Primary Field Use: Driving 120VDC ESD solenoids, trip relays, and isolation valves in SIL3 safety systems.
Triconex 3623
Hard-Numbers: Technical Specifications
Protocol Support: TriBus backplane only; no external fieldbus
Channel Count: 16 supervised digital outputs, commoned negative
Output Voltage: 120VDC nominal; 90–155VDC operating, max 155VDC
Current Rating: 2A continuous per channel; 10A peak (10ms)
Isolation Rating: 1500VAC field-to-backplane; no channel-to-channel
Operating Temperature: -40°C to +70°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: 115mm H × 230mm W × 50mm D
Weight: 1.5kg (3.3lbs)
Diagnostics: Per-channel open/short, load presence, field power loss
The Real-World Problem It Solves
24VDC DO cards can’t drive high-power 120VDC solenoids; standard 120V relays lack diagnostics and wear fast. This 3623 delivers TMR voting plus per-channel load verification for 120VDC safety circuits.Where you’ll typically find it:
Power plant BMS fuel gas valve interlocks and turbine trip solenoids
Offshore F&G panels for 120VDC isolation valves and alarm beaconsThis module eliminates unmonitored 120V circuits and mechanical relay wear in high-power safety loops.
Hardware Architecture & Under-the-Hood Logic
It’s a TMR supervised 120VDC DO card with three independent logic legs, per-channel sense circuits, commoned outputs; backplane-powered, no field power on board.
TriBus receives safety logic commands from Tricon controller to each of three TMR legs.
Each leg independently calculates output state; 2-out-of-3 vote enables 120VDC output driver.
Each channel has voltage/current sense to verify load and wiring integrity.
Onboard diagnostics flag open/short/missing load per channel; pulse-test for hidden faults.
Hot-swap logic allows replacement without rack shutdown; outputs default off (fail-safe).
Triconex 3623
Field Service Pitfalls: What Rookies Get Wrong
Using 24VDC Loads on 120VDC ChannelsTechs mix 24V and 120V devices on the same 3623. Low-resistance 24V loads pull excess current, triggering false overcurrent and damaging output transistors.
Field Rule: Only wire 90–155VDC rated loads to 3623; segregate 24V loads to 3624/3674.
Ignoring Minimum Load RequirementsRookies leave channels unloaded or with <30mA loads. Diagnostics can’t verify circuit health, masking broken wires or open coils.
Quick Fix: Ensure each channel has ≥30mA load; add dummy resistors (3.9kΩ/10W) for unused channels.
Poor Shielding Causes Common-Mode NoiseTechs run 120VDC output cables parallel to AC power. Inductive coupling creates noise, triggering false “LOAD” alarms and intermittent dropout.
Field Rule: Separate 120VDC output wiring from AC cables by ≥30cm; shield all 3623 field cables and ground shield at cabinet only.
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.
