1. Product Overview

2. Key Specifications

2.1 General

• Part Number: 405A720H05

• Manufacturer: Westinghouse / Emerson

• Product Type: Multibus Power Supply Module

• Compatible Systems: WDPF DCS, Ovation DCS (all chassis: 405A675G / 405A685G series)

• Revision: H05 (latest production revision)

• Status: Obsolete (EOL)；available as NOS (New Old Stock) or certified refurbished

• Warranty: 12 months (refurbished)；24 months (NOS)

2.2 Electrical

• Input Voltage: 100–240 VAC ±10%, 50/60 Hz (auto‑ranging, no switch required)

• Input Power: 350 VA max

• Output Voltages (Multibus standard):

  • +5 VDC: 25 A (125 W)

  • +12 VDC: 6 A (72 W)

  • −12 VDC: 3 A (36 W)

• Regulation: ±0.3% (full load, line variation)

• Ripple & Noise: < 30 mV p‑p

• Protection: OVP, OCP, SCP, OTP, inrush current limiting

• Efficiency: > 90% at full load (230 VAC input)

• Power Factor: > 0.95 (active PFC)

2.3 Physical

• Form Factor: Standard 6U DCS module

• Dimensions (W×H×D): 305 mm × 203 mm × 25 mm (12.0 in × 8.0 in × 1.0 in)

• Weight: ≈ 1.3 kg (2.9 lb)

• Mounting: 12‑slot Multibus chassis

• Connectors: Multibus edge connector (backplane), screw terminal block (AC input)

• Coating: Conformal coated (dust, moisture, corrosion resistance)

• Cooling: Forced air (chassis fan)

2.4 Environmental

• Operating Temperature: 0 °C to +60 °C (32 °F to 140 °F)

• Storage Temperature: −40 °C to +85 °C (−40 °F to 185 °F)

• Relative Humidity: 5% to 95% (non‑condensing)

• Shock/Vibration: IEC 60068‑2‑6 compliant

• MTBF: > 120,000 hours (25 °C, full load)

3. Main Features

1. Latest Revision Performance

   • H05 PCB with enhanced thermal design and high‑grade components; updated firmware for improved stability.

2. Higher Output Power & Efficiency

   • 25 A +5 VDC output (vs. 20 A on H03); >90% efficiency reduces heat and energy costs.

3. Advanced Protection Suite

   • OVP/OCP/SCP/OTP with auto‑recovery; inrush current limiting protects chassis backplane.

4. Hot‑Swap & Redundancy Optimized

   • Supports seamless online replacement in redundant Ovation/WDPF systems; no shutdown required.

5. Improved Diagnostics

   • Front‑panel LEDs with enhanced fault indication; supports remote alarm monitoring (system‑dependent).

6. Full Backward Compatibility

   • Direct replacement for 405A720H01/H02/H03; no chassis or software changes needed.

4. Applications

• Power Generation: Thermal, nuclear, combined‑cycle plants (WDPF/Ovation DCS).

• Process Industries: Petrochemical, pulp & paper, cement, water treatment, pharmaceutical.

• DCS Upgrades: Preferred replacement for aging H03 power supplies in legacy Multibus chassis.

• High‑Availability Systems: Redundant power configurations for 24/7 operation.

5. Comparison with 405A720H03

6. Installation Instructions

6.1 Pre‑Installation Safety

• ESD Protection: Always use an ESD wristband when handling the module.

• Power Off: Shut down the DCS chassis; disconnect AC input; wait 5 minutes for capacitors to discharge.

• Inspection: Check for bent pins, damaged connectors, or physical damage.

6.2 Installation Steps

1. Select Slot: Choose an available 6U Multibus slot in the 405A675G/685G chassis.

2. Insert Module: Align with chassis guides; insert firmly until fully seated in the backplane.

3. Secure Module: Tighten the front‑panel screw to ensure grounding and mechanical stability.

4. Connect AC Input: Wire 100–240 VAC to the terminal block (L = Line, N = Neutral, PE = Protective Earth).

5. Power On: Reconnect AC power; verify LED status: PWR (Green) ON, OUT (Yellow) ON.

6. Verify Output: Measure +5 VDC (±0.3%) and ±12 VDC at backplane test points.

7. LED Indicators

8. Maintenance & Troubleshooting

8.1 Preventive Maintenance (Quarterly)

• Visual Inspection: Check connectors for dirt, corrosion, or loose wiring.

• Cleaning: Use dry, low‑pressure compressed air (≤ 2 bar) to clean vents and components.

• Load Test: Verify output voltages under full load; compare to specifications.

• Cable Check: Inspect AC input cable for damage; replace if worn.

8.2 Troubleshooting

• PWR LED OFF: Check AC input, fuse, terminal block wiring, and chassis circuit breaker.

• OUT LED OFF:

  1. Disconnect all I/O modules; power on to test if fault persists.

  2. If fault clears, reconnect modules one by one to isolate the faulty load.

  3. If fault remains, replace 405A720H05.

• FLT LED ON:

  1. Check for short circuits in wiring or modules.

  2. Verify input voltage is within 100–240 VAC range.

  3. Replace module if fault persists.

• Blinking FLT LED: Ensure chassis fans are operational; clear blocked vents; reduce ambient temperature.

9. Storage & Handling

• Packaging: Store in original anti‑static packaging; keep in a cool, dry, dust‑free area.

• Temperature: −40 °C to +85 °C; avoid direct sunlight and heat sources.

• Handling: Hold the module by the edges only; avoid touching components or connectors.

• Transport: Use shock‑absorbent packaging; avoid heavy vibration during shipping.

10. Disclaimer