Product Introduction

The SDCS‑FEX‑2 (model number 3ADT306311P2103) is a field‑excitation control module designed for integration into large industrial DC motor drive systems under the ABB DCS platform (notably DCS 500 and DCS 600 series). Its core role is to regulate the field (rotor) current of DC machines, enabling stable and precise machine operation, by controlling the excitation circuit inside the armature converter assembly.

This board is engineered for demanding industrial settings: it supports high‑field voltages (up to ~500 V DC), field current up to 40 A (depending on cooling and configuration) and incorporates both analog and digital signal processing, along with protection features such as over‑current, field loss detection and temperature monitoring. According to vendor specification sheet: dimensions ~14 cm × 20.5 cm × 3.8 cm, weight ~0.32 kg (≈0.71 lbs). Power DCS Parts Limited+2Topbrands PLC Limited+2

The SDCS‑FEX‑2 module is typically mounted as a plug‑in open‑frame PCB inside the converter cabinet, adjacent to the power supply and control boards (such as SDCS‑POW‑1 and SDCS‑CON modules). This arrangement enables tight integration of excitation regulation, monitoring, and control logic.

By enabling fine‑tuned control of field current, the board helps improve motor stability, reduce vibration, optimise machine performance under variable loads, and simplify maintenance via modular replacement.

Technical Parameters

Product Application

The SDCS‑FEX‑2 board is used in a wide range of industrial automation scenarios where DC motors or generators require reliable, modular excitation control. Some examples:

• In large steel‑mill or mining installations, where DC motors drive conveyors, rolling mills or port equipment, the FEX board provides the necessary field current regulation.

• In power‑generation plants where synchronous machines or DC drives are used (for example in auxiliary drives), the board ensures stable rotor excitation and system performance.

• In process automation lines (such as pulp & paper, chemical plants) where DC drives are used and precision of motor control under varying loads is needed.

• In retrofit or modernization of legacy drive cabinets: inserting a modern FEX board enables improved maintainability, serviceability and integration into modern diagnostics network.

• In marine/offshore applications, where efficient and compact excitation modules are needed inside converter racks for propulsion or auxiliary drives.

In these contexts, the SDCS‑FEX‑2 helps reduce downtime, improve control accuracy, simplify module replacement, and support system diagnostics and monitoring.

Product Advantages

• High precision field current control: Ensures that DC machines receive stable, accurate rotor excitation, improving performance and reducing mechanical stress.

• Compact and lightweight design: With weight around 0.32 kg and modest size (≈14 × 20.5 × 3.8 cm), it occupies minimal rack space while delivering full functionality.

• Modular integration: Plug‑in design means fast installation and replacement, reducing downtime and maintenance complexity.

• Enhanced protection features: Built‑in monitoring of overcurrent, field loss, temperature ensures increased reliability and protection of costly drive components.

• Compatibility with DCS platform: Designed to work flawlessly with the DCS 500 / DCS 600 series and their associated control and power boards, simplifying system design.

• Improved maintenance and serviceability: Modular board approach means easier spares management, faster swap‑out and less service time.

• Optimised machine stability: By ensuring correct field current, it helps maintain constant motor performance under varying load, reducing vibration, enhancing lifetime.

• Reduced lifecycle cost: With better control, lower downtime, modular swap‑ability and protection features, total cost of ownership is improved.

Brand Overview

Brand: ABB
ABB is a leading global provider of industrial automation and drive systems. With decades of experience in motor control, power conversion and drive systems, ABB’s modular hardware is widely used across heavy industry, marine, mining, utilities and manufacturing. The SDCS‑FEX‑2 board is part of ABB’s extensive modular control ecosystem, reflecting the brand’s commitment to reliability, serviceability and performance.

Product Series

Series Name: DCS Drive Control / Field‑Excitation Module Series
This series covers modular boards for drive systems, including control logic (CON series), communication/adapter boards (COM/BAB series), I/O and measurement modules (IOB/AMC series), and field/excitation modules (FEX/FEP series). The FEX‑2 belongs to the field‑excitation subset, dedicated to managing the rotor excitation circuits of DC motors or generators within the DCS rack architecture.

Related or Same‑Series Models (5 Recommended)

Popular ABB Models (5 Recommended from the Brand)