Yokogawa NFTB Series Terminal Blocks: NFTB5S-00 S2

Technical Dossier

Product Details And Specifications

Yokogawa NFTB Series: Comprehensive Module Range and Technical Overview

The Yokogawa NFTB series of pressure clamp terminal blocks is a core field-wiring interface component deployed across Yokogawa's CENTUM VP and CENTUM CS 3000 distributed control systems (DCS). These terminal blocks serve as the physical connection layer between field instrumentation — including transmitters, actuators, and sensors — and the I/O modules housed in the DCS cabinet. The NFTB series is installed in continuous-process industries where signal integrity, mechanical reliability, and long-term availability are non-negotiable: petroleum refining, petrochemical complexes, LNG terminals, nuclear power generation, pulp and paper mills, and large-scale chemical manufacturing. The pressure clamp (screwless spring-clamp) termination mechanism eliminates the risk of conductor loosening due to vibration or thermal cycling, making the NFTB series the preferred termination standard in high-vibration and high-temperature plant environments. The NFTB5S-00 S2 is a specific variant within this series, designed for use with standard signal wiring in CENTUM VP field terminal assemblies.

The Evolution of NFTB Series Architecture

Yokogawa's field terminal architecture has evolved in parallel with the CENTUM platform generations. Early CENTUM XL and CENTUM-V systems used screw-type terminal blocks with separate marshalling cabinets, requiring extensive manual wiring and periodic re-torquing. With the introduction of CENTUM CS 1000 and CS 3000 in the late 1990s and early 2000s, Yokogawa standardized on the NFTB pressure clamp format to reduce installation time and improve long-term connection reliability. The NFTB series was designed to be backward-compatible across cabinet generations, allowing plants to upgrade I/O modules without replacing the entire field wiring infrastructure. With the release of CENTUM VP (introduced circa 2008 and continuously updated through VP R6), the NFTB series was retained as the standard termination interface, ensuring that installed field wiring from CS 3000 installations could be migrated to VP hardware with minimal rewiring. This architectural continuity is a deliberate Yokogawa design philosophy that reduces migration cost and plant downtime. As CENTUM CS 3000 has entered its end-of-active-support phase, the NFTB series components associated with it are increasingly sourced through specialist spare parts distributors rather than direct OEM channels. Plants operating legacy CS 3000 systems must maintain an adequate stock of NFTB terminal blocks to support ongoing maintenance and I/O card replacement activities.

NFTB Series Full Catalog & Functionalities (SKU List)

The following SKUs represent the documented NFTB series terminal block variants used across Yokogawa CENTUM VP and CS 3000 field terminal assemblies. Each entry reflects a specific wiring configuration, signal type, or cabinet mounting variant.

NFTB5S-00 S2: Pressure clamp terminal block, 5-terminal, standard signal wiring, S2 revision for CENTUM VP/CS 3000 FTB assemblies.
NFTB5S-00 S1: Pressure clamp terminal block, 5-terminal, S1 revision; earlier production variant, functionally equivalent to S2 in most applications.
NFTB5D-00: Pressure clamp terminal block, 5-terminal, dual-row configuration for higher-density wiring applications.
NFTB10S-00: 10-terminal pressure clamp block for extended I/O channel groupings within a single terminal assembly.
NFTB10D-00: 10-terminal dual-row variant; used in marshalling configurations requiring higher conductor count per assembly.
NFTB5S-01: 5-terminal pressure clamp block with integrated fuse holder; used on powered field circuits requiring overcurrent protection at the termination point.
NFTB5S-02: 5-terminal block with disconnect link; allows individual circuit isolation without disturbing adjacent wiring.
NFTB5S-03: 5-terminal block with test point access; supports in-service loop testing without disconnecting field wiring.
NFTB5S-04: 5-terminal block with integrated diode; used on intrinsically safe (IS) circuits requiring passive barrier integration at the terminal level.
NFTB5S-05: 5-terminal block with ground bus connection; used for shield drain wire termination and cabinet grounding continuity.
NFTB10S-01: 10-terminal block with fuse holders on alternate terminals; used for mixed powered/unpowered signal groupings.
NFTB10S-02: 10-terminal block with disconnect links; supports selective circuit isolation in high-density I/O panels.
NFTB5D-01: Dual-row 5-terminal block with fuse holders; compact format for space-constrained cabinet installations.
NFTB5D-02: Dual-row 5-terminal block with disconnect links; used in retrofit projects where original cabinet space is limited.
NFTB-END: End bracket/stop plate for NFTB series terminal block assemblies; required at each end of a terminal block row to maintain mechanical alignment and prevent lateral movement.
NFTB-BRIDGE: Jumper bridge connector for NFTB series; used to create common bus connections across adjacent terminal blocks without additional wiring.
NFTB-MARKER: Identification marker strip compatible with NFTB series; used for circuit labeling per IEC 60445 terminal marking standards.

Sourcing Hard-to-Find & Obsolete NFTB Series Parts

As Yokogawa CENTUM CS 3000 has transitioned from active production to a maintenance-only lifecycle, OEM availability of NFTB series terminal blocks through standard distribution channels has become inconsistent. Lead times for new OEM stock can extend to 16–26 weeks for certain variants, and some S1-revision components are no longer manufactured. DriveKNMS maintains a dedicated inventory of NFTB series terminal blocks sourced from decommissioned plant equipment, authorized surplus channels, and long-term storage stock. All components are stored in climate-controlled conditions to prevent insulation degradation and contact oxidation. For plants operating CENTUM CS 3000 or early CENTUM VP installations, DriveKNMS provides lifecycle extension support including: bulk supply of NFTB terminal blocks for scheduled turnaround maintenance, emergency same-day dispatch for unplanned I/O failures, cross-reference verification between S1 and S2 revision variants, and documentation support for maintenance records and as-built drawing updates. Customers operating multiple process units with shared DCS infrastructure are encouraged to submit consolidated bill-of-materials (BOM) requests to optimize sourcing cost and lead time.

Quality Control for the NFTB Series Range

Terminal block components present specific quality verification challenges that differ from active electronic modules. For the NFTB series, DriveKNMS applies the following inspection protocol to all stock prior to dispatch. Visual inspection covers the pressure clamp spring mechanism for fatigue, deformation, or corrosion; the insulation body for cracking, discoloration, or UV degradation; and the conductor entry ports for debris or prior-use deformation. Mechanical testing verifies that the clamp actuation tool slot is undamaged and that the spring returns to full clamping force after actuation. Electrical testing confirms continuity across each terminal position and insulation resistance between adjacent terminals at 500 VDC per IEC 60664 requirements. For NFTB variants with integrated fuse holders (NFTB5S-01, NFTB10S-01, NFTB5D-01), fuse clip contact force and continuity are verified independently. Components that do not meet these criteria are quarantined and not dispatched. Each shipment is accompanied by an inspection record identifying the lot, test date, and technician reference.