Honeywell MC-TAMR04 51305907-175 LLMUX2 RTD FTA

Honeywell MC-TAMR04 51305907-175 LLMUX2 RTD Field Termination Assembly

The Honeywell MC-TAMR04 (Part Number: 51305907-175) is a 16-channel Low-Level Analog Input Multiplexer 2 (LLMUX2) Field Termination Assembly (FTA) designed for resistance temperature detector (RTD) signal acquisition. Engineered for integration within Honeywell TotalPlant Solution (TPS), TDC 3000 High-Performance Process Manager (HPM), Advanced Process Manager (APM), and Experion PKS systems via standard Process Manager I/O (PMIO) links, this module replaces older electromechanical, mercury-wetted relay architectures with solid-state relay switching.

The MC- prefix and -175 suffix denote a factory conformal coated printed wiring board engineered to ISA S71.04 G3 harsh environment standards, fully CE compliant, and fitted with screw-clamp compression terminals. Each channel features dedicated analog conditioning designed to support standard 3-wire RTD sensor configurations, delivering common-mode rejection (CMRR) and series-mode filtering across marine engine rooms, offshore drilling assets, and hazardous processing plants.

Model Details

• Model Number: MC-TAMR04
• Part Number (MPN): 51305907-175
• Printed Wiring Assembly (PWA): 51305905-175
• Module Generation: LLMUX2 (Solid-State Architecture)
• Physical Assembly Size: Size B (Standard 12-inch / 307 mm rail footprint)
• Terminal Block Style: 3-tier compression screw terminals
• Environmental Finish: Conformal Coating (Tropicalization / Anti-Corrosion)

Technical Specifications

Key Features

1. Advanced Solid-State Relay Switching: Eliminates legacy mercury-wetted relay wear, delivering MTBF values and transient tolerance in high-vibration maritime and industrial settings.
2. 3-Wire RTD Lead Resistance Compensation: Automatically compensates for balanced loop resistances up to 15 Ω per lead across Pt100, Ni120, and Cu10 elements.
3. Dedicated Channel Diagnostics & Signal Isolation: High common-mode rejection ratio (CMRR 120 dB) with onboard fault-isolation between field loops, host processor, and power distribution rails.
4. Harsh Environment Resilience: Factory-applied conformal coating shields surface-mount components, copper traces, and header contacts against sulfurous environments, salt fog, high humidity, and airborne contaminants.
5. CE-Compliant Low-Noise Interface: Operates with shielded interconnect cables and CE-rated LLMUX power adapters to maintain EMC performance under heavy industrial electromagnetic interference.

System Compatibility

• I/O Processors (IOP): Fully supported by the 32-Channel LLMUX IOP module (Part Numbers: 51304362-100, 51304362-150, and MC-PAIL02). A single 32-channel IOP drives up to two 16-channel FTAs.
• Power Adapters: Requires CE-compliant LLMUX Power Adapters: MC-TALP02 (51309204-175) or MU-TALP02 (51309204-125).
• Host Controllers: Compatible with Honeywell High-Performance Process Manager (HPM), Advanced Process Manager (APM), Process Manager (PM), and Experion High-Performance Process Manager (EHPM / C200 / C300 migration links utilizing PMIO interfaces).
• Interconnect Cabling: Employs standard Honeywell 50-conductor shielded PMIO cable sets (51204128-xxx / 51204129-xxx).

Applications

• Marine Propulsion & Auxiliary Machinery: Continuous monitoring of main propulsion diesel exhaust temps, turbocharger inlet/outlet temperatures, camshaft bearing journals, and stern tube bearing RTD points.
• Oil & Gas Offshore Platforms: Gas compression manifold temperature monitoring, wellhead separator thermal balancing, and pump skid vibration-induced thermal monitoring under Class I, Div 2 / Zone 2 environments.
• Refining & Petrochemical Processing: High-density heat exchanger inlet/outlet thermal profiles, hydrotreater catalyst bed monitoring, and distillation column tray temperatures.
• Thermal Power Generation: Steam turbine casing expansion thermometry, generator stator winding embedded RTDs, boiler feed pump bearing monitoring, and condenser cooling water tracking.

Frequently Asked Questions

What does the “-175” suffix indicate on the Honeywell 51305907-175?

The “-175” designation indicates an assembly that is both CE compliant and conformal coated, equipped with compression terminal blocks. By contrast, a “-125” part is non-coated, and a “-275” model features screw-type barrier terminals rather than compression clamps.

Can the MC-TAMR04 accept thermocouple inputs?

No. The MC-TAMR04 is tailored exclusively for 3-wire RTD inputs (Pt100, Ni120, Cu10). For thermocouple inputs, the companion solid-state model MC-TAMT04 (51305890-175) must be used.

Does this FTA require an external power adapter?

Yes. CE-compliant LLMUX installations require power from a matching adapter assembly, such as the MC-TALP02 (51309204-175) or MU-TALP02 (51309204-125), to drive internal multiplexing circuits and deliver reference power to the IOP link.

What is the maximum field cable lead resistance allowed per channel?

The internal compensation loop handles up to 15 Ω of balanced lead resistance per wire. For lead resistance above this value, signal dropouts or span calibration errors will degrade acquisition accuracy.

Can I mix RTD types across different channels on the same MC-TAMR04 board?

Channel sensor types can be individually configured within the Honeywell system software (such as Pt100 European DIN alongside Ni120 channels), provided the field wiring and excitation limits stay within the engineering parameters defined for the board.