Product Core Brief

• Model: FC-TSHART-1620M
• Brand: Honeywell Safety Solutions
• Series: FSC / Safety Manager SIL Safety Instrumented System Platform
• Core Function: DIN rail field termination assembly that conditions 4–20mA HART transmitter signals, converts to 0–4V, and provides dedicated ports for external HART multiplexers
• Product Type: HART-Capable Safety Analog Input FTA (Field Termination Assembly)
• Key Specs: 16 channels split 2×8 groups | 250Ω precision shunts | Per-channel 315mAT slow-blow fuses | MTL/P+F HART multiplexer expansion portsNote: Discontinued end-of-life SIS hardware, stocked exclusively as unopened New Surplus inventory; conformal coated PCB designated by FC prefix.

Key Technical Specifications

• Compatible Rack IOM: FC-SAI-1620M 16-channel SIL3 safety analog input module
• Channel Layout: 16 isolated analog channels split into two independent 8-channel banks with shared ground reference
• Supported Field Signals: 0–20mA / 4–20mA two-wire safety transmitters
• Signal Conversion: Integrated 250Ω precision resistors convert field current to 0–4V input for the paired safety IOM
• Overcurrent Protection: 315mAT slow-blow fuse assigned to every individual channel
• HART Interface: Dedicated header connectors for direct wiring to MTL and Pepperl+Fuchs HART multiplexer hardware
• Interconnect Cable: SICC ribbon cable mates FTA to FC-SAI-1620M rack IOM
• Field Supply Range: 20–30VDC nominal 24VDC transmitter power; FTA unloaded draw ≤15mA
• Galvanic Group Isolation: Optical isolation between each 8-channel bank and the SIS rack bus
• Ambient Operating Temperature: -20°C minimum to +60°C maximum cabinet ambient
• Hazardous Location Approval: FM Class I Div 2 Groups A/B/C/D cabinet mounting certified
• PCB Protection: Full conformal coating to resist salt spray and corrosive refinery/offshore cabinet atmospheres
• Mount Standard: TS35 DIN rail snap-in mounting
• Physical Dimensions: 250mm L × 70mm W × 58mm D; net unit weight 0.36kg

Product Introduction

This termination base delivers all field-side signal conditioning required for HART-enabled safety transmitters on Safety Manager racks. It integrates shunt resistors, channel fusing, surge suppression, and dedicated multiplexer ports to eliminate external marshalling hardware for HART device diagnostics.Grouped 8-channel bank isolation restricts short-circuit faults to a single segment, maintaining partial gas, pressure, and temperature safety loop visibility during field wiring failures, a mandatory SIL3 fault coverage design requirement.

QA & Testing SOP (Transparency Building)

1. Incoming Inspection: Cross-reference serial barcodes against Honeywell OEM batch production logs; inspect PCB for coating delamination, cracked solder joints, bent SICC ribbon connector pins, and damaged terminal lugs; validate original factory anti-static packaging seal integrity.
2. Live Testing: Mated with spare FC-SAI-1620M on a bench Safety Manager rack powered by a Fluke 115 regulated 24VDC supply; run 24-hour cyclic 4–20mA ramp testing with simulated open-loop and short-circuit fault injection across all 16 channels, plus HART handshake validation with calibrated smart transmitters.
3. Electrical Testing: Megger insulation resistance test >10MΩ between each field channel and SICC ribbon bus pins; confirm each 315mAT fuse trips consistently above 25mA overcurrent threshold, and 250Ω shunt resistance stays within ±1% tolerance.
4. Firmware/Config Backup: No onboard programmable firmware storage; capture high-resolution photos of channel bank address jumpers and HART multiplexer header pinouts for field service reference before bench testing.
5. Final QC & Packaging: Attach serialized printed test pass tag; seal unit in foam-lined static-shielded bag to protect SICC edge connector pins during warehouse storage and transit.

Installation Pitfalls & Guide (Engineer to Engineer)

❗ Firmware Rev Compatibility Risk: Safety Manager R150 and older solver firmware lacks full HART device fault logging; upgrade rack logic solver firmware to R160 or newer before FTA swap to avoid unrecorded transmitter drift blind faults on SIL safety loops.❗ Jumper Configuration Loss: Capture high-res photos of 8-channel bank grouping jumpers on the removed old unit; misconfigured bank jumpers lock out entire groups of HART transmitters from safety logic scan tables.❗ Wiring Incompatibility: This assembly’s SICC ribbon pinout does not interchange with standard FC-TSAI-1620M non-HART FTAs; cross-substitution without full field harness retermination disables all HART diagnostic communication.❗ Loop Resistance Miscalculation: Combined field cable + transmitter resistance exceeding 650Ω collapses full-scale 20mA signals; install inline loop booster power supplies for detector runs longer than 750 meters.❗ ESD Component Damage Risk: Ungrounded technicians have destroyed HART filter ICs during rack IOM/FTA swap-outs; latent ESD damage creates intermittent loss of secondary variable data that surfaces after 3–5 weeks of continuous runtime.

4-step replacement guide:

1. Pre-install: Activate cabinet LOTO on 24VDC field transmitter power; secure grounded anti-static wrist strap to chassis DIN rail ground lug.
2. Removal: Document bank grouping jumper positions via photo; disconnect SICC ribbon cable from rack FC-SAI-1620M IOM, remove each field detector wire sequentially channel by channel from screw terminals, slide the unit off TS35 DIN rail.
3. Install: Mount new hardware to DIN rail, replicate all bank jumper settings from reference photos, reterminate field transmitter wiring to matching channel terminal blocks, fully seat and lock the SICC ribbon cable connector to the paired safety IOM.
4. Power-on Test: Restore rack and field power; open Safety Builder diagnostic screens to confirm zero active open/short loop faults, stable primary PV readings, and successful HART multi-variable retrieval from all connected smart safety transmitters.

FAQ (Frequently Asked Questions)

Q: Can this termination base operate in redundant SIL3 SIS fire/gas rack configurations?A: The hardware itself does not include dual mirrored signal buses for native channel redundancy. Redundant safety analog monitoring requires dual independent FC-SAI-1620M IOM + FC-TSHART-1620M FTA hardwired parallel to field transmitters; single FTA slots cannot deliver 1oo2 fault tolerance for SIL-rated critical reactor and distillation shutdown loops.Q: Does the assembly support hot-swapping of the paired FC-SAI-1620M IOM while the Safety Manager rack remains energized?A: The rack IOM card can be extracted from the live rack slot, but all external field transmitter wiring must be fully disconnected via LOTO before detaching the SICC ribbon cable from the base. Live field power disconnection induces voltage transients that damage the onboard HART filter and surge suppression networks on the PCB.Q: What warranty coverage applies to bench-tested surplus stocked units?A: All inventory units carry a 12-month functional warranty covering factory PCB, shunt resistor, terminal, and HART coupling circuit defects. Damage from field surge overload, misconfigured bank jumpers, or ungrounded ESD handling is excluded from all coverage terms.Q: Is there a direct drop-in modern replacement for this discontinued HART-enabled FTA hardware?A: Honeywell’s current-generation universal safety termination hardware supports HART transmitters, but full field harness retermination and Safety Builder gas hazard logic revalidation is mandatory; SICC ribbon pinout and HART multiplexer header routing do not match for unmodified direct swap.Q: What fault isolation do the independent per-channel fuses provide during field wiring shorts?A: Each channel uses an isolated slow-blow fuse; a shorted detector wire only disables one single measurement channel, leaving the remaining 15 safety analog input loops fully operational for critical hazard monitoring.Q: Can non-HART 4–20mA transmitters be wired to this FTA without disabling the HART headers?A: Yes. Non-smart transmitters operate normally without changes to base jumpers; unused HART multiplexer headers remain passive and do not introduce signal interference with standard analog measurement channels.Q: Can this FTA be paired with digital safety IOM hardware like FC-SDID series input modules?A: Not supported. The SICC ribbon pinout and onboard 250Ω shunt signal conditioning circuits are engineered exclusively for FC- analog safety IOM hardware. Mismatched digital IOM pairing produces unrecognized backplane bus device faults and permanent shunt circuit overload damage within minutes of power application.