Triconex 3625C1 | Triple-Modular Redundant (TMR) Digital Output Module | Active Safety I/O for Critical Shutdown Systems
Triconex 3625C1 | Triple-Modular Redundant (TMR) Digital Output Module | Active Safety I/O for Critical Shutdown Systems - Image 2
Triconex 3625C1 | Triple-Modular Redundant (TMR) Digital Output Module | Active Safety I/O for Critical Shutdown Systems - Image 3
Triconex 3625C1 | Triple-Modular Redundant (TMR) Digital Output Module | Active Safety I/O for Critical Shutdown Systems - Image 4

Triconex 3625C1 | Triple-Modular Redundant (TMR) Digital Output Module | Active Safety I/O for Critical Shutdown Systems

  • Model: 3625C1
  • Brand: Triconex (a Schneider Electric brand)
  • Core Positioning: 16-channel digital output module with electromechanical relays for Tricon® safety instrumented systems (SIS)
  • Lifecycle Status: Active (in production and fully supported as part of the Tricon family)
  • Critical Function: Provides fail-safe, TMR-voted actuation signals to final control elements (e.g., solenoid valves, motor starters, alarms) in SIL3 applications
  • Typical Applications: Emergency shutdown (ESD), fire & gas systems, burner management (BMS), turbine trip circuits, and process isolation
Category: SKU: TRICONEX 3625C1

Description

Key Technical Specifications

  • Product Model: 3625C1
  • Manufacturer: Triconex / Schneider Electric
  • System Compatibility: Tricon v10.5+, Tricon CX, and compatible with legacy Tricon chassis (e.g., 4328A/4329A) with appropriate firmware
  • Output Type: Electromechanical relays (form C – SPDT contacts)
  • Number of Channels: 16 independent outputs
  • Contact Rating:
    • 2 A @ 30 VDC (resistive)
    • 2 A @ 28 VAC (resistive)
    • Not rated for inductive loads without external suppression
  • Voting Architecture: Triple-Modular Redundant (TMR) – each output driven by three independent lanes with hardware voting and diagnostic feedback
  • Fail-Safe Behavior: On loss of power or internal fault, all relays de-energize (fail-safe open), ensuring safe state per IEC 61508
  • Diagnostic Coverage: >99% – includes coil continuity, contact welding detection, and output mismatch monitoring
  • Hot-Swap Capable: Yes – can be replaced during system operation without shutdown
  • Status Indicators: Per-channel OK/FAULT LEDs; module-level PASS/FAIL indicators
  • Certifications: IEC 61508 SIL3, ANSI/ISA S84.01, CSA, ATEX (for hazardous area mounting when installed in certified enclosures)
  • Schneider Order Code Example: 3BSE043625R0001

System Role and Functional Safety Significance

The 3625C1 is a critical final element interface in Tricon-based Safety Instrumented Systems (SIS). It translates logic decisions from the Tricon main processors into physical actions—such as closing an emergency isolation valve, tripping a compressor, or activating a deluge system.

Because it uses electromechanical relays, it provides galvanic isolation between the safety controller and field devices, enhancing noise immunity and reducing common-cause failure risk. The TMR architecture ensures that even if one relay lane fails (e.g., due to contact welding), the other two can still enforce a safe state via 2-out-of-3 (2oo3) voting.

For example, in an offshore platform ESD system, the 3625C1 might drive solenoids on blowdown valves. If a gas leak is detected, the Tricon commands the relays to energize (or de-energize, depending on design), opening the valves to depressurize the system—while continuously verifying that the contacts moved as expected.

 

Reliability and Diagnostic Features

Key reliability advantages include:

  • Contact welding detection: Monitors for welded relay contacts that could prevent safe shutdown
  • Coil health monitoring: Detects open or shorted relay coils before failure occurs
  • Output verification: Compares commanded vs. actual relay state via internal feedback circuits
  • Automatic fault logging: All anomalies are timestamped and stored in the Tricon diagnostic buffer

These diagnostics are accessible via TriStation 1131, Triconex Diagnostic Manager, or integrated into EcoStruxure Asset Advisor for predictive maintenance.

Note: Due to relay wear, the 3625C1 has a finite mechanical life (~100,000 operations per channel). In high-cycle applications (e.g., frequent testing), consider using solid-state alternatives like the 3725N (if compatible with safety requirements).

TRICONEX 3625C1

TRICONEX 3625C1

Integration and Best Practices

  • Wiring: Use shielded cables with proper grounding; avoid running output wires parallel to high-voltage lines.
  • Load Protection: Always install external flyback diodes or RC snubbers for inductive loads (e.g., solenoids) to suppress voltage spikes.
  • Redundancy: For critical final elements, use dual 3625C1 modules in separate chassis with diverse routing (1oo2 or 2oo3 architectures).
  • Testing: Leverage Tricon’s Built-In Self-Test (BIST) and Partial Stroke Testing (PST) capabilities to validate output paths without full plant shutdown.

 

Lifecycle and Support Outlook

The 3625C1 remains an active, supported product within Schneider Electric’s Tricon portfolio. It is fully compatible with the latest Tricon CX systems and benefits from ongoing firmware updates, global spares availability, and long-term lifecycle commitments (>15 years outlook). This makes it a low-risk choice for new safety system deployments or upgrades from older Tricon I/O (e.g., 3503E, 3511C).

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