ABB SAFT Series Modules

Technical Dossier

Product Details And Specifications

ABB SAFT Series: Comprehensive Module Range and Technical Overview

The ABB SAFT (Scalar Adjustable Frequency Technology) series represents one of ABB's most widely deployed drive control board families across global heavy industry. Installed in chemical processing plants, oil refineries, nuclear power auxiliary systems, pulp and paper mills, and marine propulsion platforms, SAFT-series boards serve as the core intelligence layer within ABB's DCS/drive architecture. The SAFT 125 CHC (SAFT125CHC) — a chopper control board — is a representative component of this series, governing DC bus braking chopper circuits in medium-voltage drive systems. The SAFT series remains active in thousands of installed bases worldwide, making reliable spare parts sourcing a critical operational requirement for plant maintenance engineers and procurement teams.

The Evolution of SAFT Architecture

The SAFT series was introduced as part of ABB's drive control platform in the 1980s and 1990s, designed to interface with the ACS/DCS drive families including ACS 600, ACS 800, and earlier thyristor-based drive systems. Early SAFT boards used discrete analog signal processing for speed reference, current feedback, and fault logic. Mid-generation boards introduced ASIC-based gate pulse generation and digital communication interfaces compatible with DDCS (Distributed Drive Control System) fiber-optic protocols. Later revisions incorporated surface-mount technology (SMT) and improved EMC shielding. Many SAFT boards are now classified as End-of-Life (EOL) or Limited Availability by ABB, meaning OEM supply has been discontinued. However, the installed base remains extensive, and aftermarket sourcing, refurbishment, and functional testing are the primary maintenance pathways for plant operators committed to long-term system continuity without full drive replacement.

SAFT Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly referenced components within the ABB SAFT series. Each unit is described by its primary functional role within the drive or control system:

SAFT 125 CHC (SAFT125CHC): DC bus braking chopper control board for ACS/DCS drives.
SAFT 121 FIO (SAFT121FIO): Fiber-optic interface board for DDCS communication link.
SAFT 122 PAC (SAFT122PAC): Power supply and auxiliary control board, 24VDC regulated output.
SAFT 123 CON (SAFT123CON): Main control board for scalar frequency drive regulation.
SAFT 124 DIO (SAFT124DIO): Digital I/O expansion board, 16DI / 8DO configuration.
SAFT 126 AIO (SAFT126AIO): Analog I/O board, ±10V / 4–20mA signal conditioning.
SAFT 127 GDU (SAFT127GDU): Gate drive unit board for IGBT/thyristor firing circuits.
SAFT 128 PSU (SAFT128PSU): Internal switch-mode power supply board for control electronics.
SAFT 130 CPU (SAFT130CPU): Central processing unit board for drive parameter management.
SAFT 131 MEM (SAFT131MEM): Memory and parameter storage board, EEPROM-based.
SAFT 132 COM (SAFT132COM): Fieldbus communication adapter board (Profibus/Modbus).
SAFT 133 ENC (SAFT133ENC): Encoder interface board for closed-loop speed feedback.
SAFT 134 BRK (SAFT134BRK): Brake control logic board for mechanical brake sequencing.
SAFT 135 TMP (SAFT135TMP): Temperature monitoring board, PT100/NTC sensor inputs.
SAFT 136 SYN (SAFT136SYN): Synchronization board for multi-drive parallel operation.
SAFT 138 FLT (SAFT138FLT): Fault logging and diagnostic interface board.
SAFT 140 RLY (SAFT140RLY): Relay output expansion board, 8-channel, 250VAC rated.

Sourcing Hard-to-Find & Obsolete SAFT Series Parts

The majority of SAFT-series boards have been discontinued by ABB as the platform transitions to the ACS880 and ACS580 drive families with integrated control architecture. For plant operators running legacy ACS 600, ACS 800, or earlier thyristor drive systems, replacement boards are no longer available through standard OEM distribution channels. DriveKNMS maintains a dedicated inventory of refurbished, tested, and serialized SAFT-series boards sourced from decommissioned equipment, controlled factory surplus, and verified third-party channels. All units are inspected against original ABB schematic references. For critical applications — including continuous process industries where unplanned downtime carries significant financial and safety consequences — DriveKNMS offers advance exchange programs, emergency shipment, and long-term consignment stocking agreements. Procurement teams are encouraged to submit full BOM lists for cross-referencing against current stock.

Quality Control for the SAFT Range

SAFT-series boards present specific testing challenges due to their integration with high-voltage backplane buses, fiber-optic DDCS links, and proprietary ABB gate pulse timing circuits. DriveKNMS applies a multi-stage verification protocol to all SAFT inventory: (1) Visual inspection for component-level damage, corrosion, and PCB delamination; (2) In-circuit testing of power supply rails and reference voltages against ABB specification tolerances; (3) Functional simulation using drive emulation rigs that replicate DDCS communication handshake sequences; (4) Chopper and gate drive boards (including SAFT125CHC) undergo load-cycle testing under controlled resistive loads to verify switching accuracy and thermal stability; (5) Final burn-in at elevated ambient temperature for 24–48 hours prior to shipment. Each board is issued a test report and assigned a unique serialized tracking number.

For sourcing inquiries, technical cross-referencing, or emergency spare parts requests for ABB SAFT series modules: