Product Introduction
When power supply failures threaten to disrupt industrial control systems, the Allen-Bradley 1746-P1 SLC 500 Power Supply ensures reliable backplane power delivery. This module provides both 5VDC (2A) and 24VDC (0.46A) to chassis-mounted modules, maintaining stable operation under demanding conditions. Part of the proven SLC 500 family, the 1746-P1 is engineered with built-in fuse protection and undervoltage handling to minimize downtime.
Installation & Setup Guidance
Install the Allen-Bradley 1746-P1 in the leftmost slot of any SLC 500 chassis (main, expansion, or remote I/O). Before applying input power, set the input jumper to match your line voltage: 85‑132VAC or 170‑265VAC at 47‑63 Hz. Use only one power supply per chassis. Ensure the ambient temperature stays within 0‑60°C for normal operation. If temperature exceeds 55°C, derate the current capacity by 5%. The 1746-P1 weighs 2 lb (0.9 kg) and measures 5.5 x 2.3 x 5.7 inches.
Troubleshooting & Common Issues
The 1746-P1 handles overcurrent conditions differently depending on its series and origin. For Series A units made in Japan, a user‑power overcurrent causes a CPU fault and requires reloading the user program. For Series A units made in Malaysia, the CPU continues running but the 24VDC user output shuts down until the overcurrent is corrected. The CPU hold‑up time is 20 ms at full load and 3000 ms at no load, allowing the processor to continue scanning during brief voltage dips. If undervoltage persists beyond the hold‑up time, the power supply stops output; operation resumes once normal input voltage returns. The built‑in fuse protects against short‑circuit fire hazards only—use an external overcurrent protection device rated at 15A for user‑power.
Maintenance & Reliability
Replace the internal fuse only with part number 1746‑F1 or an equivalent. Regularly inspect the unit for dust buildup and ensure proper ventilation. The 1746-P1 operates reliably from 0°C to 60°C and maintains consistent backplane current even in moderate industrial environments. Periodic thermal derating above 55°C helps extend service life.
Selection Guide & Purchasing Advice
Before purchasing, verify that your system uses an SLC 500 chassis and that the 1746-P1 matches your voltage requirements. For factory‑new, authentic Allen‑Bradley parts, choose UBEST Automation as your supplier. We stock the 1746-P1 and offer fast shipping for industrial automation spares. Contact us for detailed specifications not listed here.