2. Model Definition

51304493: Base model for 16-channel compact TC/RTD LLAI FTA

-200: Medium heavy reinforced industrial PCB grade

Medium-thick reinforced full-board conformal coating, excellent anti-humidity, dust and mild corrosive vapor performance vs -100/-150

High-capacity bidirectional TVS transient, ESD and wiring fault surge suppression per channel

Three-stage cascaded differential RC EMI filter network optimized for ultra-low mV TC signals

High-precision matched per-channel CJC temperature sensors for accurate thermocouple cold junction correction

Precision balanced lead compensation networks for 3-wire RTD loop resistance matching

Extra-thick reinforced physical channel isolation barriers to eliminate inter-channel low-level signal crosstalk

Matched IOP Hardware: Honeywell 16-channel TC/RTD low level analog input UCN IOP card

Incompatible Hardware: HART AI/AO, non-HART AI/AO, discrete DI/DO, pulse counter, serial communication FTAs

3. Technical Specifications

Channel Count: 16 independent low-level temperature input channels

Supported Field Sensors

Thermocouple: J, K, T, E, R, S, B, N (mV low-level signals)

RTD: Pt100, Pt1000 (2-wire, 3-wire configurations)

FTA Structure: Fully passive termination block; no isolated internal power; CJC sensing, lead compensation, filter and surge protection integrated per channel

PCB Protection: Medium-thick reinforced conformal coating; flammability UL94 V0

Terminal Type: Compression screw terminals, accepts solid/stranded copper wire up to 14 AWG; dedicated TC/RTD terminal pinouts

Form Factor: Standard Size B footprint, snap-on DIN rail mount for 35 mm standard rails

Operating Ambient: 0℃ ~ +60℃ indoor cabinet only; broader tolerance for high humidity, dust and mild corrosion compared to -100/-150 grades

Circuit Architecture

Three-stage differential low-pass EMI filtering to suppress heavy switching noise from large VFD banks, high-current contactors and medium-voltage switchgear without attenuating tiny TC millivolt signals

High-energy bidirectional transient overvoltage surge suppression on positive, negative and compensation lines

Tightly calibrated per-channel CJC sensors to eliminate cold junction offset drift across wide cabinet temperature swings

Precision 3-wire RTD lead balance resistors to cancel cable resistance measurement error

Extra-thick isolation partitions to fully block cross-channel mV signal bleed

Redundancy Compatibility: Fully supports primary/standby redundant TC/RTD LLAI IOP architecture; hot-swap IOP card replacement allowed

Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking heavy-duty flat ribbon cable connector directly mates to LLAI temperature IOP pin headers. Reinforced cable strain relief prevents pin header deformation or fracture under long-term tension of extension/compensation wiring harnesses. No onboard signal amplification; raw TC mV and RTD resistance signals pass through filtered, surge-protected networks directly to IOP. IOP performs A/D conversion, CJC offset calculation and linearization, transmitting temperature values and sensor fault diagnostics over UCN bus to Experion PKS controller.

Field Outer Terminals: Segmented labeled terminals: TC (+/-), RTD (Line1/Line2/Compensation) for 2/3-wire wiring schemes. No external loop power required for passive TC/RTD sensors; IOP supplies minimal sensing excitation for RTD loops.

Excitation Power Source: Low-level precision sensing excitation current sourced exclusively from paired TC/RTD LLAI IOP card.

5. Core Functions

Cable Strain Relief: Heavy-duty reinforced strain relief protects fragile LLAI IOP pin headers from mechanical stress, bending and fatigue fracture caused by continuous pulling force on multi-core TC compensation and RTD cabling.

Three-Stage Ultra-Low-Noise EMI Rejection: Three-layer differential filter architecture drastically attenuates strong plant electromagnetic interference, far outperforming single-stage (-100) and dual-stage (-150) variants; eliminates temperature PV drift, jitter and false sensor fault trips in high-noise motor and power equipment zones.

Reinforced Surge & Wiring Fault Protection: High-capacity TVS clamping diodes absorb intense induced voltage spikes, wiring short-circuit transients and switching arc surges, delivering robust protection for ultra-sensitive high-impedance low-level IOP input circuits.

Medium Heavy-Duty Anti-Corrosion Environmental Barrier: Medium-thick reinforced conformal coating fully encapsulates PCB substrate, solder pads, copper traces and all passive components. Ensures stable 24/7 precise temperature measurement under long-term high humidity, heavy dust buildup and trace mild acidic/alkaline corrosive fumes.

High-Accuracy Uniform Measurement Consistency: Per-channel matched CJC and RTD compensation networks guarantee identical cold junction correction accuracy and lead resistance cancellation across all 16 channels, eliminating channel-to-channel temperature offset mismatch.

Isolated Independent Single-Channel Maintenance: Separate terminal blocks support TC/RTD sensor replacement, loop resistance continuity testing, cold junction calibration check and fault troubleshooting for one temperature loop without disrupting the other 15 critical furnace, reactor, boiler or heat exchanger temperature measurements.

Redundancy Hot-Swap Capability: Standby redundant TC/RTD LLAI IOP cards can be replaced online without losing critical process temperature PV values, sensor open/short fault alarms or batch thermal profile data.

6. Application Scenarios

Applicable Industries

Petrochemical complexes, medium-heavy chemical processing plants, thermal & combined-cycle power stations, oil & gas refineries, pulp & paper mills, high-humidity water treatment facilities, medium-to-high humidity pharmaceutical batch production lines, furnace/kiln manufacturing.

Temperature Measurement Loops

K/J/T/E type thermocouples for furnace, reactor, boiler tube, stack gas, extrusion barrel temperature; Pt100/Pt1000 RTDs for bearing, cooling water, storage tank, process fluid, ambient cabinet temperature monitoring.

Cabinet Deployment

Dedicated compact slot for 16-point TC/RTD low-level analog input inside high-density space-saving critical DCS I/O control cabinets.

7. Wiring, Operation & Maintenance Guidelines

Wiring Standards

Thermocouple wiring must use matching grade TC compensation extension wire; strict polarity (+/-) reversal creates massive temperature offset errors.

3-wire RTD wiring: Run three identical-gauge matched-length copper leads to balance cable resistance; 2-wire RTD usable for short cable runs with minor resistance offset.

Deploy shielded twisted-pair low-noise instrument cable for all field runs; implement single-point shield grounding only at the DCS cabinet FTA side to eliminate ground loop noise and temperature drift.

Route TC/RTD low-level signal cables physically separated from high-current AC power cables to minimize EMI coupling interference; maintain maximum physical separation from VFD output wiring.

Spare Part Interchangeability

51304493-200 shares identical TC/RTD low-level measurement circuit topology with -100/-150 variants, fully electrically interchangeable for emergency field replacement. The -200 medium heavy reinforced grade is selected for cabinet environments with obvious high humidity, heavy dust or trace corrosive gas where -100/-150 lack long-term stability margin.

Standard Fault Troubleshooting Flow

Unstable temperature PV / full-scale high/low reading / sensor fault alarm → Retighten compression terminal screws → Test TC continuity / RTD loop resistance balance → Verify compensation wire polarity and integrity → Inspect wiring for opens/shorts → Confirm ribbon cable fully locked into TC/RTD LLAI IOP header → Diagnose operational health of paired temperature IOP card.