Product Overview
The Allen-Bradley 1756-PAR2 is a comprehensive redundant power supply kit engineered for the ControlLogix platform. This assembly bundles two 1756-PA75R power supplies, two 1756-CPR2 interconnect cables, and one 1756-PSCA2 chassis adapter module. Designed to deliver failsafe power redundancy, the 1756-PAR2 minimizes downtime risks in critical industrial applications.
Each 1756-PA75R accepts a wide input range of 85-264VAC (nominal 120/240VAC) and provides up to 75W of clean output power. The kit's modular design simplifies installation and ensures reliable operation across demanding environments.
Technical Specifications
| Parameter |
Value |
| Manufacturer |
Rockwell Automation |
| Module Type |
Redundant Power Supply bundle |
| Series |
ControlLogix |
| Part Number |
1756-PAR2 |
| Input Voltage (per 1756-PA75R) |
85-264VAC, 47-63Hz |
| Nominal Input Voltage |
120/240VAC |
| Output Power |
75W @ 0…60°C (32…140°F) |
| Current Capacity |
1.5A @ 1.2VDC; 4A @ 3.3VDC; 13A @ 5.1VDC; 2.8A @ 24VDC |
| Isolation Voltage |
250V continuous (reinforced insulation); tested at 3250V DC for 60s |
| Max Inrush Current |
20 Amperes |
| Hold-up Time |
2 cycles @ 60Hz; 2 cycles @ 50Hz |
| Annunciator Power |
240V AC 50/60Hz, 240V DC, 50mA, resistive only |
| Chassis Compatibility |
1756-A4, 1756-A7, 1756-A10, 1756-A13, 1756-A17 |
Key Features & Benefits
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Redundant Architecture: Two 1756-PA75R supplies work in parallel, providing automatic failover if one unit fails.
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Seamless Integration: The 1756-PSCA2 chassis adapter consolidates power from both supplies to the backplane, simplifying wiring.
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Space-Saving Design: The kit includes all necessary cables (1756-CPR2) and adapters, reducing component sourcing effort.
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Wide Input Range: Accepts 85-264VAC, making it suitable for global installations.
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Robust Protection: Reinforced isolation and high inrush handling ensure stable operation in harsh industrial settings.
Real-World Applications
The 1756-PAR2 is ideal for manufacturing plants, process control systems, and critical infrastructure where uninterrupted operation is non-negotiable. For example, in a continuous production line, a momentary power loss can halt production and incur significant costs. The 1756-PAR2 provides redundant power, ensuring that the control system remains operational even if one supply fails, thereby preventing costly downtime.
In oil and gas or power generation facilities, the rugged design and wide temperature range make it a dependable choice for remote or harsh environments.
Installation & Setup Guidance
To install the 1756-PAR2, first mount the two 1756-PA75R power supplies side-by-side at the left end of the chassis. Connect each supply to the backplane using the provided 1756-CPR2 cables. Then insert the 1756-PSCA2 chassis adapter, which will route power from both supplies to the backplane connector. Ensure the input power is within the specified range (85-264VAC) and that all connections are secure. No additional configuration is required for basic operation.
Maintenance & Reliability
Routine inspection should focus on the power supply fans (if any) and ensuring the input connectors remain clean and tight. Check the annunciator output periodically to verify system health. The redundant design means you can replace a failed supply without shutting down the system, provided you follow proper hot-swap procedures. Operating within the specified temperature range (0-60°C) will extend the lifespan of the units.
Compatibility & Integration
The 1756-PAR2 is designed specifically for ControlLogix chassis that support 1756-A4, A7, A10, A13, and A17. It integrates seamlessly with any ControlLogix controller and I/O modules. The kit works with standard 120/240VAC mains power, making it a universal solution for redundant power needs across the ControlLogix family.
Selection Guide & Purchasing Advice
Before purchasing, verify your chassis model and power requirements. The 1756-PAR2 is a complete kit, so no additional parts are required for basic redundant operation. For enhanced monitoring, consider adding an annunciator module (not included). PLC Source PRO offers genuine Allen-Bradley 1756-PAR2 kits with fast shipping and expert support.