Overview
The Allen-Bradley 1755-PB720 is a GuardPLC 2000 power supply module designed for industrial safety and automation applications. This power supply is rated for a voltage of 20.4 to 28.8 volts DC and converts the system supply voltage from 24 volts to 3.3 volts DC/5 volts DC, which is used for the internal I/O Bus. This unit was discontinued by the manufacturer on 2011-10-30, making it a legacy replacement part ideal for maintenance and repair of established GuardPLC 2000 systems.
Key Features
- Forms part of the GuardPLC 2000 modular system which broadly consists of a CPU module, a power supply module, and up to 6 local I/O modules
- Comes equipped with a back-up lithium battery, which has a life span of 4 years
- Front panel is equipped with 4 status indication LEDs that show the power supply voltage (24 volts), as well as output battery voltages for 3.3V DC and 5V DC
- Module can be back panel mounted on to the chassis and is located in the left-most slot of the GuardPLC 2000 chassis
- Tested, fully functional used equipment ready for integration
Technical Specifications
- Input Voltage Range: 20.4–28.8 VDC
- Output Voltages: 3.3V DC and 5V DC
- Module Type: Back-panel mounted chassis module
- Battery Backup: Lithium battery (4-year lifespan)
- Weight: 0.82 kilograms (1.8 lbs)
- Status Indicators: 4 LED indicators
- Condition: Used (tested and fully functional)
Typical Applications
- Legacy GuardPLC 2000 safety controller system repairs and maintenance
- Emergency replacement for failed power supplies in established automation systems
- Industrial machine safety circuit implementations
- Manufacturing and process control environments requiring certified safety functionality
Compatibility & Replacements
Compatible With
- GuardPLC 2000 CPU modules
- GuardPLC 2000 I/O modules (up to 6 local modules)
- GuardPLC 2000 chassis systems
- 24V DC industrial automation control systems
Replaces / Drop-In Replacement For
- Original Allen-Bradley 1755-PB720 units in GuardPLC 2000 systems
- Legacy GuardPLC 2000 power supply modules requiring replacement
Works With
- GuardPLC 2000 modular safety system platform
- Rockwell Automation safety controller ecosystems
- Industrial 24V DC supply networks
- Legacy Allen-Bradley automation and safety control systems
