Product Overview

The 1746-P2 is a high-capacity chassis-mounted power supply designed exclusively for the Allen-Bradley SLC 500 modular hardware platform. It serves as the primary energy source for the system backplane, converting AC input into the regulated DC voltages required by the SLC processor and associated I/O modules. Occupying the dedicated power supply slot on the far left of any 1746 chassis, the 1746-P2 provides a robust power solution without consuming any of the system's available I/O slots.

This module is engineered for global compatibility, featuring a user-configurable jumper that allows it to operate on either 120V AC or 240V AC nominal voltages. With its integrated internal fuse and superior isolation ratings, the 1746-P2 ensures stable operation for complex PLC architectures, shielding sensitive logic components from common industrial power disturbances and transient spikes.

Technical Characteristics

• Input Voltage Support: Dual-range 85–132V AC or 170–265V AC (Selectable via jumper).

• Backplane Current Output: Delivers a continuous 5.0 Amps at 5V DC.

• User Power Output: Provides 0.96 Amps at 24V DC for external field devices and sensors.

• Input Frequency: 47–63 Hz.

• Hold-up Time: 20 ms at full load; up to 3000 ms at no load to bridge brief voltage sags.

• Safety Isolation: 1800V AC RMS for 1 second between input and backplane.

• Overcurrent Protection: Built-in fuse (Type 1746-F2) with 15A max overcurrent threshold.

• Mounting Requirements: Left-side chassis mounting; requires 1746 modular hardware.

• Operating Temperature: 0°C to 60°C (32°F to 140°F).

• Dimensions: 15.2 x 10.2 x 15.2 cm.

• Weight: 0.7 kg (1.1 kg shipping weight).

Operational Reliability and Installation

The 1746-P2 is built to maintain system integrity during fluctuating power conditions. Its significant hold-up time allows the SLC CPU to perform orderly shutdowns or maintain operation during minor power dips. In the event of an overcurrent condition, later revisions (Series C) are designed to keep the CPU active while isolating the 24V user power, preventing complete system crashes due to external field wiring faults.

For optimal longevity, it is recommended to install the unit using an isolation transformer, particularly in environments with high-inductive loads that generate significant electrical noise. The front-facing terminal strip provides clear access for line, neutral, and ground connections, facilitating rapid installation and replacement. As a critical component of the SLC 500 ecosystem, the 1746-P2 continues to support the reliable performance of legacy automation systems in sectors ranging from water treatment to automotive manufacturing.