Product Summary
The 1768-PA3 delivers reliable backplane power exclusively for Rockwell Automation’s 1768 CompactLogix platform. Engineers select this module for its flexible dual-input voltage range and integrated overcurrent protection. This unit energizes connected modules but does not supply output power.
Product Procurement & Buyer Guide for the 1768-PA3-allen-bradley-compactlogix-power-supply/" title="1768-PA3 Allen-Bradley CompactLogix Power Supply" rel="noopener">1768-PA3
Understanding the Power Requirements
Procurement managers must confirm the voltage source matches the 1768-PA3 input range. This module accepts 85…265V AC or 108…132V DC. It operates within a frequency range of 47…63 Hz for AC input. Verify your facility’s power characteristics before ordering.
System Compatibility and Controller Selection
The 1768-PA3 works exclusively with 1768 CompactLogix controllers. Compatible models include the 1768-L43, 1768-L43S, 1768-L45, and 1768-L45S. You must install a controller in the same bank as the power supply. Never use a 1769 power supply on this backplane.
Sizing and Backplane Current Limits
This unit provides 1.4 Amps at 24 Volts to the backplane. Calculate your total module current draw carefully. The power supply can accommodate up to eight 1769 Compact I/O modules in one bank. Always check the distance rating for each module.
Efficiency and Power Budgeting
The 1768-PA3 achieves a typical efficiency of 75%. Its maximum input power is 120 VA or 120 W. The module dissipates a maximum of 30 Watts of power. Plan your control cabinet cooling around this dissipation value.
Overcurrent Protection Specifications
The module features an internal non-replaceable soldered fuse for protection. You must supply an external overcurrent device rated at 15 Amps maximum. The recommended external protection range is 4…6 A. This ensures safe system startup and operation.
Mounting and Enclosure Considerations
This power supply has an open-style enclosure. You can mount it on a DIN rail or directly on a panel. Check the wiring category of 1 for power ports. Use copper wire sized 14 to 22 AWG for connections.
Expert Technical Evaluation & Performance Review
Voltage Range and Isolation Performance
The 1768-PA3 provides an isolation voltage of 30 Volts continuous. This rating protects sensitive electronics from ground loops. The wide AC input range supports global voltage standards. Engineers value this flexibility for multi-site deployments.
Inrush Current Characteristics
This module exhibits a nominal inrush current of 25 A at 85…132V AC. At higher voltages of 195…265V AC, the nominal inrush current reaches 50 A. For DC input, the nominal value is also 25 A. The maximum inrush current hits 50 A and 80 A respectively.
Power Consumption and Thermal Management
The 1768-PA3 draws a maximum power consumption of 33.6 Watts. Its typical power dissipation is 7.5 Watts under normal load. Ensure adequate airflow around the open-style enclosure. This prevents thermal buildup during extended operation.
LED Status Monitoring
A single green LED indicates proper power application. This simple visual feedback allows for quick status checks. Operators can confirm operational status from a distance. This reduces troubleshooting time during system startup.
Wiring and Termination Guidelines
Use wire rated at 167 degrees Fahrenheit with a minimum insulation of 1.2 millimeters. The wiring category for power ports is 1. Stranded or solid copper wire works correctly. Follow these guidelines for a reliable electrical connection.
Deep-Dive Technical FAQ
Can I use this power supply with 1769 Compact I/O modules?
Yes, the 1768-PA3 supports up to eight 1769 modules in the same bank. You must consider the distance rating between modules and the controller. This rating ensures adequate backplane power for all modules.
What happens if I install a 1769 power supply on the 1768 backplane?
Never install a 1769 power supply on this backplane. This mismatch creates serious operational issues. The backplane design is exclusive to 1768 series hardware. Use the correct 1768-PA3 for proper operation.
How does the internal overcurrent protection work?
The module has a soldered, non-replaceable fuse inside. This fuse provides internal overcurrent protection. You must still supply an external overcurrent device rated at 15A. The recommended range is 4…6 A for optimal safety.
What are the Series A and B differences?
The 1768-PA3 comes in both Series A and Series B versions. Both series share the same electrical specifications. The series revision indicates minor hardware updates. Check your system requirements for compatibility.
What wire gauge should I use for connections?
Use copper wire sizes from 14 to 22 AWG. The wire must be stranded or solid core. Ensure the insulation rating matches 167 degrees Fahrenheit. This ensures safe and reliable power connections.
Logistics & Standard Packaging Details
- One Allen-Bradley 1768-PA3 CompactLogix Power Supply module
- Unit ships in standard industrial protective packaging
- Shipping weight is approximately 2 lbs
- Package dimensions are 8 x 8 x 5 inches
- Express shipping options are available via FedEx, UPS, and DHL
