Allen-Bradley 1756-PB75R DC Redundant Power Supply

The Allen-Bradley 1756-PB75R serves as a high-availability power solution for ControlLogix hardware platforms. This redundant module ensures continuous system operation by allowing two power supplies to share the chassis load simultaneously. If one unit fails, the remaining supply instantly assumes the full load without disrupting the PLC processes. This architecture significantly increases the reliability of mission-critical industrial applications.

Core Technical Specifications

• Input Voltage Range: 18 to 32V DC
• Nominal Input Voltage: 24V DC
• Maximum Output Power: 75 Watts @ 60°C
• Hold-up Time: 20 milliseconds
• Peak Inrush Current: 30 Amperes
• Isolation Voltage: 250V DC (Continuous)
• Status Signaling: Integrated visual LED indicator
• Chassis Compatibility: 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17

Advanced Features and Safety

The module includes sophisticated protection circuitry to handle industrial power fluctuations effectively. It features a robust isolation rating tested at 3250V DC for 60 seconds to protect sensitive backplane components. Furthermore, the unit complies with ATEX and IECEx standards for use in specialized environments. An integrated annunciator contact allows for remote monitoring of the power state via a 90V DC signal.

Installation Requirements

Successful deployment requires specific proprietary accessories to enable redundancy features. Users must utilize the 1756-CPR2 cable to link the power supply to a 1756-PSCA2 chassis adapter. This connection facilitates the load-sharing logic between the twin power modules. Operators should avoid disconnecting cables while the system remains energized to prevent electrical arcing. Proper thermal management ensures the unit stays within the 0 to 60°C operational temperature window.