Allen‑Bradley 1794‑TB3 FLEX I/O Terminal Base Unit 3‑Wire Screw Clamp

3‑wire screw‑clamp terminal base for FLEX I/O systems, providing 0‑15 I/O terminals, common and power supply connections, and DIN rail mounting for distributed I/O architectures.

The Allen‑Bradley 1794‑TB3 is a terminal base unit in the FLEX I/O platform, designed to host analog and digital I/O modules in distributed control systems. It provides termination points for field wiring and power supply devices, supporting daisy‑chain power distribution and backplane communication. Used in FLEX I/O distributed I/O systems with terminal bases, I/O modules, and communication adapters.

Applications:

• Distributed I/O system installation

• Process manufacturing (chemical, pharmaceutical, food & beverage)

• Discrete manufacturing (automotive assembly, packaging, material handling)

• Infrastructure control (water treatment, HVAC, building automation)

• Energy and utilities (power generation, substation control)

Key Features:

• 3‑wire screw‑clamp terminal base (three terminal strips)

• 16 I/O terminals (0‑15) for field device wiring

• 18 common terminals and 18 voltage supply terminals (16‑33 common, 34‑51 +V)

• 640 mA @ 5V DC backplane current draw

• 10A max current rating, 125V AC/DC continuous isolation voltage

• DIN rail mounting (35 mm), supports panel mounting as well

• Supports Removal and Insertion Under Power (RIUP)

• Daisy‑chain power connections from terminal base to adjacent base

• Screw torque: 0.56‑0.79 Nm (5‑7 lb‑in)

Technical Specifications:

• Catalog number: 1794‑TB3

• Terminal type: Screw clamp (three terminal strips)

• I/O terminals: 16 (positions 0‑15)

• Common terminals: 18 (positions 16‑33)

• Voltage supply terminals: 18 (positions 34‑51)

• Wire range: 14‑22 AWG (2.5‑0.5 mm²)

• Screw torque: 0.56‑0.79 Nm (5‑7 lb‑in)

• Backplane current: 640 mA @ 5V DC

• Voltage rating: 125V AC/DC continuous, 24/120V AC/DC

• Current rating: 10A max

• Isolation: 125V continuous (basic insulation)

• Mounting: DIN rail (35 mm) or panel mount

• Dimensions: 94 × 94 × 69 mm (3.7 × 3.7 × 2.7 in)

• Operating temperature: 0°C to 55°C

• Certifications: UL, cUL, CE, RCM

System Integration:

• I/O System: FLEX I/O 1794 series (terminal base + I/O modules + adapter)

• Communication Adapters: 1794‑AENT (EtherNet/IP), 1794‑ACN(R) (ControlNet), 1794‑ASB (Remote I/O)

• Compatible I/O Modules: 1794‑IB16 (24V DC input), 1794‑OB16 (24V DC output), 1794‑IA16 (120V AC input), 1794‑IE8 (analog input), 1794‑IRT8 (RTD/thermocouple)

• Power Distribution: Daisy‑chain power from terminal base; also pairs with 1794‑TB3K (conformal coated), 1794‑TB3S (spring clamp alternative)

Related Products:

• Communication Adapter: 1794‑AENTR FLEX I/O EtherNet/IP Adapter – network connection

• Digital Input Module: 1794‑IB16 24V DC Input Module – I/O expansion

• Digital Output Module: 1794‑OB16 24V DC Output Module – output pairing

• Analog Input Module: 1794‑IE12 Analog Input Module – process signals

• Spring Clamp Alternative: 1794‑TB3S – faster tool‑free wiring

• Conformal Coated Version: 1794‑TB3K – harsh environment applications

PLC ERA is an independent industrial automation distributor. Products are sourced from established supply channels and inspected before shipment. International shipping available.