Description
Triconex 3636T Redundant Relay Output Module
The Triconex 3636T is a 16-channel, non-triplicated, redundant relay output module designed for use within Tricon v9 through v11 Triple Modular Redundancy (TMR) safety instrumented systems. It provides galvanic isolation for interfacing safety systems with low-power field circuits, motor control centers (MCCs), or interposing relay racks. Utilizing a dual-drive circuit architecture configured in a 1-out-of-2 (1oo2) internal logic array, the 3636T balances de-energize-to-trip safety integrity with high system availability for critical interlock and shutdown loops.
Commercial and Availability Status
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Condition: New Original (Factory Sealed Surplus)
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Warranty: 12-Month Mechanical and Electrical Warranty
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Availability: Limited Stock Available
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Lead Time: Ships within 2 to 4 business days
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Pricing Note: Listed price is indicative and subject to market availability constraints. Contact our commercial sales division for a formal, line-item quote.
Technical Specifications
| Parameter | Specification / Value |
| Model Number | 3636T |
| Output Channels | 16 points, non-triplicated, redundant configuration |
| Relay Type | Normally Open (NO), simplex relay contacts |
| Maximum Voltage (AC) | 125 V AC |
| Maximum Voltage (DC) | 30 V DC |
| Current Rating (AC Load) | 2 A maximum per point (resistive) |
| Current Rating (DC Load) | 2 A maximum per point at 30 V DC |
| Minimum Contact Load | 10 mA at 5 V DC |
| Fusing | 2.5 A fast-acting per point (located on external termination) |
| Galvanic Isolation | 1,500 V AC (chassis to field loops) |
| Response Time | < 30 ms (command to contact state transition) |
| Module Diagnostic Indicators | PASS, FAULT, ACTIVE |
| Field Wiring Identification Code | Dark Blue |
| Approximate Shipping Weight | 2.1 kg (4.6 lbs) |
Circuit Architecture and Safety Performance
The 3636T differs from standard TMR digital output modules by utilizing electromechanical relay contacts rather than solid-state switches.
Internal 1oo2 Voting Array
While the upstream Main Processors execute 2oo3 voting logic, the 3636T processes output commands via a dual, parallel-series relay tree arrangement. Internally, each output point is driven by two independent primary relay stages wired to ensure that a failure of a single relay switch does not inadvertently trigger or prevent a trip condition.
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De-energize to Trip (Fail-Safe): In standard configuration, when the logic demands a safety trip, power to the relay coils is cut. The contacts drop open, interrupting the field loop current.
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Continuous Over-Current Protection: The module does not contain onboard field-replaceable fuses. Over-current protection must be established externally using a compatible Triconex External Termination Panel (ETP) fitted with 2.5 A fast-acting fuses on each line.
Engineering and Field Deployment Guidelines
1. Handling Inductive Loads
Electromechanical relays are susceptible to contact pitting and accelerated wear when switching inductive field components, such as solenoid valves or heavy contactor coils.
Critical Field Note: When controlling inductive loads, you must install external arc suppression networks across the field device terminals. Use an RC snubber network for AC-powered circuits, or a reverse-biased flyback diode for 24 V DC circuits to prevent back-EMF spikes from welding the 3636T contacts.
2. Hot-Swap Constraints
The 3636T allows online hot-swapping under live rack conditions. Before removing an active module, ensure that the adjacent slot contains an identical, configured module that has completed its synchronization cycle.
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Verify that the target module’s ACTIVE light is solid before withdrawing the degraded hardware.
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Do not force the module into the slot; ensure the physical keying alignment matches the dark blue color assignment on the high-density backplane connector.
3. Contact Resistance and Degradation Testing
Over extended operation, contact resistance within the physical relays can increase due to micro-arcing. During scheduled turnaround maintenance cycles, log the voltage drop across active channels under full load conditions. If the contact resistance exceeds 0.2 ohms on any single point, plan to cycle or hot-swap the module to avoid localized heating.
Frequently Asked Questions
Why is the 3636T classified as “non-triplicated” if it sits in a Tricon system?
The 3636T processes the triplicated output commands from the Main Processors, but the physical output path relies on dual electromechanical relays in a redundant 1oo2 matrix rather than three independent solid-state switches. This design accommodates higher voltage/current thresholds and complete galvanic isolation where electronic switches are unsuitable.
What causes a localized FAULT LED on a single channel while the main module PASS LED is green?
This anomaly typically indicates a status mismatch during the module’s automatic diagnostic loop testing. The internal logic senses that the physical relay armature did not move to the commanded state or that an internal coil drive circuit has opened. While the redundant parallel path may keep the field device powered, the module should be scheduled for replacement.
Can I mix AC and DC voltages on different channels of the same 3636T module?
No. The channels on the 3636T share common internal reference sectors depending on the specific External Termination Panel (ETP) used. Check your systematic loop diagrams and the OEM termination guide before introducing mixed voltage potentials to the same module block to avoid cross-talk or isolation breakdown.
