ABB Bailey APBU-44C (64669982) – Redundant Bus/Power Unit for INFI 90/NET 90 Racks

The ABB Bailey APBU-44C, part number 64669982, is commonly used in NET 90 / INFI 90 systems as a backplane bus/power unit to stabilize rack power distribution and maintain reliable system-bus connectivity. From my experience, plants keep one or two on the shelf because it tends to be the first line of defense for noisy power or intermittent rack communication. You might notice that replacing an aging APBU often clears sporadic I/O bus faults without touching the controllers or I/O cards.

Company’s Order Placement Process and Guarantees

• Warranty: 365 days coverage on this unit.
• Delivery: Typically ships in 1 week if in stock; no more than 1 month at the latest.
• Payment: 50% advance payment; full payment prior to delivery.
• Express options: FedEx, UPS, DHL.

Key Features

• Redundant bus support: Helps stabilize the system communication backplane in INFI 90/NET 90 racks, reducing nuisance trips.
• Backplane power conditioning: Typically smooths and distributes logic power from the rack supply, improving noise immunity in older cabinets.
• Status/diagnostics LEDs: Quick visual indication for power/bus health, useful for shift checks and first-fault isolation.
• Field-replaceable design: Plug-in card form factor; swap during scheduled windows with minimal wiring disturbance.
• Compatible form factor: Fits standard Bailey rack slots, so no mechanical modifications are usually required.
• Lifecycle-friendly: Works as a drop-in replacement for legacy racks, helping extend system life without a full migration.

Technical Specifications

Application Fields

Plants running legacy ABB Bailey NET 90 / INFI 90 systems—power generation, refining and petrochemicals, pipeline compressor stations, pulp & paper, metals, and water treatment—typically use the APBU-44C to stabilize rack power/bus performance. A maintenance lead in a CHP facility told us a simple APBU swap eliminated sporadic bus faults that only appeared during heavy load changes.

Advantages & Value

• Reliability gain: Smoother bus and logic power often translates into fewer unexplained card resets.
• Compatibility: Drop-in for standard Bailey racks—no software re-engineering, no re-landing of field wiring.
• Cost control: Extends system life while you plan phased migrations rather than a disruptive rip-and-replace.
• Serviceability: Easy to stock as a critical spare; field swap in a short maintenance window.
• Technical backing: We typically provide build/revision checks and installation notes so your team knows what to expect.

Installation & Maintenance

• Cabinet requirements: Install in a clean, ventilated control cabinet. Maintain airflow; avoid blocked louvers and cable congestion behind the rack.
• Wiring and grounding: Ensure rack earth and shield bonding are intact. Many intermittent bus issues trace back to poor grounding or shared noisy returns.
• ESD precautions: Use a grounded wrist strap. Handle the card by its edges and avoid touching components or edge contacts.
• Replacement practice: De-energize the rack if your site procedures require it; some sites allow controlled online replacement, but verify your DCS policy first.
• Routine checks: Inspect connectors for oxidation, confirm LED status during walkdowns, and log any unusual warming or odor.
• Firmware/labeling: Record hardware/revision stickers before and after swap so your asset list remains accurate; update cabinet card maps.
• Cleaning: If needed, use dry, oil-free compressed air; no solvents. Avoid forcing dust deeper into the rack.

Quality & Certifications

• Certifications: Units from the later ABB Bailey production era are typically CE-marked; many are UL Recognized for industrial control use. RoHS conformity may vary by production year for legacy hardware.
• Warranty: 365-day warranty from our side. Functional testing and visual inspection are performed prior to shipment in most cases.

If you’re matching a specific revision of APBU-44C (64669982), share the rack model and any existing card photos or labels. That seems to be the fastest way to verify interchangeability and ship the correct hardware the first time.