ICS Triplex T9851 Digital Output Termination Assembly

The ICS Triplex T9851, also cataloged as the T9851 Digital Output Termination Assembly, operates as a dedicated hardware component for field signal power distribution and current protection within AADvance T9000 safety systems.

Hardware Specifications

Triple Modular Redundant (TMR) Architecture & Galvanic Isolation

The T9851 digital output termination assembly incorporates dual field power distribution buses engineered for SIL3 emergency shutdown (ESD) applications. Physical circuit traces provide high galvanic isolation between field power loops and internal system backplane logic to prevent fault propagation. Redundant power feeds pass through dual 10 A over-current fuses, ensuring fail-safe state execution during single-source power line faults or short-circuit events on connected field actuators.

Frequently Asked Questions

Q: How is field supply redundancy implemented on the physical T9851 terminal block?

A: The termination assembly accepts two independent 24 VDC field power feeds, each protected by an individual, replaceable 10 A fuse to maintain output availability if one field supply fails.

Q: What safety integrity level (SIL) applications is the T9851 assembly specified for?

A: When integrated into an AADvance T9000 safety controller architecture, the module supports SIL3 safety instrumented functions (SIF), including emergency shutdown (ESD) and fire and gas protection circuits.

Q: Are output channels on the T9851 individual isolated or simplex configured?

A: The T9851 provides 8 simplex 24 VDC digital output channels designed to interface directly with field load devices such as solenoids, relays, and status indicators.

Field Installation Guidelines

• Secure the termination assembly directly to a standard 35 mm DIN rail inside a protected NEMA or IP-rated enclosure, ensuring adequate clearance for field cable wiring trays.

• Terminate dual 24 VDC field power sources using copper wiring rated for 75 deg C, applying recommended terminal screw torque to maintain tight electrical contact under vibration.

• Route digital output load conductors in separate wire channels away from high-voltage AC power lines to avoid capacitive signal noise coupling.

• Connect a dedicated chassis grounding conductor from the assembly earth terminal directly to the main enclosure earth bus bar to establish surge voltage protection and reliable noise rejection.