Product Overview
The Allen-Bradley 1768-PA3 is a CompactLogix power supply module designed to deliver reliable backplane power for 1768 controllers. This industrial automation module accepts dual input voltages—85–265V AC or 108–132V DC—making it versatile across global installations. Engineered by Rockwell Automation, the 1768-PA3 ensures your CompactLogix system operates with stable, conditioned power for critical control tasks.
Key Features
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Dual Input Voltage: 85–265V AC or 108–132V DC for flexible power sourcing.
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Backplane Current: 1.4 A at 24V DC to energize connected modules.
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Integrated Protection: Internal non-replaceable fuse soldered in place; user-supplied overcurrent protection up to 15 A.
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High Efficiency: 75% typical efficiency reduces energy waste.
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Compact Design: Open-style enclosure, DIN-rail or panel mountable.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Brand |
Allen-Bradley |
| Part Number |
1768-PA3 |
| Product Line |
CompactLogix |
| Module Type |
AC Power Supply Module |
| Input Power |
85…265V AC; 108…132V DC |
| Input Frequency Range |
47…63 Hz (85…265V AC) |
| Input Power, Max |
120 VA/120 W |
| Efficiency |
75% Typical |
| Backplane Current |
1.4 Amps at 24 Volts |
| Power Dissipation, Max |
30 W |
| Power Consumption |
33.6 Watts |
| Internal Overcurrent Protection |
Non-replaceable fuse soldered in place |
| Recommended External Overcurrent Protection |
4…6 A @ 28.5…36.7 A²s |
| Isolation Voltage |
30 Volts Continuous |
| Inrush Current, Nom |
25 A @ 85…132V AC; 50 A @ 195…265V AC; 25 A @ 108…132V DC |
| Inrush Current, Max |
50 A @ 85…132V AC; 80 A @ 195…265V AC |
| Enclosure |
None (open-style) |
| Shipping Weight |
2 lbs. |
| Shipping Dimensions |
8 × 8 × 5 in. |
Installation & Setup Guidance
Before powering up your system, install a 1768 CompactLogix controller in the same bank as the 1768-PA3. Never use a 1769 power supply on a 1768 backplane—this can cause severe damage. The module supports DIN-rail or panel mounting; ensure adequate ventilation for the open-style enclosure. Use copper wire rated for 167°F (75°C), sized 14–22 AWG stranded or solid, with maximum insulation strip length of 1.2 mm. Apply the recommended external overcurrent protection (4–6 A) to safeguard the circuit.
Compatibility & Integration
The 1768-PA3 is compatible with 1768 CompactLogix controllers, including models 1768-L43, 1768-L43S, 1768-L45, and 1768-L45S. When used with 1769 Compact I/O modules, it can support up to eight modules in the same bank. Always respect power supply distance ratings to ensure each module receives adequate backplane power. This power supply does not provide output power to field devices—it only energizes the backplane circuitry.
Maintenance & Reliability
The 1768-PA3 features an internal non-replaceable fuse for overcurrent protection. The single LED indicator provides real-time status: green indicates normal operation, off means no input power or a fault, and red signals backplane output issues. Regularly inspect input connections and verify the fuse integrity. Keep the enclosure free of dust and debris to maintain cooling. With proper care, this power supply delivers long, dependable service in demanding industrial environments.
Selection Guide & Purchasing Advice
When ordering the 1768-PA3, confirm your input voltage range and available overcurrent protection. Verify compatibility with your 1768 controller model. For genuine Allen-Bradley parts and expert support, choose PLC Source PRO—your trusted source for industrial automation spares. Ensure you have the correct mounting hardware and wiring per the installation guidelines.