Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1756-PA72 |
| Manufacturer | Allen-Bradley (Rockwell Automation) |
| Product Type | ControlLogix AC Power Supply |
| Input Voltage Range | 85–265 VAC |
| Input Frequency | 47–63 Hz |
| Input Power (Max) | 100 VA / 100 W |
| Output Power (Max) | 75 W @ 60°C |
| Output @ 1.2V DC | 1.5 A |
| Output @ 3.3V DC | 4 A |
| Output @ 5.1V DC | 10 A |
| Output @ 24V DC | 2.8 A |
| Inrush Current (Max) | 20 A |
| Isolation Voltage | 250 V continuous |
| Operating Temperature | 0°C to +60°C |
| Dimensions (H×W×D) | 140 × 112 × 145 mm |
| Weight | 1.12 kg |
| Wire Size | 14 AWG copper |
| Terminal Torque | 0.8 N·m (7 lb·in) |
Main Features and Advantages
The 1756-PA72 delivers a straightforward value proposition: reliable, certified power for ControlLogix chassis with the widest possible input voltage tolerance. Its 85–265 VAC auto-ranging input accepts both 120V and 240V nominal systems without jumper changes, making the same part number suitable for installations across North America, Europe, and other regions with different distribution voltages . This flexibility simplifies spare parts stocking for multi-site operations and reduces the risk of misconfiguration during replacement.
Backplane power distribution is carefully balanced to support typical ControlLogix module loads. The 1756-PA72 provides 10 A at 5.1V, the primary rail for most digital and communication modules, along with 4 A at 3.3V and 2.8 A at 24V for specialty and analog modules . The 1.2V rail supplies 1.5 A for termination and reference circuitry. These ratings accommodate a fully populated chassis with a mix of controller, communication, and I/O modules without exceeding the supply’s capacity under normal operating conditions.
Status indication and fault diagnosis are built into the 1756-PA72 design. A green status indicator illuminates during normal operation; if the indicator extinguishes, the user can follow a structured troubleshooting procedure that includes verifying line voltage, checking backplane load against the supply rating, and reseating the module . The power supply also provides a solid-state relay contact for system-level recognition of supply status, enabling the controller to detect power supply faults and trigger appropriate alarms or shutdown sequences.
Application Field
The 1756-PA72 is deployed in virtually every industry where ControlLogix systems are installed in standard industrial enclosures. In manufacturing plants, it powers chassis containing Logix controllers, EtherNet/IP communication modules, and digital and analog I/O for production line control, press automation, and material handling systems. The wide input voltage range is particularly valuable in facilities where line voltage may fluctuate or where equipment is relocated between buildings with different distribution configurations.
Water and wastewater treatment facilities rely on the 1756-PA72 to power ControlLogix systems controlling pump stations, aeration blowers, and chemical feed equipment. The 75 W output capacity is sufficient for chassis configurations typical of these applications, where a controller, a communication module, and a moderate complement of I/O modules are concentrated in a single rack. In oil and gas pipeline operations, the 1756-PA72 powers remote terminal unit (RTU) style ControlLogix installations in compressor stations and metering skids, where reliable operation across wide input voltage variations is essential for continuous pipeline monitoring and control.
