Description
System Role and Integration
The 3A99162G01 serves as the digital output interface within the Ovation Q-Line I/O architecture, functioning as the high-side switching element that translates controller logic commands into discrete field device actuation. As a QBO (Q-Line Binary Output) card, it mounts within the Q-Line I/O chassis and provides the critical interface between the Ovation controller’s low-voltage logic and field devices requiring higher voltage or current levels than standard logic outputs can provide.
This module occupies a specific niche in the Ovation I/O hierarchy, designed for applications where 24VDC logic levels are insufficient for field device operation. By supporting output voltages up to 60VDC and current capacity of 300mA, the card eliminates the need for external interposing relays in many applications, reducing panel complexity and potential failure points in power generation and heavy industrial environments.
Core Functionality and Signal Handling
The module provides discrete switching outputs capable of sourcing current to field devices such as solenoid valves, contactor coils, indicator lamps, and alarm annunciators operating at elevated voltages. Each output channel switches the positive side of the DC supply (high-side switching), with internal protection circuitry preventing damage from short-circuit conditions or inductive kickback from relay coils.
The 300mA current capacity supports direct driving of many small solenoids and relay coils without additional amplification, while the 60VDC voltage rating accommodates legacy field devices and specialized applications requiring higher operating potentials. The card interfaces with the Q-Line backplane to receive logic-level commands from the Ovation controller and reports channel status and diagnostic information back to the control system.
Platform Heritage and Operational Benefits
As a component of the Westinghouse Q-Line I/O family now maintained within Emerson’s Ovation portfolio, the 3A99162G01 reflects the ruggedized design philosophy developed for mission-critical power generation applications. The card serves as a direct functional replacement for the earlier 2840A79G01 module, providing spare parts continuity for legacy installations while incorporating improved component reliability and manufacturing consistency.
The QBO architecture separates the high-voltage switching circuitry from the sensitive controller electronics through robust isolation barriers, preventing ground loop issues and protecting the controller from field-side electrical transients. This isolation proves particularly valuable in switchyard environments and auxiliary equipment rooms where electromagnetic interference and ground potential differences are common.
Part 4: Technical Specifications
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Model Number: 3A99162G01
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Manufacturer: Westinghouse Electric Corporation (Ovation product line)
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Product Type: QBO Digital Output Card (Q-Line Binary Output)
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Q-Line Designation: 4QBO16 / QBO G01
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Output Voltage: 60VDC maximum
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Output Current: 300mA maximum per channel
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Switching Type: High-side sourcing output
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Isolation: Channel-to-logic and channel-to-ground isolation
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Substitutes For: 2840A79G01 (legacy part number)
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Mounting: Q-Line I/O chassis compatible
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Operating Temperature: 0°C to 60°C (32°F to 140°F)
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Storage Temperature: -40°C to 85°C (-40°F to 185°F)
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Humidity: 0% to 95% RH (non-condensing)
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Dimensions: Approximately 16 cm × 16 cm × 12 cm
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Weight: 0.11 kg to 0.8 kg (depending on packaging/configuration)
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Certifications: CE Mark compliant
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Protection: Short-circuit protection, inductive transient suppression
Part 5: Core Features & Customer Value
Elevated Voltage and Current Capacity: Unlike standard 24VDC logic output modules, the 3A99162G01 supports field devices operating at up to 60VDC with 300mA drive capability. For plant engineers, this eliminates the need for external interposing relays when driving legacy 48VDC or 60VDC solenoid valves and contactors, reducing panel wiring complexity, component count, and points of potential failure while improving system reliability.
Direct Legacy Replacement: The card functions as a direct substitute for the earlier 2840A79G01 module, providing critical spare parts availability for existing Q-Line installations. Maintenance managers can stock the 3A99162G01 as a drop-in replacement without modifying I/O configuration or field wiring, ensuring long-term supportability of mature Ovation control systems without costly wholesale migration to newer I/O platforms.
High-Side Switching Architecture: The module employs high-side switching topology, sourcing current to field devices rather than sinking to ground. This configuration provides better compatibility with various field device grounding schemes and simplifies troubleshooting by allowing technicians to verify output states with standard voltmeters referenced to ground. The architecture also provides inherent short-circuit protection, limiting fault current to prevent damage to wiring and power supplies.
Ruggedized Industrial Construction: Built to withstand the electrical noise and thermal stresses characteristic of power plant auxiliary systems, the PCB assembly utilizes industrial-grade components with extended temperature ratings. For facilities operating in harsh environments—such as coal-fired boiler houses or turbine lube oil skids—this robust construction minimizes intermittent failures caused by vibration, temperature cycling, or electromagnetic interference.
WESTINGHOUSE 3A99162G01
Part 6: Typical Applications
Fossil Fuel Power Plant Auxiliary Systems: The 3A99162G01 is extensively deployed in coal-fired and oil-fired generating stations for control of 48VDC and 60VDC auxiliary equipment. In boiler burner management systems, the module directly drives fuel valve solenoids and ignitor transformers operating at elevated voltages, while in turbine auxiliary skids it controls lube oil transfer pumps and hydrogen seal oil system valves that require higher current capacity than standard logic modules provide.
Switchyard and Electrical Auxiliary Control: Within power plant electrical auxiliary systems, this module controls breaker close/trip coils and switchgear operating mechanisms that frequently utilize 125VDC or 48VDC control voltages. The 60VDC rating accommodates the lower voltage ranges of these applications while providing sufficient current capacity to ensure reliable breaker operation during critical switching sequences.
Water Treatment and Demineralization: In demineralizer and reverse osmosis plants, the module controls chemical feed pump solenoids and valve actuators operating from 48VDC battery supplies common in these facilities. The high-side switching configuration proves advantageous in wet environments where ground reference integrity may vary, preventing erratic valve operation caused by ground potential fluctuations.
Legacy System Spare Parts Support: For Q-Line installations approaching end-of-life for original component availability, the 3A99162G01 provides critical sparing for the 2840A79G01 modules originally installed in 1980s and 1990s vintage Ovation systems. This sparing capability allows facilities to maintain regulatory compliance and operational readiness without immediate capital expenditure for complete I/O migration projects.
