Overview
The Allen-Bradley 1771-P4S is a single-slot AC power supply module designed for the 1771 Universal I/O chassis platform. The 1771-P4S Power Supply Module is a 5V, 8A power supply that can be used in the 1771-A1B, -A2B, -A3B, and -A4B Universal I/O Chassis. Supplying 5VDC at up to 8 Amps, it delivers stable backplane power for PLC-5 and 1771 I/O modules. This discontinued but widely available module provides regulated DC power directly to the I/O backplane, supporting both single and parallel configurations for increased capacity.
Key Features
- Input voltage range is 97 – 132 VAC rms at a frequency of 47 – 63 Hz
- Capable of delivering a regulated 5VDC output at up to 8 Amperes, the 1771-P4S supports substantial I/O loads
- Protected with a 1.5A 250V Slow-blow fuse located on the front panel
- Multiple power supplies can be connected in parallel using 1771-CT cabling, offering increased current capacity and improved operational reliability
- The front contains a P/S ACTIVE (power supply active) indicator that, when illuminated green, indicates the power supply and any supply connected through a power supply paralleling cable is operating normally
- Uses a 5-position terminal block (Allen-Bradley P/N 941274-05) for convenient wiring and supports 14 AWG single-wire copper conductors
Technical Specifications
- Input Voltage (Nominal): 120VAC, 47-63 Hz
- Input Voltage Range: 97 – 132 VAC rms
- Input Current: 0.9A at 120 VAC
- Output Voltage: 5VDC
- Maximum Output Current: 8 Amperes
- Real Input Power: 59 W at 50 to 60 Hertz line frequency
- Module Configuration: Single-slot I/O chassis mount
- Fuse Protection: 1.5A 250V Slow-blow fuse
- Operating Temperature: 0 to 60°C (32 to 140 °F)
- Storage Temperature: -40 to 85° C (-40 to 185 °F)
- Humidity: 5-95%, non-condensing
- Weight: 1.04 kilograms (2.3 pounds)
- Enclosure Type: Open enclosure
- Certifications: UL and CSA-certified
Typical Applications
The Allen-Bradley 1771-P4S is ideal for legacy PLC-5 systems and industrial I/O platforms that require stable 5VDC backplane power. Common installations include:
- Distributed I/O systems using 1771 series modules
- Machine control and automation equipment with moderate I/O density
- Factory floor and process control systems operating on standard 120VAC
- Maintenance and upgrade projects for existing PLC-5 installations
- Parallel power supply configurations for expanded current capacity
Compatibility & Replacements
Compatible With
- 1771-A1B, -A2B, -A3B, and -A4B Universal I/O Chassis
- Allen-Bradley PLC-5 controller systems
- 1771 series I/O modules (input, output, analog, communication)
- Industrial AC distribution systems (97–132VAC, 47–63 Hz)
Replaces / Drop-In Replacement For
- ALLEN BRADLEY 1771-P4S/A and ALLEN BRADLEY 1771-P4S/B series variants
- Allen-Bradley part number 96219271 (equivalent replacement)
Works With
- 1771-CT paralleling cable for connecting multiple power supply modules in parallel
- Compatible modules like -LSP, -LWP, -XP, -ZP, or another P4S for parallel operation
- PLC-5 programming software (RSLogix 5, Studio 5000)
- Remote I/O adapters and communication modules in 1771 chassis
