SNB10D-225/CU2T Yokogawa SNB10D Safety Node Unit, Dual-Redundant AC

Product Overview

The SNB10D-225/CU2T is a Yokogawa SNB10D Safety Node Unit. It is a rack-mountable node for safety control systems. The unit carries a dual-redundant power supply and a software license for node expansion (R3). It ships with a Connector Unit with Terminator for the ESB Bus.

This node connects field I/O modules to a safety control unit through the ESB bus. Two SSB401 ESB bus interface modules sit inside the unit. Two power supply modules feed the I/O modules. The design supports up to 13 safety node units on one safety control unit when you use the SEC402 coupler.

• Core role: extends safety I/O capacity on an ESB bus network.
• Key strength: redundant power keeps the node alive if one supply fails.
• Best fit: process safety systems that need high node counts and wide temperature tolerance.

Technical Specifications

• Brand: Yokogawa
• Model: SNB10D-225/CU2T
• Series: SNB10D Safety Node Unit
• Module type: rack-mount safety node unit with connector unit
• Power supply: 220 to 240 V AC, 50/60 Hz
• Power consumption: 230 VA at 220 to 240 V AC
• Redundancy: dual-redundant power supply
• License: software license for node expansion (R3)
• Option code: CU2T connector unit with terminator for ESB Bus (part number S9343FA)
• Mounting: rack mount with four M5 screws and insulation bushes
• Weight: approx. 5.9 kg
• Operating temperature range: -20 to 70 °C
• Environmental tolerance: ISA Standard G3, no explosion protection
• Power terminal: M4 screws

Measurement and signal performance depend on the I/O modules you install. The node itself sets no range, linearity, or resolution figures. Choose I/O modules that match your measurement range, frequency response, sensitivity, linearity, and resolution needs. The node supplies the power, bus link, and slot space those modules require.

• Interference resistance: the CU2T terminator closes the ESB bus and limits signal reflection.
• Supply options in the family: 100 to 120 V AC (200 VA), 220 to 240 V AC (230 VA), or 24 V DC (5.5 A).
• Node count limits: up to 13 nodes with the SEC402 coupler; up to 9 nodes with the SEC401 coupler.

Suffix Code Tree

• SNB10D base safety node unit, rack mountable
  • -2 suffix code 1: dual-redundant power supply with software license for node expansion (R3)
    • 2 suffix code 2: 220 to 240 V AC power supply
      • 5 suffix code 3: ISA Standard G3 and temperature (-20 to 70 °C), no explosion protection
        • /CU2T option code: connector unit with terminator for ESB Bus (S9343FA)

Compatibility Notes

• Works with S2SC70S, S2SC70D, SSC60S, and SSC60D safety control units.
• Uses the SEC402 ESB bus coupler for up to 13 nodes.
• Uses the SEC401 ESB bus coupler for up to 9 nodes.
• Holds two SSB401 ESB bus interface modules and two power supply modules.
• I/O module count and slot position follow the Node Unit Mounting Restrictions in GS 32P06K60-01EN.

Installation Guide

• Mount the unit in a rack with four M5 screws.
• Fit the supplied insulation bushes before you tighten the screws.
• Tighten the power wires on the M4 terminals.
• Check the supply voltage against the suffix code before power-on.
• Keep the rack within -20 to 70 °C.
• Follow the slot rules for I/O modules in the node unit manual.
• Fit the CU2T terminator at the bus end to keep the link stable.

Commissioning and Maintenance

• Redundant supplies let you swap one power module while the node runs.
• The terminator cuts bus faults and saves time on startup checks.
• Front access to modules keeps service work short.
• Log the node count per coupler. Stay under 13 (SEC402) or 9 (SEC401).
• Inspect M4 and M5 terminals at each planned shutdown.

Certification and Standards

• Built to ISA Standard G3 for rugged plant conditions.
• Rated for -20 to 70 °C operation.
• This version carries no explosion protection. Do not use it in hazardous areas.
• Confirm site approvals with Yokogawa before you order.

Packing List

• 1 x SNB10D-225/CU2T Safety Node Unit
• 1 x connector unit with terminator, S9343FA
• 4 x insulation bushes
• Documentation set

FAQ

Q: How many nodes can one safety control unit take?

A: Thirteen with the SEC402 coupler. Nine with the SEC401 coupler.

Q: Can I run the node on 120 V AC?

A: No. This suffix code needs 220 to 240 V AC. The family also offers a 100 to 120 V AC version and a 24 V DC version.

Q: What happens if one power module fails?

A: The second supply carries the load. The node keeps working while you replace the failed module.

Q: Do I need the CU2T terminator?

A: Yes, for a stable ESB bus link. It ships with this model, so keep it fitted.

Q: Does the node set measurement range or accuracy?

A: No. The I/O modules do. Pick modules that match your range, frequency response, and linearity targets.

Q: From experience, what causes most startup faults on this unit?

A: Loose M4 power terminals and a missing bus terminator. Check both first.

Q: From experience, how do teams plan node growth?

A: They count nodes per coupler before design freeze. This avoids a coupler swap late in the project.

Q: Is this unit rated for explosive areas?

A: No. Suffix code 5 means no explosion protection.