Honeywell 8C-PAIMA1 Series 8 Low-Level Analog Input Module

Honeywell 8C-PAIMA1 Series 8 Low-Level Analog Input Module

The Honeywell 8C-PAIMA1 (Part Number: 51454473-175) is a high-density, 16-channel Low-Level Analog Input (LLAI) module engineered for Honeywell Experion® Process Knowledge System (PKS) Series 8 I/O architectures. Designed to operate alongside the C300 controller platform, this module provides direct, high-resolution acquisition of low-level millivolt (mV), Thermocouple (TC), and Resistance Temperature Detector (RTD) signals without requiring interposing signal transmitters or signal-conditioning barriers.

The 8C-PAIMA1 features G3-grade conformal coating on its printed wiring assembly (designated by the “8C” prefix), making it suitable for deployment in corrosive industrial environments, chemical processing offshore plants, and marine machinery spaces exposed to salt fog, humidity, and atmospheric sulfur. The module mounts directly onto a dedicated Input/Output Termination Assembly (IOTA) and supports full Module Removal and Insertion Under Power (RIUP) to ensure zero-downtime maintenance on critical monitoring loops.

Model Details

• Manufacturer: Honeywell Process Solutions
• Model Code: 8C-PAIMA1
• Manufacturer Part Number (MPN): 51454473-175
• Product Type: Low-Level Analog Input (LLAI) Module – RTD / TC / mV
• I/O Family: Series 8 I/O Platform
• Conformal Coating: Yes (ISA G3 Harsh Environment Rated)

Technical Specifications

Terminal Allocations & Wiring Topology

• Terminal (+) / In+: Positive thermocouple leg or excitation high / signal high for RTD.
• Terminal (-) / In-: Negative thermocouple leg or signal return for RTD.
• Terminal (Comp / Return): Compensation return for 3-wire/4-wire RTD circuits.
• Terminal (Shield / Ground): Dedicated field instrument shield drain, connected to the internal chassis ground plane through low-impedance capacitive/direct grounding traces.

System Compatibility

• Host Control Platforms: Honeywell Experion® PKS (R300, R400, R430, R500, R510, R520 series)
• Controllers: C300 Controller, Series 8 Control Bridge
• Carrier / IOTA Assemblies:
  • 8C-TAIMA1 / 51307171-175: 16-channel Non-Redundant IOTA (Conformally Coated)
  • 8U-TAIMA1: Non-Coated 16-channel Non-Redundant IOTA
  • 8C-TAIM01: Legacy Series 8 Low-Level AI IOTA
• I/O Link Cables: Standard Honeywell Series 8 IOLINK drop cables (51202971-102 series)

Part Number Cross-References

• Honeywell Model Number: 8C-PAIMA1
• Honeywell PWA / Assembly Part Number: 51454473-175
• Non-Coated Alternate Model: 8U-PAIMA1 (Part Number: 51454473-275)
• Associated IOTA Part Numbers: 8C-TAIMA1 (51307171-175), 8C-TAIM01 (51306999-175)

Applications

• Marine Main Engine Exhaust Gas Monitoring: Direct thermocouple integration on slow-speed two-stroke and four-speed marine diesel engines for continuous cylinder exhaust temperature monitoring and turbocharger inlet/outlet gas metrics.
• Marine Propulsion Thrust & Journal Bearings: High-accuracy 3-wire and 4-wire Pt100 RTD inputs directly reading main propulsion shaft bearings, stern tube bearings, and reduction gearboxes.
• Refinery & Petrochemical Furnaces: Multi-point temperature surveillance across cracking columns, furnace tubes, catalytic reactors, and distillation towers.
• Offshore Oil & Gas Turbomachinery: Gas turbine exhaust gas temperature (EGT) arrays, compressor bearing stator winding monitoring, and separator vessel thermowells.
• Turbine Generator Winding Temperature Protection: Resistance monitoring across high-voltage turbine generator stators requiring high galvanic group isolation.

Frequently Asked Questions

Can the Honeywell 8C-PAIMA1 handle both Thermocouples and RTDs simultaneously?

Yes. The 16 channels on the 8C-PAIMA1 are individually software-configurable within Honeywell Experion Control Builder. You can assign a Type K thermocouple to Channel 1, a 3-wire Pt100 RTD to Channel 2, and a -50 to +50 mV sensor to Channel 3 without hardware jumpers.

What is the difference between 8C-PAIMA1 and 8U-PAIMA1?

The core functional circuitry and firmware are identical. The prefix “8C” denotes that the printed circuit board has ISA G3-grade conformal coating applied for corrosion, chemical, and moisture protection. The “8U” version is non-coated and intended solely for controlled, non-corrosive control rooms.

Does the 8C-PAIMA1 require external cold junction reference blocks for thermocouples?

No. The companion IOTA (such as the 8C-TAIMA1) features embedded high-accuracy isothermal cold junction reference thermistors right at the screw terminals, providing real-time hardware-compensated cold junction readings.

Can I replace an 8C-PAIMA1 module while the C300 controller is running?

Yes. The Series 8 architecture natively supports Removal and Insertion Under Power (RIUP). You can extract a faulty module and insert a replacement without turning off cabinet power or causing bus dropouts on neighboring modules.

How does the module indicate a broken or severed thermocouple lead?

The module features configurable open-circuit burn-out detection. In the module configuration block in Experion PKS, you can assign each channel to fail Upscale (reading maximum scale to trip safety alarms) or Downscale (reading minimum scale), alerting the control system instantly to sensor failure.