Rockwell / Allen-Bradley 1772-P1 System Power Supply

The Rockwell Allen-Bradley 1772-P1 is a system power supply engineered to convert facility AC power into regulated DC voltages for Allen-Bradley Bulletin 1772 PLC-2 processors and associated I/O chassis. This open-style unit mounts directly on the 1772 PLC-2 chassis and delivers the precise DC rails required for stable processor and I/O module operation in industrial control environments. The 1772-P1 does not provide battery backup; data retention during power interruptions is handled by the PLC's internal memory modules.

Technical Specifications

• Input Voltage: Selectable 110 V AC or 220 V AC; accepts 120 V AC or 220/240 V AC operation


• Output Voltage: 5.1 V DC (processor and I/O modules, 6.5 A maximum); 5 V DC (memory circuitry)


• Power Consumption: 75 VA


• Current Rating: 2 A maximum; 6.5 A on 5.1 V rail


• Fuse Protection: Slow-blow, 2 A, 250 V AC


• Operating Temperature: −10 °C to +100 °C


• Weight: 15.5 pounds (7.03 kg)


• Voltage Monitoring Range: 98–132 V AC (120 V setting); 196–250 V AC (220/240 V setting); minimum support 92 V (120 V) and 184 V (220/240 V)

Key Features

• AC-to-DC conversion with selectable input voltage


• Regulated dual-rail DC output for processor logic and memory circuits


• Built-in slow-blow fuse protection against overcurrent


• Undervoltage, overvoltage, and overcurrent protection


• Open-style chassis construction; requires user-provided environmental enclosure


• Not designed for water or liquid exposure

Typical Applications Power delivery for Allen-Bradley PLC-2 automation and control systems operating in industrial manufacturing, process control, and discrete automation environments.

Compatibility & Integration

• Processors: Bulletin 1772 PLC-2, 1772 Mini-PLC-2, 1772 Mini-PLC-2/15


• I/O Chassis: One 1772 I/O chassis (with adapter module) or integrated with processor modules on standard 1772 chassis