Product Overview
The Allen-Bradley 1756-PA75 is a chassis-mounted AC power supply module designed specifically for the ControlLogix platform, providing regulated power to the backplane and all installed modules within a 1756 chassis. The Allen-Bradley 1756-PA75 accepts a wide input voltage range of 85 to 265 VAC at 47 to 63 Hz, making it suitable for global deployment without the need for input voltage selection or external transformers . The module delivers a maximum continuous output of 75 watts and supplies multiple regulated voltage rails to the backplane: 5.1V DC at 13A, 3.3V DC at 4A, 24V DC at 2.8A, and 1.2V DC at 1.5A . This multi-rail architecture directly supports the diverse voltage requirements of ControlLogix processors, communication modules, and I/O modules without requiring separate external power supplies for each rail.
The Allen-Bradley 1756-PA75 mounts in the leftmost slot of any 1756 ControlLogix chassis, including the 1756-A4, 1756-A7, 1756-A10, 1756-A13, and 1756-A17 models, and is available in Series A and Series B revisions . The module features front-panel status indicators for power and OK conditions, allowing operators to verify supply health at a glance. With reinforced insulation rated for 250V continuous and an inrush current limit of up to 30A, the Allen-Bradley 1756-PA75 is engineered for the electrical noise and transient conditions typical of industrial control cabinets . The power supply carries UL Listed, CSA, CE, FM, and C-Tick certifications, and is rated for Class I Division 2 hazardous locations with a T4 temperature code, ensuring suitability for use in demanding process environments where flammable vapors may be present under abnormal conditions .
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1756-PA75 |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Product Type | ControlLogix AC Power Supply Module |
| Series | A |
| Input Voltage Range | 85 to 265 VAC |
| Input Frequency | 47 to 63 Hz |
| Maximum Output Power | 75 W (0 to 60°C) |
| Output Rails | 5.1V @ 13A; 3.3V @ 4A; 24V @ 2.8A; 1.2V @ 1.5A |
| Inrush Current (Max) | 30 A |
| Isolation Voltage | 250V continuous, reinforced insulation |
| Mounting Position | Leftmost slot of 1756 chassis |
| Compatible Chassis | 1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17 |
| Operating Temperature | 0°C to 60°C |
| Certifications | UL Listed, CSA, CE, FM, C-Tick; Class I Div 2 T4 |
Main Features and Advantages
Wide-Range Universal AC Input: The Allen-Bradley 1756-PA75 accepts 85 to 265 VAC without any configuration or jumper changes, allowing the same power supply part number to be deployed across facilities with different mains voltages. This universal input capability simplifies spare parts inventory, reduces commissioning errors, and ensures that the 1756-PA75 can be installed in international projects without voltage-specific variants. The 47 to 63 Hz frequency range accommodates both 50 Hz and 60 Hz power systems, providing consistent performance regardless of regional grid standards .
Multi-Rail Output Architecture for Complete Chassis Power: Unlike single-output power supplies that require external regulators for downstream modules, the Allen-Bradley 1756-PA75 directly generates all four voltage rails required by the ControlLogix backplane from a single AC input. The 5.1V rail supplies the highest current demand at 13A for processor and I/O logic, while the 3.3V, 24V, and 1.2V rails serve communication interfaces, analog circuitry, and core processor functions respectively . This integrated approach eliminates wiring complexity and potential failure points associated with multiple external supplies.
Robust Industrial Construction and Hazardous Location Rating: The Allen-Bradley 1756-PA75 is rated for Class I Division 2 Groups A, B, C, and D hazardous locations with a T4 temperature code, meaning the power supply can be installed in environments where flammable gases or vapors are present under abnormal conditions . Reinforced insulation rated to 250V continuous protects the backplane from input transients and ensures safe isolation between the AC mains and the low-voltage control circuitry. The module’s 20A inrush limit prevents excessive current draw during power-up, reducing stress on upstream circuit breakers and preventing nuisance trips in cabinets with multiple ControlLogix chassis.
Direct Chassis Integration and Status Monitoring: The Allen-Bradley 1756-PA75 mounts directly into the leftmost slot of the 1756 chassis, eliminating external power wiring between the supply and the backplane. Front-panel LEDs indicate power and OK status, allowing maintenance personnel to verify supply operation without opening the cabinet or using a multimeter. When combined with the chassis’s backplane, the 1756-PA75 provides a clean, integrated power solution that reduces panel space requirements compared to external DIN-rail supplies and simplifies UL panel certification.
