Overview
The Allen-Bradley 1771-P7 is an external AC power supply module designed for PLC-5 family systems and Mini-PLC-2 controllers. This 1771-P7 converts 120V or 220V AC line power to regulated 5VDC backplane output, supporting I/O chassis modules and processor cards in legacy Allen-Bradley automation installations.
Key Features
- 16A maximum output at 5VDC for backplane power distribution
- Wide input range: 97–264 VAC at 50/60 Hz (dual 120V/220V selectable)
- Stand-alone operation – cannot be paralleled with other supplies; prevents processor data loss
- Regulated output voltage: 5.06VDC ±3.8%, ensuring stable I/O module operation
- D-Shell connector interface for secure backplane attachment
- Powers one 1771-A1B, -A2B, -A3B, -A3B1, or -A4B I/O chassis
Technical Specifications
- Input Voltage (120V): 97–132 VAC at 2.0A, 50/60 Hz
- Input Voltage (220V): 195–264 VAC at 1.3A, 50/60 Hz
- Output Voltage: 5.06VDC ±3.8%
- Output Current: 16A maximum at 5VDC
- Input Power: 108W (Real) / 176VA (Apparent)
- External Transformer: 270VA at full load
- Isolation Voltage: Tested to 1200V AC for 1 second
- Operating Temperature: 0°C to 60°C (32°F to 140°F)
- Mounting: Panel or chassis-mounted; externally located
- Certifications: UL Listed Industrial, CE, CUL, C-TICK, MARINE
- Weight: 6.95 lbs
Typical Applications
The 1771-P7 is used in legacy PLC-5 automation systems where external power is required for I/O chassis operation. Common applications include:
- Discrete manufacturing and machine tool control
- Assembly line and material handling systems
- Industrial process control with distributed I/O racks
- Retrofit and rebuild projects for existing PLC-5 installations
- Panel-mounted or remote I/O chassis power distribution
Compatibility & Replacements
Compatible With
- PLC-5 family processors (all versions)
- Mini-PLC-2/02, Mini-PLC-2/05, Mini-PLC-2/16, Mini-PLC-2/17
- 1771-A1B, -A2B, -A3B, -A3B1, -A4B I/O chassis
- 1771 Adapter Module series
- Allen-Bradley automation systems requiring external backplane power
Replaces / Drop-In Replacement For
The 1771-P7 is the direct power supply for PLC-5 configurations. Not compatible with 1771-A1, -A2, or -A4 (older) I/O chassis models. For newer ControlLogix or CompactLogix systems, alternative power supplies are required.
Works With
- 1771-CP1 power cable (0.32m for panel-mounted chassis)
- 1771-CP2 power cable (1.52m for rack-mounted chassis)
- 1771-CP3 power cable (1.68m for remote chassis)
- Legacy Allen-Bradley automation systems and engineering tools


















