Product Overview
The Allen-Bradley 1771-P5E is a power supply module for the legacy 1771 programmable controller and I/O chassis platform. It converts incoming AC line power into the regulated DC voltages required by the chassis backplane, processor, and I/O modules. As a central part of the control-system power architecture, the Allen-Bradley 1771-P5E must deliver stable voltages and sufficient current to support the installed module combination under both steady-state and transient operating conditions.
The Allen-Bradley 1771-P5E is designed for use with compatible 1771 chassis and PLC-5 processors. It typically accepts 120/220 V AC input and provides 5 V DC and 24 V DC outputs for the backplane, although the exact output current and module capacity must be confirmed against the specific series and system configuration. Correct mounting position, total backplane load, chassis slot population, and ambient temperature are critical because exceeding the power-supply rating can cause erratic I/O behavior, processor faults, or unexpected system shutdowns.
For industrial plants still operating PLC-5 and 1771 equipment, the Allen-Bradley 1771-P5E remains a strategically important spare part. A failed power supply can disable an entire controller chassis, making rapid identification and replacement essential to production continuity. The module supports legacy machine control, process automation, material handling, and other applications where replacement of the complete control platform may be impractical in the short term. A tested and correctly matched Allen-Bradley 1771-P5E allows maintenance teams to restore power quickly while planning a longer-term modernization program.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 1771-P5E |
| Manufacturer | Rockwell Automation / Allen-Bradley |
| Product Type | Chassis Power Supply Module |
| Compatible Platform | 1771 I/O chassis / PLC-5 systems |
| Input Voltage | 120/220 V AC |
| Input Voltage Range | 104–132 V AC or 208–264 V AC |
| Input Frequency | 50/60 Hz |
| Inrush Current | 20 A at 120 V AC; 40 A at 220 V AC |
| 5 V DC Output | 5 A typical |
| 24 V DC Output | 0.96 A typical |
| Output Power | 50 W typical |
| Hold-Up Time | 10 ms typical at rated load |
| Status Indication | OK LED and fault indication |
| Mounting Position | Rightmost or left-capable position, chassis dependent |
| Module Width | One 1771 chassis slot |
| Chassis Power Rating | 5 A at 5 V DC; 2 A at 24 V DC |
| Operating Temperature | 0–60 °C |
| Storage Temperature | −40–85 °C |
| Relative Humidity | 5–95%, non-condensing |
| Shock | 30 g peak, 11 ms duration |
| Vibration | 5–2000 Hz, 3 g peak |
| Country of Origin | United States |
Main Features and Advantages
Stable regulated power for legacy control systems: The Allen-Bradley 1771-P5E provides regulated 5 V DC and 24 V DC outputs to the 1771 backplane. Stable voltages are essential for processor operation, digital and analog I/O, communication modules, and specialty modules. Voltage instability or insufficient current can produce faults that are difficult to distinguish from failed I/O, damaged field devices, or software errors.
High inrush-current handling: When first energized, the Allen-Bradley 1771-P5E can draw 20 A at 120 V AC or 40 A at 220 V AC during the initial charging period. This capability supports the connected capacitive and inductive load of the chassis, but it also means that upstream protection devices and wiring must be sized correctly. Failure to account for inrush current can result in nuisance breaker tripping or contact damage.
Built-in diagnostics and serviceability: The module includes an OK status LED and fault indication that help technicians determine whether the power supply is operating within specification. Combined with voltage checks and a review of the backplane load, these indicators can shorten troubleshooting time. Because the Allen-Bradley 1771-P5E occupies one chassis slot and uses the standard 1771 mechanical interface, it can be replaced quickly when a tested spare is available.
Legacy system availability and lifecycle value: PLC-5 and 1771 systems remain in service in many heavy-industrial, process, and discrete-manufacturing applications. The Allen-Bradley 1771-P5E helps extend the service life of these systems by providing a critical power component that may no longer be readily available through standard distribution channels. Its value is highest when the module has been inspected, tested, and documented as part of a managed spare-parts program.
