YOKOGAWA SPW481-53

Core Technical Specifications (SPW481-53 as primary standard)

• Input AC Voltage: 100–120 VAC single-phase, 50/60 Hz
• DC Output Multi-Rail Specifications: +5VDC / 12A, +24VDC / 6A, ±15VDC / 2A
• Redundancy Support: Dual-module parallel hot redundant operation, bumpless automatic load transfer upon single module failure
• Environmental Grade: ISA Standard G3 (resistant to H₂S, SO₂ industrial corrosive gas)
• Operating Temperature Range: -20°C ~ +70°C
• Shock & Vibration Resistance: IEC 60068-2-6 vibration test 10–150Hz, IEC 60068-2-27 shock test 15g peak
• Net Weight: 1.5 kg
• Enclosure Dimensions: Standard Yokogawa vertical rack module size 50mm (W) × 44mm (D) × 277mm (L)
• Protection Functions: Overvoltage, overcurrent, short-circuit, over-temperature, input under-voltage lockout protection
• Certifications: CE, UL, IEC 61508 SIL 2 functional safety certification

Material Composition & Structural Features

1. Outer Enclosure: High-strength flame-retardant orange ABS plastic housing with vertical ribbed heat dissipation structure; front panel integrated transparent observation window for LED status indicators
2. Internal PCB Substrate: High-Tg FR-4 flame retardant circuit board coated with transparent acrylic conformal coating to resist industrial corrosive gas, moisture and dust deposition
3. Power Conversion Components: Low-loss soft-switching MOSFET power tubes, high-temperature long-life electrolytic capacitors, multi-stage EMI filter inductors and X/Y safety capacitors
4. Connection Interface: Rear side gold-plated edge connector matching Yokogawa DCS backplane bus; front panel removable terminal blocks for auxiliary power wiring; 4 LED diagnostic indicators (Input Power Normal, Redundancy Active, Overheat Fault, Output Short Circuit)
5. Mounting Mechanism: Vertical rack slide-in structure with spring locking buckle for hot-swap replacement without full cabinet power shutdown

Working Principle

1. Grid AC power enters multi-stage EMI filter circuit to suppress power line surge, radio frequency interference and harmonic distortion generated by other industrial frequency conversion equipment
2. Full-bridge rectifier converts AC to bulk DC voltage, filtered by primary large-capacity energy storage capacitors
3. Soft-switching resonant converter circuit operates at high switching frequency to step down high-voltage DC into multiple isolated low-voltage DC power rails (+5V, +24V, ±15V) with independent voltage regulation loops for each output channel
4. Dual redundant parallel load-sharing control circuit enables two SPW481-53 modules to equally divide total system load; internal cross-monitoring communication bus continuously exchanges operating status data between redundant units
5. Multi-point temperature sensors, output current sampling resistors and input voltage detection circuits continuously monitor all operating parameters; any out-of-limit condition triggers rapid protective cutoff of corresponding output rail while maintaining power supply to critical safety control circuits
6. Front panel LED indicators latch fault status after protection activation, retaining fault display even if partial output power is still maintained

Application Scenarios

• Yokogawa CENTUM VP / CS3000 DCS field control stations for petrochemical refineries, ethylene plants
• Thermal power plant boiler, steam turbine, generator auxiliary control cabinets
• Natural gas pipeline compression station remote control rack power supply
• Fertilizer chemical plant, coal chemical process automation control systems
• Pharmaceutical continuous production batch control DCS racks

Installation Requirements

1. Rack Mounting: Slide vertically into dedicated power supply slots on Yokogawa DCS backplane; install redundant paired modules in adjacent slots to optimize load-sharing performance
2. Ventilation Clearance: Maintain minimum 30mm vertical air circulation gap above and below each module; do not block the ribbed heat dissipation surface on the module side housing
3. Wiring Torque Standard: Auxiliary wiring terminal block screws tightened to 0.9–1.1 N·m; AC input wire cross-section ≥ 1.25 mm²
4. Grounding Standard: Cabinet PE protective ground bus connected to module ground terminal with copper wire cross-section ≥ 2.5 mm²
5. Redundancy Configuration Rule: When deploying dual redundant power supply, both modules must use identical model SPW481-53; mixed standard SPW481 and SPW481-53 will cause unstable load-sharing and redundant transfer failure

Operation & Maintenance Precautions

1. Hot-Swap Operation Rule: Only perform module hot-swap replacement when the redundant paired unit is confirmed to operate normally via front panel “Redundancy Active” LED; never remove both redundant power modules simultaneously
2. Environmental Maintenance: Conduct quarterly inspection of conformal coating integrity on internal circuit boards; if coating peels or cracks due to corrosive gas exposure, replace the module immediately to prevent short-circuit faults
3. Capacitor Lifespan Monitoring: Electrolytic energy storage capacitors have rated service life of 100,000 hours at 40°C operating temperature; replace modules after 10 years of continuous industrial operation to avoid capacitance degradation and output ripple surge
4. Fault Reset Operation: After protective shutdown triggered by short-circuit or over-temperature, fully disconnect AC input power supply for minimum 3 minutes to clear fault latch status before restarting the module
5. Storage Restriction for Spare Modules: Store spare SPW481-53 modules in temperature-controlled warehouse (10°C ~ 30°C) with relative humidity ≤ 60%; avoid long-term storage in chemical plant on-site spare parts cabinets exposed to corrosive gas