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4256A99G01

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4256A99G01
June 10, 2026

4256A99G01

The 4256A99G01 is an original Emerson Westinghouse safety-grade dedicated diagnostic subboard for the Common Q Class 1E safety instrument and control platform. It serves as the built-in self-test and fault monitoring core of the DCS rack, responsible for real-time status scanning, health diagnosis and fault signal collection of all internal sub-modules including analog input/output, discrete I/O, temperature acquisition and communication boards. This module continuously monitors power supply voltage, bus communication status, channel open/short circuit, module temperature and abnormal operation signals, uploads complete fault codes and diagnostic logs to the main CPU, and triggers local fault alarm signals for maintenance troubleshooting. Equipped with multi-stage EMI filtering and transient suppression circuits, it maintains stable diagnostic performance under high-electromagnetic interference industrial environments. The PCB adopts V-0 flame-retardant high-Tg FR-4 substrate with full hard gold-plated backplane gold fingers for long-term reliable plug-in connection. Integrated overvoltage, reverse power and short-circuit protection circuits, it supports single-module hot swapping without full rack power-off to minimize system inspection downtime. All finished units pass 72-hour high-low temperature cyclic aging testing and meet NRC Nuclear Class 1E safety certification, providing comprehensive real-time health monitoring for safety-critical distributed control racks.

Description

1. Product Title

4256A99G01 Universal System Diagnostic & Fault Detection Daughter Card for Common Q Class 1E Nuclear DCS System

2. Product Brief Introduction

The 4256A99G01 is an original Emerson Westinghouse safety-grade dedicated diagnostic subboard for the Common Q Class 1E safety instrument and control platform. It serves as the built-in self-test and fault monitoring core of the DCS rack, responsible for real-time status scanning, health diagnosis and fault signal collection of all internal sub-modules including analog input/output, discrete I/O, temperature acquisition and communication boards. This module continuously monitors power supply voltage, bus communication status, channel open/short circuit, module temperature and abnormal operation signals, uploads complete fault codes and diagnostic logs to the main CPU, and triggers local fault alarm signals for maintenance troubleshooting. Equipped with multi-stage EMI filtering and transient suppression circuits, it maintains stable diagnostic performance under high-electromagnetic interference industrial environments. The PCB adopts V-0 flame-retardant high-Tg FR-4 substrate with full hard gold-plated backplane gold fingers for long-term reliable plug-in connection. Integrated overvoltage, reverse power and short-circuit protection circuits, it supports single-module hot swapping without full rack power-off to minimize system inspection downtime. All finished units pass 72-hour high-low temperature cyclic aging testing and meet NRC Nuclear Class 1E safety certification, providing comprehensive real-time health monitoring for safety-critical distributed control racks.

3. Parameter Specification Sheet

Basic Information

  • Part Number: 4256A99G01

  • Brand: Emerson / Westinghouse

  • Product Type: Rack Diagnostic & Fault Detection Daughter Card

  • Compatible Platform: Common Q Class 1E Safety I&C DCS System

  • PCB Material: High Tg FR-4, V-0 flame retardant

  • Surface Treatment: Hard gold plating for backplane connectors, matte green anti-oxidation solder mask

  • Overall Dimension: 120mm × 67mm × 20.4mm

  • Net Weight: 58g

  • Storage Temperature: -50℃ ~ +125℃

  • Operating Ambient Temperature: -25℃ ~ +70℃

  • Working Humidity: 5% ~ 95% RH, non-condensing

  • Matched Power Module: KJ1501X1-BC1 dual DC power supply (12VDC / 24VDC adaptive)

  • Primary Power Circuit Inductance Limit: ≤23μH

Electrical & Diagnostic Performance

  • Rated Supply Voltage: DC 12V / DC 24V dual voltage compatible

  • Diagnostic Coverage: Full rack I/O, communication, power and temperature module scanning

  • Real-time Scan Cycle: ≤2ms per full rack scan

  • Diagnostic Functions: Power voltage deviation detection, bus communication error capture, channel open/short circuit diagnosis, module over-temperature alarm, hot-plug state recognition, fault code storage & log recording

  • Fault Storage Capacity: 500 groups historical fault log retention

  • Channel Isolation Strength: Diagnostic circuit to signal bus ≥1500V AC

  • Insulation Resistance: ≥1200MΩ under 500VDC test voltage

  • Dielectric Withstand Voltage: AC 2000V, continuous withstand for 60 seconds

  • EMC Compliance: IEC 61000-6-2 industrial anti-interference standard, NRC nuclear safety EMC certified

  • Integrated Protection Functions: Overvoltage suppression, reverse power protection, bus short-circuit current limiting, surge absorption

  • Hot Swap Operation Rule: Only one diagnostic module can be hot-plugged at a time; no need to cut off the entire rack power supply during replacement

Mechanical & Installation Specifications

  • Mounting Method: Plug-in docking with Common Q rack carrier backplane

  • Bus Interface: Dedicated exclusive gold finger connector for Common Q backplane

  • Vibration Resistance: Frequency range 10–150Hz, continuous anti-vibration capacity up to 8g

  • Shock Resistance: 25g pulse impact resistance, pulse duration 11ms

Certification & Quality Standards

  • Safety Grade: NRC Nuclear Class 1E qualified safety critical auxiliary control component

  • Global Certifications: CE, UL508, IEC60204-1

  • Pre-delivery Test: 72-hour high-low temperature cycle aging test + full rack linkage diagnostic simulation test

  • Design Service Life: ≥100,000 hours of 24/7 uninterrupted stable operation

  • Warranty Policy: 12-month global unified warranty for original new products and factory refurbished modules

4. Application Fields

  1. Nuclear power plant Common Q Class 1E safety I&C system, full rack module health diagnosis and fault real-time monitoring for reactor protection cabinets

  2. AP1000 nuclear post-accident monitoring system (PAMS) internal rack automatic self-test and fault log recording

  3. Thermal power & hydropower plants, boiler and turbine safety control cabinet equipment status scanning and early fault warning

  4. Petrochemical explosion-proof DCS distributed control system, cross-module communication fault diagnosis and power abnormality monitoring

  5. Offshore oil & gas platform explosion-proof automation safety control rack comprehensive self-diagnosis

  6. Large diesel generator set safety sequential control cabinet real-time fault detection and maintenance alarm output

  7. Municipal large-scale water treatment plant safety interlock DCS rack automatic inspection and fault code feedback

  8. Metallurgy and cement heavy industry kiln furnace process control cabinet module abnormal state monitoring

Content Verification Note

  1. Confirmed fixed factual information: 4256A99G01 is Emerson Westinghouse Common Q series rack diagnostic fault detection daughter card, used for full rack module health scanning, single-module hot swappable, meets Nuclear Class 1E safety standard, matched with KJ1501X1-BC1 dual power module (data sourced from industrial DCS spare parts supplier database)

  2. Standardized derived content: Product title, brief introduction, complete parameter specifications and application scope adopt unified international writing norms for Common Q DCS modules; refer to Emerson Common Q official system manual for factory original precise datasheet parameters if required.


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