Triconex 3636R | 32-Channel TMR Relay Output Module for SIS/ESD – Field Service Notes

• Description

Hard-Numbers: Technical Specifications

• Protocol Support: Tricon TriBus backplane only; no external fieldbus
• Channel Count: 32 isolated, form-C relay outputs (non-commoned)
• Contact Rating: 250VAC / 30VDC, 2A resistive per channel; 2000VA max switching
• Isolation Rating: 1500VDC channel-to-backplane; 2.5kV RMS channel-to-channel
• Operating Temperature: -40°C to +85°C (storage -40°C to +85°C)
• Power Draw: 6W typical @5VDC backplane; 1.2A nominal
• Safety Rating: IEC61508 SIL3, UL Class I Div 2, ATEX Zone 2
• Dimensions: 177.8mm H × 101.6mm W × 228.6mm D
• Weight: 1.5kg (3.3lbs)
• Diagnostics: Per-channel coil/contact health, open/short detection

The Real-World Problem It Solves

Solid-state outputs can latch on fault and lack galvanic isolation; commoned relays risk cross-trip if one channel fails. This 3636R uses independent, isolated relays with TMR voting to eliminate both risks.Where you’ll typically find it:

• Refinery ESD racks driving shutdown valves and pump trip circuits
• Power plant BMS (burner management) fuel valve interlocks
• Offshore platform safety panels for critical isolation and depressurizationThis module keeps safety circuits fail-safe and fault-isolated, no single point of failure.

Hardware Architecture & Under-the-Hood Logic

It’s a TMR relay output card with three independent logic legs driving a single set of relays; backplane power only, no field power on board.

1. TriBus receives safety logic commands from Tricon controller to each of three TMR legs.
2. Each leg independently calculates output state; 2-out-of-3 vote triggers relay coil.
3. Each channel has a form-C relay with 1500V isolation; no common power or ground.
4. Onboard diagnostics monitor coil current and contact resistance; flag wear/fault per channel.
5. Hot-swap logic allows replacement without rack shutdown; relays default de-energized (fail-safe).

Triconex 3636R

Field Service Pitfalls: What Rookies Get Wrong

Mixing AC and DC Loads on the Same CardNew techs wire 24VDC solenoids and 120VAC valves to adjacent channels. Inductive kickback damages contacts and causes intermittent dropout.

• Field Rule: Group all AC loads on one card, DC on another; add MOVs across inductive loads.

Overloading Contacts with Inductive LoadsSpec sheet says 2A resistive; rookies run 2A inductive (solenoids, motors). Contact erosion happens in weeks, not years.

• Quick Fix: Derate inductive loads to 50% of resistive rating; use external contactors for >1A inductive.

Ignoring Relay Wear DiagnosticsTechs clear “contact resistance high” alarms without action. A worn contact can weld closed, preventing safety trip.

• Field Rule: Replace any channel with >500mΩ contact resistance during next outage; track cycle counts.

Commercial Availability & Pricing Note

Please note: The listed price is for reference only and is not binding. Final pricing and terms are subject to negotiation based on current market conditions and availability.