Honeywell 51309218-125 Low Level Analog Module

Configured for low-level RTD analog input multiplexing and field temperature signal termination in Honeywell TDC 3000 and Experion PKS systems, the Honeywell 51309218-125, also cataloged as the 51309218-125 Low Level Analog Input Multiplexer RTD FTA, provides direct physical/electrical execution.

Hardware Specifications

Cold Junction Compensation & Channel Isolation

The low-level multiplexer termination assembly interface conditions millivolt-level resistance changes across 16 dedicated RTD sensor input loops before passing digitized values to the primary I/O processor card. High-density channel isolation and filtering circuits attenuate common-mode electromagnetic noise and stray ground currents on field cabling, preventing signal drift. This low-level signal conditioning maintains measurement precision for temperature process loops running alongside standard 4-20 mA HART loop protocol analog channels within shared control cabinets.

Frequently Asked Questions

Q: Does the 51309218-125 FTA assembly support redundant I/O processor (IOP) topologies?

A: No, the 51309218-125 is engineered exclusively for a single IOP interface configuration; dual redundant IOP connections are not supported.

Q: What environmental coating and compliance specifications apply to this part number?

A: Part number 51309218-125 is non-CE compliant and is supplied without conformal coating.

Q: What type of field wiring termination hardware is integrated on the board?

A: Field conductor connections are established directly via onboard compression terminal blocks.

Field Installation Guidelines

1. Disconnect backplane power and field instrument loop power before installing or removing the FTA board from the mounting channel.
2. Fasten the assembly onto the standard enclosure rail using designated retention hardware to ensure mechanical stability.
3. Wire incoming 2-wire, 3-wire, or 4-wire RTD sensor leads to the corresponding compression terminals, ensuring screws are torqued to spec.
4. Route low-level RTD signal conductors in separate grounded metallic conduits away from high-voltage AC cables and switching inductive loads.
5. Ground all individual cable shield drain wires at the single-point cabinet enclosure earth bar to minimize noise interference on millivolt inputs.