Honeywell 51304650-200 16‑Channel Galvanically Isolated Non-HART 4–20mA Analog Input FTA
June 10, 2026

Honeywell 51304650-200 16‑Channel Galvanically Isolated Non-HART 4–20mA Analog Input FTA

1. Product Overview 51304650-200 is medium heavy-duty reinforced galvanically isolated non-HART 4–20mA analog input Field Termination Assembly, exclusively matched with Honeywell isolated non-HART AI UCN IOP for Experion PKS DCS. It delivers independent full galvanic isolation per channel between DCS control side and field two-wire conventional 4–20mA transmitters with no HART signal overlay. -200 is medium heavy-duty reinforced industrial grade, superior to -100/-150 and below heavy-duty -325/-375. It adopts medium-thick reinforced conformal PCB coating, three-stage low-pass EMI filtering, high-energy TVS surge suppression, suitable for cabinets with long-term elevated humidity, heavy dust and mild-moderate corrosive chemical vapors. The whole 51304650 series shares identical core circuit topology with pin-to-pin electrical interchangeability for emergency field replacement of lower suffix models.

Description

2. Model Definition

51304650: Base model for 16-channel galvanically isolated non-HART analog input FTA

-200: Medium heavy-duty reinforced PCB protection grade

Medium-thick reinforced full-board conformal coating with enhanced resistance to high humidity, heavy dust and mild-moderate corrosive gas

High-capacity bidirectional TVS surge suppression for transients, ESD and line faults, higher impact energy tolerance than -100/-150

Three-stage cascaded RC differential EMI filter optimized for high-noise plant areas with dense MCC and large VFD clusters

Independent full per-channel galvanic isolation barriers to completely eliminate field-DCS ground loop circulating currents

Precision tight-tolerance isolated loop current limiting resistors for uniform short-circuit overload protection of transmitters and IOP inputs

Extra-thick reinforced physical channel isolation partitions to eliminate inter-channel analog signal leakage and measurement crosstalk

3. Technical Specifications

Channel Count: 16 fully independent channels with full galvanic isolation per channel

Compatible Field Devices

Two-wire non-HART 4–20mA transmitters: pressure, differential pressure, mass/vortex/turbine flow, radar/float level, RTD/TC temperature, pH, ORP, dissolved oxygen, conductivity analytical transmitters

FTA Structure: Passive isolated termination board without built-in power supply; integrated per-channel three-stage filtering, high-energy surge protection and short-circuit current limiting

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

Terminal Type: Compression screw terminals compatible with solid/stranded copper wire up to 14 AWG; independent isolated Ch+ / Loop– terminal pair for each channel

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

Operating Ambient: 0℃ ~ +60℃ indoor cabinet; superior humidity, dust and mild corrosion tolerance versus -100/-150; not designed for continuous salt fog environments (select -325/-375 for coastal/offshore salt fog scenarios)

Circuit Architecture Parameters

Three-stage low-pass differential filtering to suppress severe EMI interference from large VFD systems, motor control centers and medium-voltage switchgear

High-energy bidirectional TVS suppresses positive/negative transient high voltage on each isolated input loop

Galvanic isolation barrier eliminates measurement drift caused by ground potential offset between separate plant grounding grids

Calibrated tight-tolerance isolated current-limit resistors prevent transmitter burnout and IOP high-impedance input damage during field short faults

Extra-thick isolation partitions fully block inter-channel analog bleed and cross-input measurement interference

Redundancy Support: Fully compatible with primary/standby redundant isolated non-HART AI IOP; hot-swap FTA replacement without process shutdown is permitted

Approximate Unit Weight: 0.360 kg

4. Interface & Communication Configuration

Inner IOP Connection: Locking heavy-duty flat ribbon cable directly mates to isolated non-HART AI IOP pin headers. Reinforced cable strain relief prevents pin header deformation or fracture under sustained tension of long multi-core field instrument wiring harnesses.

Field Outer Terminals: Independent isolated Ch+ / Loop– terminals for each two-wire transmitter loop; field excitation circuit is fully galvanically separated from DCS control ground potential.

Signal Mechanism: Pure DC 4–20mA analog measurement signals; no HART coupling circuit integrated.

No auxiliary communication ports; only analog process signal transmission is supported.

5. Core Functions

Full per-channel galvanic isolation: Eradicates circulating ground loop currents at multi-ground plant sites, stabilizing PV readings and eliminating persistent measurement drift.

Three-stage heavy EMI noise rejection: Suppresses intense electromagnetic interference from VFD banks, MCCs and medium-voltage switchgear to remove measurement jitter and fluctuation.

High-energy surge & short-circuit fault protection: Withstands lightning-induced line transients, equipment startup surges and field short-circuit high voltage to protect costly sensitive IOP high-impedance input circuits.

Stable uniform loop overload protection: Precision matched current limiting safeguards all field transmitters equally against burnout from accidental wiring shorts.

Consistent input linear performance: Ultra-precision passive components deliver identical measurement response across all 16 channels to reduce bulk calibration workload.

Redundant hot-swappable maintenance: Seamlessly follows primary/standby IOP switching logic; single-channel disconnection and troubleshooting do not affect operation of the remaining 15 measurement loops.

6. Application Scenarios

Applicable Industries

Petrochemical complexes, medium-heavy chemical plants, combined heat & power stations, large oil & gas refineries, pulp & paper mills, high-humidity wastewater treatment, medium-to-high humidity pharmaceutical batch production lines

Typical Measurement Loops

Emergency safety pressure/differential pressure monitoring transmitters

High-flow process conventional flow transmitters

Large storage tank level monitoring transmitters

Furnace/reactor RTD/TC high-temperature transmitters

Corrosive media pH/DO/conductivity analytical transmitters

Suitable for multi-ground plant layouts, VFD-dense process areas, cabinets with long-term high humidity and heavy dust accumulation, and atmospheres containing mild-moderate acidic/alkaline volatile vapors. Not applicable for offshore platforms or coastal sites with continuous salt fog exposure; upgrade to -325/-375 ultra-heavy-duty grades for extreme salt fog environments.

7. Wiring Standards

Two-wire transmitter wiring: Transmitter positive → isolated FTA Ch+, transmitter negative → isolated Loop–; reversed polarity creates minor measurable PV offset.

Cable specification: Shielded twisted-pair instrument cable for all field wiring runs; cable shield grounded solely at DCS cabinet FTA side with field equipment end ungrounded to fully suppress ground loop noise.

Power cable segregation: Physically separate analog instrument cables from high-voltage AC power, MCC and VFD output wiring to minimize capacitive and inductive EMI coupling interference.

8. Incompatible Hardware

Isolated HART AI (51304644), isolated non-HART AO (51304640), isolated HART AO (51304648), all non-isolated AI/AO FTA modules, discrete DI/DO termination boards, TC/RTD dedicated FTAs, pulse counter termination blocks and serial communication terminal assemblies cannot be paired with this isolated non-HART AI IOP card.


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