The ABB NTU-7C2, serves as the primary NTU-7C2 Termination Unit utilized to execute field signal routing and isolation across Bailey Infi 90 platforms.

Hardware Variant Configuration

The NTU-7C2 isolated interface module operates as a field termination chassis within the Bailey Infi 90 I/O subsystem. The base designation NTU defines the termination unit architecture for field wiring interface, while the suffix -7C2 denotes the specific isolated channel layout supporting multi-channel 4-20 mA analog loops with bi-directional surge suppression.

Technical Specifications

Fieldbus Integration and Channel Density

Designed for optimal I/O density scaling, the unit maintains signal integrity between field devices and host controllers across backplane bus communication velocity links. Integrated 600 W bi-directional surge suppression and 1.5 kV AC terminal-to-earth isolation safeguard upstream control electronics without introducing firmware flash compatibility delays or channel degradation.

Delivery Package Components

• 1 x ABB NTU-7C2 I/O Controller Termination Unit

Cabinet Mounting and Wiring Instructions

• Strip conductor insulation to 7 mm before inserting into terminals to ensure full clamp engagement.
• Tighten terminal screws to a torque spec of 0.5 to 0.6 Nm using an insulated torque screwdriver.
• Secure field wiring shields to the enclosure grounding bar, maintaining single-point earthing per loop.
• Ensure 50 mm clearance above and below the terminal block for adequate air convection cooling.

Technical FAQ

• What maximum wire gauge does the NTU-7C2 screw terminal accept?

  The screw terminal block accommodates solid or stranded conductors ranging from 0.2 to 4 mm2.

• What level of electrical isolation is provided by the termination unit?

  The module provides 1.5 kV AC dielectric isolation measured between field terminals and earth ground.

• What is the maximum continuous current capacity per terminal point?

  Each individual terminal is rated to handle a continuous current load up to 8 A.

• How does the integrated surge protection operate on 4-20 mA loops?

  The unit utilizes 600 W bi-directional suppression elements to clamp transient voltage spikes on field lines.

• What is the contact resistance across the terminal connections?

  The terminal contact assembly maintains an internal contact resistance of less than 3 mOhm.

• Can the NTU-7C2 be operated in ambient temperatures below freezing?

  Yes, the hardware is rated for continuous operation down to -20 deg C.

• Does the unit draw active power from the backplane power supply?

  No, the unit functions as a passive interface termination assembly and draws no internal operating power.

• What insulation voltage rating applies to field signal wiring?

  The terminal assembly features an operating voltage insulation rating of 250 V AC.