Product Introduction

The SDCS‑FEX‑31 (3ADT306800R1) is a high‑performance field‑exciter module designed for use within ABB’s DCS (Drive Control System) architecture. It is specifically developed to provide controlled excitation current for synchronous machines or DC drives, integrated into converter cabinets. The “FEX‑31” variant signifies an improved version of the excitation board family, offering higher current capability, improved control loops, and advanced monitoring compared to earlier models.

This module is typically mounted inside a drive rack alongside other control and power modules (e.g., CON and POW series). It receives instructions from the drive logic board, monitors rotor field current, and adjusts the excitation supply accordingly to maintain stable machine operation under varying load and environmental conditions. The SDCS‑FEX‑31 is engineered for heavy‑industry, power‑generation, marine and process‑automation applications where reliability, precision and modular serviceability are required.

Technical Parameters

Product Application

The SDCS‑FEX‑31 module finds application in a wide variety of industrial contexts:

• Heavy‑duty DC drive systems (steel mills, mining conveyors) where rotor field excitation must be tightly regulated for stable operation.

• Synchronous machines (motors or generators) in power generation plants, where precise field current control is essential for stability, backup power supplies and grid compliance.

• Marine and offshore propulsion systems or auxiliary drive systems, where compact, service‑friendly excitation boards with high reliability are required in harsh environments.

• Process‐automation installations (chemical plants, pulp/paper, cement) that use modular drive racks and need excitation modules that integrate with other control and power modules.

• System upgrades or retrofits of legacy drives: replacing older excitation modules with the SDCS‑FEX‑31 improves serviceability, reduces maintenance downtime and enhances system diagnostics.

In each of these applications, the SDCS‑FEX‑31 serves as the critical interface between the drive’s logic/control modules and the machine’s field circuit, ensuring that the excitation current is maintained at the correct value under dynamic load conditions, thus enhancing machine performance, reliability and lifetime.

Product Advantages

• High Current & Voltage Capability – Supports up to ~500 V field voltage and ~40 A field current (depending on variant), making it suitable for large machine applications.

• Compact & Lightweight – With approximate weight of 0.32 kg and modest dimensions, it fits easily into standard drive racks, saving space and simplifying integration.

• Modular Design – Plug‑in architecture allows quick replacement, minimal downtime and simplified spare‑parts management.

• Improved Monitoring & Diagnostics – Built‑in sensors and logic feedback loops enable protection (overcurrent, field‑loss detection, temperature monitoring) and increased uptime.

• Seamless Integration – Designed to work within the ABB DCS modular ecosystem (CON, POW, BAB, FEX modules) promoting system compatibility and future upgrades.

• Reliability in Harsh Conditions – Industrial‑grade design supports wide temperature, humidity, and vibration environments typical of heavy‑industry installations.

• Reduced Total Cost of Ownership – By improving machine stability, lowering downtime and simplifying maintenance, the board contributes to improved lifecycle value.

• Future‑Proof Component – Being a newer variant in the FEX family (‑31) provides enhanced capabilities and supports evolving drive system demands.

Brand Overview

Brand: ABB
ABB is an industry‑leading provider of automation, drive systems and control modules. With decades of expertise in heavy industry, utilities, marine and manufacturing sectors, ABB delivers modular, robust hardware solutions. The SDCS‑FEX‑31 module exemplifies ABB’s commitment to precise control, reliability and long‑term serviceability in drive systems.

Product Series

Series Name: DCS Drive Control – Field‑Excitation Module Series
Within this series, ABB provides a range of boards including FEX (field exciter), FEP (excitation/protection), POW (power supply), CON (control logic), COM/BAB (communication modules). The “FEX” sub‑series is focused on excitation control for drives. The SDCS‑FEX‑31 sits at a higher‑capability tier within that sub‑series, offering enhanced performance compared to FEX‑1 or FEX‑2 models.

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