Fuji Electric NB1 Series Modules: NB1-E24X-AC

Technical Dossier

Product Details And Specifications

Fuji Electric NB1 Series: Comprehensive Module Range and Technical Overview

The Fuji Electric NB1 Series is a compact, modular programmable logic controller platform deployed across heavy industrial sectors including petrochemical processing, power generation, water treatment, and discrete manufacturing. The NB1 architecture is characterized by its DIN-rail-mountable form factor, integrated AC/DC power input variants, and a structured I/O expansion bus that supports both digital and analog signal types. In global heavy industry, the NB1 Series occupies the mid-range control tier — positioned above relay-based systems and below full DCS platforms — making it a standard choice for machine-level automation and process sequencing in facilities where compact footprint and deterministic scan times are critical operational requirements.

The NB1-E24X-AC specifically is an AC-powered digital input/output expansion unit within the NB1 family, providing 24-point mixed I/O capacity suitable for interfacing with field devices including sensors, actuators, solenoid valves, and motor starters in 100–240V AC supply environments.

The Evolution of NB1 Series Architecture

The Fuji Electric NB1 Series was introduced as part of Fuji's broader MICREX-SX and compact PLC product strategy, targeting OEM machine builders and system integrators requiring a cost-effective, space-efficient controller with deterministic I/O response. Early NB1 units featured fixed I/O configurations with onboard AC power supply inputs, targeting single-phase industrial environments. Subsequent revisions introduced modular expansion capability, allowing base units to be extended with discrete digital I/O modules, analog input/output modules, and communication adapters.

The NB1 platform's communication architecture evolved from proprietary RS-232/RS-485 serial links to support Modbus RTU and, in later variants, Ethernet-based protocols for SCADA integration. Compatibility considerations are significant for maintenance engineers: early NB1 base units use a specific backplane bus connector standard that is not forward-compatible with Fuji's later MICREX-F or SPH series. Replacement modules must match the original series designation precisely. As the NB1 Series has entered its mature/end-of-life phase, sourcing genuine replacement modules from authorized distributors and specialist spare parts suppliers is the primary maintenance strategy for installed base continuity.

NB1 Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified models within the Fuji Electric NB1 Series. Models are classified by functional category.

Base CPU / Controller Units

• NB1-E24X-AC: 24-point digital I/O expansion unit, AC power input, mixed DI/DO configuration
• NB1-E16X-AC: 16-point digital I/O expansion, AC supply, compact DIN-rail mount
• NB1-E16X-DC: 16-point digital I/O expansion, 24V DC supply variant
• NB1-E24X-DC: 24-point digital I/O expansion, 24V DC supply, sink/source configurable

Digital Input (DI) Modules

• NB1-DI16: 16-channel digital input module, 24V DC, sink type
• NB1-DI32: 32-channel digital input module, high-density I/O for large-scale sequencing
• NB1-DI16-AC: 16-channel digital input, 100–240V AC input signal compatible

Digital Output (DO) Modules

• NB1-DO16T: 16-channel transistor output module, 24V DC, NPN open-collector
• NB1-DO16R: 16-channel relay output module, 250V AC / 30V DC contact rating
• NB1-DO32T: 32-channel transistor output, high-density discrete control

Analog Input/Output (AI/AO) Modules

• NB1-AI4: 4-channel analog input module, 4–20mA / 0–10V selectable, 12-bit resolution
• NB1-AI8: 8-channel analog input, suitable for multi-loop process variable monitoring
• NB1-AO4: 4-channel analog output module, 4–20mA current output for control valve positioning

Communication Adapter Modules

• NB1-RS485: RS-485 serial communication adapter, Modbus RTU master/slave support
• NB1-ETH: Ethernet communication module, 10/100 Mbps, Modbus TCP protocol
• NB1-PROFIBUS: PROFIBUS-DP slave adapter for integration into Siemens or ABB DCS environments

Power Supply Units

• NB1-PA: AC power supply module, 100–240V AC input, 24V DC regulated output for I/O bus
• NB1-PD: DC power supply module, 24V DC input, internal bus power regulation

Sourcing Hard-to-Find & Obsolete NB1 Series Parts

The Fuji Electric NB1 Series has reached end-of-active-production status in most regional markets. Fuji Electric's official channel no longer stocks the full range of NB1 expansion modules, communication adapters, and power supply units as new inventory. For facilities operating NB1-based control systems — particularly in chemical processing, water/wastewater, and legacy discrete manufacturing — the primary risk is unplanned downtime caused by module failure without available replacement stock.

DriveKNMS maintains a dedicated inventory of NB1 Series spare parts sourced through authorized secondary market channels, including tested pull units, new-old-stock (NOS) modules, and factory-refurbished assemblies. Each unit is individually tested against Fuji Electric's original functional specifications prior to dispatch. DriveKNMS provides lifecycle extension support for the NB1 platform, including cross-reference assistance for identifying compatible replacement modules where direct equivalents are unavailable, and technical consultation for customers evaluating migration paths to current Fuji Electric platforms.

Quality Control for the NB1 Series Range

NB1 Series modules present specific quality verification challenges due to their integrated backplane bus connectors, onboard EEPROM configuration storage, and mixed AC/DC power input circuitry. DriveKNMS applies the following test protocol to all NB1 units processed through its facility:

• Visual and mechanical inspection: Connector pin integrity, PCB condition, housing crack assessment, and label verification against Fuji Electric part number databases.
• Power-on functional test: Each module is energized at rated supply voltage (AC or DC as applicable) and monitored for correct power-on LED indication and absence of fault codes.
• I/O channel verification: All digital input and output channels are individually stimulated and verified using a dedicated NB1-compatible test rig. Analog modules are tested for linearity and offset error within Fuji Electric's published tolerance bands.
• Communication bus test: Communication adapter modules are tested for correct protocol handshake, data frame integrity, and error-free transmission over RS-485 and Ethernet interfaces as applicable.
• Burn-in cycle: Selected modules undergo a 24-hour powered burn-in cycle to screen for early-life component failures prior to shipment.
• Documentation: Each dispatched unit is accompanied by a test report referencing the specific NB1 part number, serial number (where present), and test results.

For NB1 Series parts inquiries, availability checks, and technical consultation:

• Email: [email protected]
• WhatsApp: +86 18359293191
• Website: driveknms.com