Allen-Bradley 1746-P1 SLC Rack Mounting Power Supply

The Allen-Bradley 1746-P1 serves as the primary power source for SLC 500 modular hardware. This rack-mounted unit supplies essential DC voltage directly to the chassis backplane. It supports the processor and all installed I/O modules within the system. Because this module manages the entire power load, it requires installation in the leftmost chassis slot. The hardware effectively converts plant-side AC voltage into stable, regulated electronic power. This ensures consistent performance for sensitive automation components across the assembly.

Technical Performance and Specifications

• Input Voltage Range: 85–132V AC or 170–265V AC
• Input Frequency: 47 to 63 Hz
• Backplane Output (5V DC): 2.0 Amps
• Backplane Output (24V DC): 0.46 Amps
• User Power Output: 24V DC at 0.2 Amps
• Typical Power Consumption: 70 VA
• Operating Temperature: 0 to 60°C (32 to 140°F)
• Status Indication: Integrated LED for “Power OK” monitoring

Configuration and Safety Features

The 1746-P1 features a dual-voltage design for global industrial compatibility. Users must manually position the internal jumper to match their specific local line voltage. This manual selection prevents hardware damage during initial system commissioning. Furthermore, the supply includes a built-in hold-up time feature. This allows the PLC to maintain operation during brief voltage dips or momentary outages. Integrated fuse protection also shields the backplane from external electrical surges or short circuits. These protective measures minimize the risk of costly processor downtime.

Implementation and Mounting

This power supply fits perfectly into any SLC 500 chassis including 4, 7, 10, or 13-slot versions. The rugged terminal block facilitates secure wiring for incoming AC lines and ground connections. Additionally, the extra 24V DC user output provides convenient power for external sensors or switches. Engineers often choose this module for its proven reliability in harsh manufacturing environments. It maintains high efficiency even when operating at its maximum rated temperature. Consequently, the 1746-P1 remains a cornerstone for maintaining legacy SLC control systems.