ABB Bailey 086351-001 / 086351-003 INFI90 Termination / Interface PCB Assembly

Product Description

086351-003 is ABB Bailey INFI90 series printed wiring board assembly, a legacy termination interface board for INFI90 DCS I/O rack, compatible with analog or digital signal termination modules. It belongs to the same family as 086345-504 power supply board we previously covered. This board acts as signal breakout and conditioning interface between field wiring and INFI90 backplane I/O modules, providing terminal points for process sensor, valve, and interlock signals. It is a discontinued spare part for power, chemical and petrochemical DCS systems.

Key Functions

• Field signal termination and breakout board, routes 4-20mA analog, 24VDC digital input/output signals between field cables and INFI90 I/O backplane
• Built-in signal surge suppression and EMI filter components, protects I/O modules from transient voltage spikes from field wiring
• Signal isolation and common-mode noise reduction, reduces ground loop interference for analog measurement circuits
• Onboard terminal blocks for easy field wiring connection; supports quick disconnection for maintenance without removing the main I/O card
• Standard INFI90 card rack form factor, designed for rear rack mounting, works in conjunction with INFI90 AI/AO, DI/DO modules
• Passive + limited signal conditioning hardware, supports continuous 24/7 operation in heavy industrial control cabinets

Application Scenarios

• ABB Bailey INFI90 Distributed Control System (DCS) I/O rack signal termination interface
• Thermal power plants, chemical plants, oil & gas process control systems for pressure, flow, temperature and digital interlock signals
• Legacy INFI90 system spare part replacement and cabinet retrofit projects
• Field wiring junction for process transmitters, solenoid valves, limit switches and safety interlock devices

Common Issues & FAQ

• Unstable analog readings / noisy signals: Check for corrosion on terminal block screws; inspect aging surge protection components or degraded filter capacitors; verify field cable shielding and grounding.
• Open circuit / intermittent signal loss: Inspect PCB traces and solder joints for thermal fatigue cracks; check backplane connector pins for oxidation; verify tightness of all field wiring terminals.
• Field surge damage: Lightning or switching surges can burn out onboard protection components. Inspect for burnt traces or damaged TVS diodes; test channel continuity before re-commissioning.
• Refurbished / replacement unit note: After installation, perform continuity test on all signal channels, verify wiring polarity for 4-20mA loops, check isolation resistance, validate all input/output signals before returning DCS to online operation. Check PCB for aging capacitor degradation on refurbished boards.