Product Overview

In the field of functional safety, “output equals execution”—once the safety logic determines that a hazard has occurred, the output module must reliably trigger the final element (such as shutting off fuel, stopping pumps, or relieving pressure). The Triconex 3511 is the core hardware component for this critical function. As a standard digital output card in the Tricon TMR (Triple Modular Redundant) architecture, it is not simply a relay board, but an intelligent safety output unit integrating three independent processing channels, a voting mechanism, and fault diagnostics.

In several LNG receiving terminal and refinery SIS projects I’ve participated in, the fail-safe behavior of the 3511 module directly determined the consequences of an accident. For example, in a high-pressure reactor over-temperature interlock, after the Tricon main processor issues a trip command via a two-out-of-three voting mechanism, the three independent output channels within the 3511 module simultaneously energize their respective relay coils; the common contact only switches when at least two channels successfully actuate. If a channel fails due to a coil open circuit or contact welding, the system immediately detects the anomaly through a health check pulse and reports “Channel X Fault” in the Tricon’s Diagnostic Monitor software, while maintaining the safety output—this is precisely the high diagnostic coverage (>99%) and safe failure fraction (SFF) required by SIL 3. Technical Specifications

Model: 3511

Manufacturer: Triconex (Schneider Electric)

Applicable Systems: Tricon v10/v11/Triconex Trident (Backplane compatibility needs to be confirmed)

Number of Channels: 16 independent digital outputs

Output Type: Mechanical relay (Form C/SPDT: 1 normally open + 1 normally closed)

Contact Material: AgCdO or AgSnO₂ (arc-resistant, long lifespan)

Rated Load:

2 A 250 VAC (resistive)

1 A 125 VDC (inductive)

Maximum Switching Power: 60 W DC/125 VA AC

Electrical Life: ≥100,000 cycles (rated load)

Response Time: <10 ms (typical)

Isolation:

Channel-to-channel: Independent relays, physical isolation

Field side vs. system side: 2500 VAC (1 minute)

Safety Certifications:

IEC 61508 SIL 3 (TÜV Rheinland)

IEC 61511 (Process Industry SIS)

IEEE 603 ​​(Nuclear grade version optional)

Front Panel Indicators:

Green ACTIVE LED (module online)

Yellow FAULT LED (channel or communication fault)

Green OUTPUT LED per channel (relay energized status)

Mounting Method: Plugs into Tricon main chassis (e.g., 4328/4329)

Operating Temperature: 0°C to +60°C

Key Features and Benefits

✅ Native TMR architecture support: Triple output channels + voting, meeting SIL 3 requirements

✅ Forced-Guided Contacts: Ensures mechanical linkage of NO/NC contacts, supporting safety feedback

✅ Online Diagnostics: Thousands of health pulse checks per second for early fault warning

✅ No single point of failure: Failure of any single channel does not affect overall safety function output

✅ Plug-and-play: Hardware address automatically recognized by slot, no jumpers or configuration required

The Triconex 3511 isn’t just an output card—it’s a certified safety actuator. By combining triple redundancy, forced-guided relays, and continuous diagnostics, it ensures that when the system says “trip,” the valve will trip. closes. Every time. No exceptions.

Application Areas

The 3511 is almost exclusively used in high-integrity safety instrumented systems (SIS):

Oil and Gas: Wellhead emergency shutdown (ESD), pipeline compressor protection, LNG leak interlock

Chemical and Pharmaceutical: Reactor temperature/pressure over-limit shutdown, toxic gas release suppression

Power and Energy: Gas turbine burner management (BMS), boiler furnace pressure protection

Industrial Gases: Air separation unit oxygen concentration high interlock, storage tank overpressure relief

Legacy SIS Upgrades: Replacing earlier 3501/3503 modules to improve diagnostic capabilities

Integration and Maintenance Considerations

Operating the Triconex 3511 requires strict adherence to functional safety procedures:

⚠️ Authorized personnel only: Must receive Triconex safety training and be certified.

🔌 Enter Maintenance Mode before replacement: Use TriStation 1131 software to place the system in a safe state.

🧪 Perform Output Test: After replacement, verify the operation and feedback signals of each relay.

🔍 Regularly inspect contacts: For high-frequency operation circuits, it is recommended to measure contact resistance annually (should be <100 mΩ).

📜 Maintain traceable records: Retain module serial numbers and test reports to meet ISO 13849/IEC 61511 audit requirements.

Lifecycle and Procurement Recommendations

The Triconex 3511 is currently in “Long-Term Support,” and Schneider Electric has explicitly committed to providing spare parts and software support for the Tricon system until at least 2035.

Shenzhen Changxin, as a Schneider Electric automation ecosystem partner, holds inventory of original Triconex 3511 modules. All units meet the following criteria:

Sourced from Schneider authorized channels or factory-certified decommissioned units

Includes original labels, serial numbers, and compatibility confirmation (v10/v11)

Fully functionally tested: 16-channel relay operation, TMR voting simulation, LED indication, insulation testing

Provides 12-month warranty and basic TriStation 1131 technical support

Important Note: The use of non-original or generic relays is strictly prohibited! The 3511’s TMR logic, diagnostic algorithms, and certification status are an integral part of the SIL 3 system. In safety-critical systems, output reliability is non-negotiable. The Triconex 3511 delivers certified, triple-redundant assurance—so your final elements respond exactly when lives and assets depend on it.

Choose Shenzhen Changxin for peace of mind and worry-free after-sales service. Large stock available, same-day SF Express shipping!!!