Yokogawa PW481 Modules

Technical Dossier

Product Details And Specifications

Yokogawa PW481 Series: Comprehensive Module Range and Technical Overview

The Yokogawa PW481 series comprises the primary power supply modules deployed within Yokogawa's CENTUM VP and CENTUM CS 3000 Distributed Control Systems (DCS). These modules are installed across critical process industries including petroleum refining, petrochemical complexes, nuclear power generation, LNG terminals, and large-scale chemical manufacturing facilities. The PW481 line provides regulated DC power to field control stations (FCS), I/O modules, and communication buses. Its redundant-capable architecture allows dual-module hot-standby configurations, a requirement in SIL-rated and continuous-process environments where unplanned downtime carries significant operational and safety consequences. Installed base spans facilities across Asia-Pacific, the Middle East, and Europe, with documented deployments exceeding 20 years of continuous service life in many sites.

The Evolution of PW481 Architecture

The PW481 series was introduced alongside the CENTUM CS 3000 platform in the late 1990s as a replacement for earlier power supply designs used in the CENTUM XL and CENTUM V generations. Early variants (PW481-10, PW481-50) established the baseline 24 VDC regulated output architecture with passive redundancy switching. Subsequent revisions introduced enhanced surge protection, wider input voltage tolerance (85–264 VAC universal input), and improved MTBF ratings exceeding 200,000 hours under standard operating conditions.

With the transition to CENTUM VP (introduced circa 2008), Yokogawa released updated PW482 variants offering improved efficiency ratings and compatibility with the VP's enhanced FCS backplane bus. The PW302 and PW312 sub-series addressed specific power budget requirements for smaller field control station configurations. As of 2026, the CENTUM CS 3000 platform has entered end-of-life support status, making PW481-series modules increasingly dependent on third-party MRO suppliers for spare parts continuity. Sites running CS 3000 must plan for long-term inventory stocking or controlled migration to CENTUM VP equivalents.

PW481 Full Catalog & Functionalities (SKU List)

The following SKUs represent the verified PW481 and related power supply module range for Yokogawa CENTUM CS 3000 and CENTUM VP systems. Each entry is classified by function and configuration.

Non-Redundant Power Supply Modules (Single Feed)

• PW481-10: 100–120 VAC input, 24 VDC/10 A output, single-slot, non-redundant FCS power supply
• PW481-50: 200–240 VAC input, 24 VDC/10 A output, single-slot, non-redundant FCS power supply
• PW481-11: 100–120 VAC input, 24 VDC/15 A output, enhanced current capacity variant
• PW481-51: 200–240 VAC input, 24 VDC/15 A output, enhanced current capacity variant
• PW481-S1: Universal AC input (85–264 VAC), 24 VDC output, wide-range single-feed module

Redundant Power Supply Modules (Dual Feed / Hot-Standby)

• PW482-10: 100–120 VAC input, redundant 24 VDC/10 A output, dual-module hot-standby configuration
• PW482-50: 200–240 VAC input, redundant 24 VDC/10 A output, dual-module hot-standby configuration
• PW482-11: 100–120 VAC input, redundant 24 VDC/15 A output, high-current redundant variant
• PW482-51: 200–240 VAC input, redundant 24 VDC/15 A output, high-current redundant variant
• PW482-S1: Universal AC input, redundant 24 VDC output, wide-range dual-feed module

Compact / Sub-Station Power Supply Modules

• PW302-10: 100–120 VAC input, 24 VDC output, compact FCS sub-station power module
• PW302-50: 200–240 VAC input, 24 VDC output, compact FCS sub-station power module
• PW312-10: 100–120 VAC input, 24 VDC/dual-output, enhanced sub-station power module
• PW312-50: 200–240 VAC input, 24 VDC/dual-output, enhanced sub-station power module
• PW302: Base variant, 24 VDC regulated output, standard sub-station configuration
• PW312: Dual-output sub-station module, supports mixed I/O bus power requirements

Sourcing Hard-to-Find & Obsolete PW481 Parts

The CENTUM CS 3000 platform reached end-of-active-production status, and Yokogawa's direct spare parts availability for PW481-series modules is progressively declining. DriveKNMS maintains a dedicated inventory program for lifecycle-extended support of the PW481 range. Stock is sourced through verified decommissioning projects, authorized surplus channels, and long-term storage programs with controlled environmental conditions (temperature, humidity, ESD protection).

All PW481 modules supplied by DriveKNMS are accompanied by full traceability documentation. For sites operating under IEC 61511 or ISA-84 functional safety frameworks, DriveKNMS can provide module-level test reports and configuration records to support management-of-change (MOC) documentation requirements. Customers requiring long-term blanket purchase agreements for annual maintenance shutdowns are accommodated with reserved stock allocations.

Quality Control for the PW481 Range

Power supply modules within the PW481 series require specialized validation procedures due to their role as the primary energy source for FCS backplane buses. DriveKNMS applies the following test protocol to all PW481 units prior to dispatch:

• Input voltage sweep test: 85–264 VAC across full load range to verify regulation stability
• Output load regulation test: 0–100% load step response, measured against Yokogawa factory tolerance bands
• Redundancy switchover test (PW482 variants): Simulated primary feed failure with switchover time measurement (<20 ms threshold)
• Ripple and noise measurement: Output DC ripple verified against 50 mV peak-to-peak specification
• Thermal burn-in: 48-hour continuous operation at rated load in controlled thermal environment
• Backplane connector inspection: Pin integrity, contact resistance, and keying alignment verified against CENTUM FCS slot specifications

Each unit is issued a test record retained for a minimum of 7 years, available upon request for audit and compliance purposes.