Introduction
In the late 1990s, factory floors began replacing centralized control panels with distributed I/O racks. Engineers needed a compact, reliable way to power those racks without running separate supplies to every module. The Allen-Bradley 1769-PB2 answered that call. As a dedicated I/O power supply for the CompactLogix platform, it sits between your 24VDC source and the I/O modules, delivering clean, regulated power to both sides of the rack. This module supports up to sixteen CompactLogix modules, making it a cornerstone of modular control architectures. Whether you are upgrading a legacy system or building a new panel, the 1769-PB2 provides the stable foundation your I/O needs.
What Makes the 1769-PB2 a Smart Replacement Choice
When an existing power supply fails, downtime costs climb by the minute. The 1769-PB2 offers a direct drop-in solution for CompactLogix racks that require a 24VDC input. Its wide input voltage range of 19.2–31.2 VDC tolerates the fluctuations common in industrial power networks. You get 2.0 A at 5VDC and 0.8 A at 24VDC, enough to energize a full complement of I/O modules. The power supply distance rating of 8 means you can place up to eight modules on each side, simplifying wiring and reducing cabinet footprint. With built-in fuse protection and finger-safe covers, this module prioritizes safety without sacrificing ease of installation.
Technical Specifications That Matter
Understanding the key parameters helps you match the 1769-PB2 to your application. The table below summarizes the most critical ratings.
| Specification | Value |
|---|---|
| Input Voltage Range | 19.2–31.2 VDC |
| Current Capacity @ 5VDC | 2.0 A |
| Current Capacity @ 24VDC | 0.8 A |
| Max Inrush Current | 30 A @ 31.2 VDC |
| Power Consumption | 7.5 W @ 60 °C (140 °F) |
| Fuse Type | Littelfuse 02153.15MXP; Wickmann 19195-3.15A |
| Wire Size | 14 AWG (2.5 mm²) solid copper, 90 °C or greater |
| Certifications | c-UL-us; CE; C-Tick |
| Weight | 485 g (1.07 lb) |
| Dimensions (HxWxD) | 118 x 70 x 87 mm (4.65 x 2.76 x 3.43 in.) |
The 7.5 W power consumption at 60 °C indicates efficient operation with minimal heat generation. The 30 A inrush current rating ensures the module can handle startup surges without tripping upstream protection. These specs translate to reliable performance in demanding environments.
Where the 1769-PB2 Excels
This power supply fits seamlessly into several industrial scenarios. In automotive assembly lines, CompactLogix racks control robots and conveyors. The 1769-PB2 powers digital and analog I/O modules that interface with sensors and actuators. Its wide input range handles voltage sags caused by welding equipment. In food and beverage plants, the module’s open enclosure requires mounting inside a protective cabinet, but its robust design withstands washdown environments when properly enclosed. For water treatment facilities, the 1769-PB2 provides dependable power for remote I/O drops, thanks to its tolerance of temperature extremes from 32 to 140 °F. Each application benefits from the module’s ability to support up to sixteen modules, reducing the number of separate power supplies needed.
Installation and Setup Guidelines
Mounting the 1769-PB2 follows standard CompactLogix practices. You can attach it directly to a panel or snap it onto a DIN rail. Use 14 AWG solid copper wire rated for 90 °C or higher. Keep insulation thickness to 1.2 mm maximum. The module includes printed terminal diagrams and barrier-style terminal blocks for secure connections. Always verify polarity before applying power. The finger-safe covers protect against accidental contact. Remember that the open enclosure requires installation inside a larger cabinet that shields against dust and moisture. For best results, maintain the specified clearance around the module for airflow.
Maintenance and Reliability
The 1769-PB2 has no moving parts, so wear is minimal. Periodically inspect terminal connections for tightness and look for signs of overheating. Check the fuse if the module stops delivering power; replace only with the specified Littelfuse 02153.15MXP or Wickmann 19195-3.15A. Keep the surrounding environment within the operating temperature range of 32 to 140 °F and humidity between 5 and 95% non-condensing. Following these simple steps ensures years of reliable service. Because the module supports hot-swap in many CompactLogix systems, you can replace a failed unit quickly, minimizing downtime and protecting your ROI.
Compatibility and Integration
The 1769-PB2 integrates directly with Allen-Bradley CompactLogix controllers and I/O modules. It communicates no data itself; it simply provides power. You can use it in a local rack or an expansion bank. The module works with both Series A and B hardware. Its 24VDC input matches common industrial power supplies, so you can source power from a central 24VDC bus. When planning your system, confirm that your controller and I/O modules are compatible with the 1769 platform. SpareTechPLC stocks genuine Allen-Bradley components to keep your system running.
Selection Guide
Before ordering a 1769-PB2, verify your input voltage is within 19.2–31.2 VDC. Calculate your total current draw at 5VDC and 24VDC to ensure the module’s capacity meets your needs. Remember the distance rating of 8: you can place up to eight modules on each side. If you need more, consider additional power supplies. Check that your wiring meets the 14 AWG specification. For replacement parts, SpareTechPLC offers fast shipping and expert support. Contact us to confirm availability and compatibility with your existing setup.
Frequently Asked Questions
What is the input voltage range of the 1769-PB2?
The 1769-PB2 accepts 19.2–31.2 VDC, with a nominal input of 24 VDC.
How many I/O modules can the 1769-PB2 power?
It can power up to sixteen modules: eight on each side, thanks to its distance rating of 8.
What fuse does the 1769-PB2 use?
It uses a Littelfuse 02153.15MXP or Wickmann 19195-3.15A fuse.
Can I mount the 1769-PB2 on a DIN rail?
Yes, it supports both panel mounting and DIN rail mounting.
What certifications does the 1769-PB2 hold?
It is certified c-UL-us, CE, and C-Tick.
