O expansion module, 6DI / 2AI / 2 relay outputs, 24 VDC logic, plug-in option slot
• SK700E-551-340-B: I/O expansion module, revised PCB revision B, enhanced EMC filtering, direct replacement for -A variant
• SK700E-551-110-A: Basic I/O module, 4DI / 1AI / 1 relay output, entry-level expansion for standard conveyor duty
• SK700E-551-220-A: Mid-range I/O module, 4DI / 2AI / 2DO, supports PTC thermistor input for motor protection

Fieldbus Communication Adapters

• SK TU3-PBR: PROFIBUS-DP slave adapter, 12 Mbit/s, GSD file configurable, for SK700E option slot
• SK TU3-CAO: CANopen DS301/DS402 adapter, 1 Mbit/s, EDS file configurable
• SK TU3-EIP: EtherNet/IP adapter, 100 Mbit/s, CIP motion profile, for SK700E and SK750E
• SK TU3-PNT: PROFINET IO device adapter, RT class 1, 100 Mbit/s, GSDML configurable
• SK TU3-MOD: Modbus RTU/TCP adapter, RS-485 / RJ45 dual interface
• SK TU3-DEV: DeviceNet adapter, Group 2 slave, 500 kbit/s

Parameter Storage & Commissioning Modules

• SK TU3-PAR: Parameter storage module, non-volatile EEPROM, enables drive cloning and parameter backup without PC
• SK TU3-CTR: Control terminal expansion, additional analog I/O channels, for multi-zone tension control

Encoder & Feedback Modules

• SK TU3-ENC: Incremental encoder interface, HTL/TTL, 5–30 VDC, max 300 kHz input frequency
• SK TU3-SSI: SSI absolute encoder interface, 25-bit resolution, for closed-loop positioning applications
• SK TU3-RES: Resolver interface module, 2–10 Vrms excitation, for high-vibration environments

Safety & Braking Modules

• SK TU3-STO: Safe Torque Off (STO) module, SIL 2 / PLd certified, IEC 62061 compliant, for press and hoist applications
• SK BRE4-xxx: External braking resistor assembly series, matched to SK700E power ratings from 0.37 kW to 75 kW

Sourcing Hard-to-Find & Obsolete NORDAC SK700E Parts

DriveKNMS maintains a dedicated inventory program for NORDAC SK700E option modules, with particular focus on I/O expansion cards (SK700E-551-xxx series) and fieldbus adapters that have been discontinued from NORD's standard production schedule. For plant operators running SK700E drives in critical process loops — where a single failed I/O module can halt an entire production line — DriveKNMS provides the following sourcing services: verified surplus stock from decommissioned plant equipment, factory-refurbished modules with full functional test certification, cross-reference identification for obsolete part numbers to current NORD catalog equivalents, and emergency same-day dispatch for in-stock items. All SK700E modules sourced through DriveKNMS are accompanied by a test report and 12-month warranty against manufacturing defects. For end-of-life planning, DriveKNMS can assist maintenance teams in identifying compatible migration paths to the NORDAC FLEX or NORDAC LINK platforms while maintaining existing motor and cabling infrastructure.

Quality Control for the NORDAC SK700E Range

NORDAC SK700E option modules incorporate a multi-layer PCB backplane with proprietary NORD option bus (NOB) protocol. Standard bench testing procedures are insufficient for validating module integrity. DriveKNMS applies a dedicated test protocol for each SK700E module category: I/O expansion modules (SK700E-551-xxx) are tested under live 24 VDC logic with all digital input channels individually stimulated and relay output switching verified under rated load. Analog input channels are calibrated against a traceable 4–20 mA / 0–10 V reference source. Fieldbus adapters (SK TU3-PBR, SK TU3-CAO, SK TU3-EIP, SK TU3-PNT) are validated using a live SK700E host drive with active network master (Siemens S7-300 for PROFIBUS, Rockwell CompactLogix for EtherNet/IP) to confirm full cyclic data exchange and parameter access. Encoder modules are tested at 100 kHz and 300 kHz input frequencies. All modules pass a 4-hour burn-in cycle at 45°C ambient before release. Test records are retained for 5 years and available on request.

For NORDAC SK700E module sourcing, technical cross-reference, or lifecycle support inquiries:

• Email: [email protected]
• WhatsApp: +86 18359293191
• Web: driveknms.com
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