ABB SDCS-FEX-2A (3ADT311500R1) DCS Drives Field Exciter Power Supply Board

Description

The ABB SDCS-FEX-2A is an integrated single-phase field exciter and power supply circuit board engineered for internal mounting within armature converter modules. Functioning as a digital field exciter board, this module consists of an integrated power part and an onboard control processor section that links all internal components both electrically and mechanically.

The SDCS-FEX-2A is designed explicitly for installation inside ABB DCS converter modules of type C1, C2, and C3 alongside the electronic power supply board SDCS-POW-1, but is completely incompatible with C4 frame sizes. Operating with a wide single-phase rated input voltage range from 110V to 500V AC and a maximum current capacity of 16A, the 3ADT311500R1 uses a fully digital micro-controller layout to dynamically scale its active burden resistors, ensuring optimal signal resolution across an automated selection band between 3A and 16A.

Features

• Half-Controlled Bridge Rectification: Built using two internal diode-thyristor modules configured as a single-phase half-controlled bridge for high-efficiency motor field winding control.
• Onboard 80C198 Micro-controller: Features a dedicated embedded 80C198 micro-controller execution unit running localized PI firmware loop algorithms for direct current stabilization.
• Automated Burden Scaling: Dynamically selects internal hardware burden resistors depending on the motor nominal field parameters to maximize control accuracy.
• Integrated Surge Defenses: Equipped with dual Metal Oxide Varistors (MOVs) providing simultaneous transient voltage spike dampening across the AC input side and the inductive DC output circuits.

Applications

• Internal motor field excitation and closed-loop DC current regulation inside ABB DCS500 and DCS600 converter units.
• Heavy industrial drive lineups including variable-speed fan groups, crane hoist infrastructure, and heavy extrusion systems.

Technical Specifications

Empirical Engineering Insights

Alternative Models & Compatibility

The SDCS-FEX-2A module is specifically engineered for frame integration into DCS type C1, C2, and C3 converter modules. Do not attempt mechanical or electrical structural mounting inside larger type C4 converter bays, as the ventilation flows, structural sizing, and communication path cabling are completely non-interchangeable. The module retains a permanent fixed RS485 network routing identifier at Node Address 1, which requires strict configuration adherence on the accompanying master SDCS-CON-x board layout.

Application Pitfalls & Engineering Notes

During initialization, the onboard microcontroller depends on real-time parameter streaming from the main armature processor memory via flat cable X14. If an interruption occurs in the RS485 communication link or parameter table configuration values fail to deploy correctly, the field control software will fail to scale the internal burden resistors, causing zero-current tracking faults. Additionally, when testing output loop values via the terminal row X20:, external multi-meters must maintain an internal operational resistance greater than 1M Ohm to prevent short-circuit conditions or measuring errors.

Installation Guidelines