Product Overview

The Allen-Bradley 1771-P5 is a high-reliability DC-to-DC power supply module engineered for the Universal 1771 I/O chassis system. It is specifically designed to convert a 24V DC source into the stable 5.06V DC logic power required by PLC-5® processors and their associated I/O modules. Capable of delivering up to 8 Amperes of output current, the 1771-P5 is an essential component for distributed control systems and remote I/O racks where high-voltage AC power is unavailable.

This module supports redundant power configurations, allowing two 1771-P5 units to be linked in parallel using a 1771-CT cable. This setup ensures continuous system operation even if one power supply fails, significantly increasing the Mean Time Between Failures (MTBF) for critical industrial processes. The unit is designed for direct slot mounting, occupying two positions in a standard 1771 chassis, and utilizes a robust mechanical keying system to ensure correct backplane alignment.

Electrical Integrity and System Protection

The 1771-P5 is built to endure the electrical volatility of industrial environments. It features superior circuit isolation, rated at 1500V AC (RMS) or 2160V DC, effectively shielding the sensitive backplane logic from input power surges and grounding issues.

• Input Flexibility: Operates across a wide DC window of 20.5V to 30V DC, maintaining a steady 5.06V DC output without fluctuation.

• Switchable Power Delay: Features an adjustable power-loss delay timer, allowing users to select between 13.6ms and 60ms. This provides a buffer for the processor to save critical data during a momentary power interruption.

• Integrated Safety: Comes equipped with a 5A, 32V normal-blow fuse to prevent overcurrent damage to the internal circuitry.

• Thermal Efficiency: Designed to operate at full capacity within a 0 to 60°C temperature range without the need for power derating, making it suitable for unconditioned control cabinets.

Technical Specifications

• Manufacturer: Allen-Bradley (Rockwell Automation)

• Model Number: 1771-P5

• Module Type: DC Power Supply

• Input Voltage: 24V DC Nominal (20.5–30V DC Range)

• Output Voltage: 5.06V DC ± 0.06V

• Output Current: 8A (Maximum)

• Isolation Voltage: 1500V AC (RMS)

• Fuse Protection: 5A, 32V Normal Blow

• Operating Temperature: 0°C to 60°C (32°F to 140°F)

• Humidity Range: 5% to 95% (Non-condensing)

• Certifications: UL listed, CSA certified

• Weight: 1.18 kg (Approx. 2.6 lbs)

• Dimensions: 14.5 x 3.5 x 13.0 cm

Advanced Reliability Features

• Parallel Capability: Supports load sharing and redundancy when paired with a second module, ideal for high-availability manufacturing lines.

• Backplane Keying: Uses a specific keying band (between pins 2–4 and 6–8) to prevent accidental insertion of the wrong module type into the power slot.

• Rugged Construction: Built to withstand the vibration and shock levels typical of heavy industrial machinery and power generation facilities.

• Fast Status Diagnostics: Integrated visual indicators allow maintenance personnel to quickly verify input and output power status.