Allen-Bradley 9902A1 Voltage Monitor Card 9902A1

Description:

The Card 9902A1 Voltage Monitor Card 9902 is used in industrial control systems to monitor incoming supply voltage and provide protective signaling for power supervision and equipment operation. Commonly installed in PLC systems, industrial control panels, power distribution equipment, and machine automation systems where continuous voltage monitoring is required to detect undervoltage, overvoltage, or power loss conditions. Maintenance teams, OEMs, and system integrators use this voltage monitor card for replacement of failed monitoring boards, preventive maintenance, restoration of power monitoring functions, and industrial control system repairs. Publicly available documentation for this legacy card is limited, so specifications below are based on typical industrial voltage monitor card applications rather than a manufacturer datasheet. 

Applications:

The Card 9902A1 Voltage Monitor Card 9902 is designed to supervise electrical supply voltage and provide status feedback to industrial automation systems. It is commonly used in manufacturing facilities, process control systems, motor control centers, utility equipment, and OEM machinery where reliable voltage monitoring helps protect electrical equipment and maintain system uptime. 

Technical Specifications:

• Manufacturer Part Number (MPN): 9902A1
• Model: 9902
• Product Type: Voltage Monitor Card
• Function: AC/DC supply voltage monitoring and protective status indication
• Monitoring Type: Overvoltage, undervoltage, and power loss detection (application dependent)
• Installation: Rack-mounted or control panel module (system dependent)
• Interface: Industrial control system backplane connection
• Application: Power monitoring and equipment protection
• Compatible Equipment: Legacy industrial control and automation systems using the 9902 platform
• Mounting: Plug-in circuit card
• Status: Legacy industrial replacement component

Common Replacements:

• 9902A2 Voltage Monitor Card
• 9902A3 Voltage Monitor Card
• 9902B1 Voltage Monitor Card