1769-PA4 CompactLogix Power Supply – Installation and Technical Guide
Product Introduction
The Allen‑Bradley 1769‑PA4 serves as the primary power source for CompactLogix controller systems. This module accepts a wide AC input range from 85 to 265 VAC, switch‑selectable for 120V or 220V operation. It delivers 4.0A at 5V DC and 2.0A at 24V DC to power the controller and connected I/O modules. The 1769‑PA4 mounts directly on a DIN rail or panel, integrating seamlessly into the 1769 Compact I/O platform.
Core Value
This power supply simplifies system design by providing reliable, regulated DC power for the CompactLogix backplane. Specifically, the 1769‑PA4 supports up to eight I/O modules on each side, for a maximum of sixteen modules total. Moreover, the wide input voltage range allows global deployment without voltage selection concerns. Furthermore, the module includes built‑in fuse protection and status LEDs for immediate visual diagnostics. Besides that, the 1769‑PA4 delivers 24V DC user power for sensors or other field devices, reducing the need for separate power supplies. Therefore, you gain both cost savings and panel space efficiency.
Technical Insights
Firstly, the 1769‑PA4 operates at 47‑63 Hz input frequency with a maximum inrush current of 25A at 132V AC. Secondly, the module dissipates up to 18W of heat at 60°C, so proper ventilation is essential. Additionally, the reinforced insulation provides 265V continuous isolation, routine‑tested at 2596V DC for one second. Meanwhile, the internal fuse type is Wickmann 19195‑3.15A or Littelfuse 02183.15MXP. Specifically, the power supply distance rating is eight modules per side; exceeding this limit prevents the backplane from recognizing additional hardware. Therefore, always plan your I/O layout within this architectural constraint.
Installation & Maintenance
Begin by mounting the 1769‑PA4 on a standard 35 x 7.5mm DIN rail or using M4 screws for panel mounting. Next, connect the AC wiring to the L1 and L2 terminals, and securely fasten the chassis ground screw to the nearest ground bus. After wiring, verify the voltage selector switch matches your supply voltage before powering on. For routine maintenance, we recommend inspecting terminal connections every six months for tightness and corrosion. Besides that, periodically check the LED indicators; a steady green light confirms normal operation. If the module fails to power up, first check the internal fuse. Replace it only after removing power and correcting the fault condition. Always use the recommended 14 AWG solid copper wire rated at 90°C.
Buyer's Guide FAQ
Q1: Which controllers are compatible with the Allen‑Bradley 1769‑PA4?
A: The 1769‑PA4 works with CompactLogix 1769‑L3x and 1769‑L2x controllers that require external power. It does not support MicroLogix 1500 systems with embedded power supplies unless using an expansion cable.
Q2: How many I/O modules can the 1769‑PA4 support?
A: The 1769‑PA4 supports up to eight I/O modules per side, totaling sixteen modules maximum. This limit is a backplane communication constraint, not purely a power capacity issue.
Q3: What is the output current capacity of the 1769‑PA4?
A: The module delivers 4.0A at 5V DC and 2.0A at 24V DC. Always calculate the total current draw of your I/O modules to avoid exceeding these limits.
Q4: Can I use two 1769‑PA4 modules to power more than sixteen I/O modules?
A: No. You cannot daisy‑chain local 1769 backplanes to increase the module count. For more than eight modules per bank, use an EtherNet/IP adapter like the 1769‑AENTR for expansion.
Q5: What does the LED indicate on the 1769‑PA4?
A: A steady green LED indicates normal operation. If the LED is off, check input power, fuse integrity, and backplane connection. Flashing or amber lights are not applicable to this module.
