Allen-Bradley 1771-P7B Power Supply 120/240 VAC

The Allen-Bradley 1771-P7B external power supply provides a regulated 5.1 V DC output to power a single 1771 I/O chassis in PLC‑5 systems when the I/O rack does not include an internal supply. It accepts 120 V AC or 220/240 V AC input (auto-selecting with nominal input currents around 0.75 A at 120 V or 0.38 A at 240 V; 60/50 Hz) and delivers up to 6.5 A at 5.1 V DC (approximately 32 W) with a regulation tolerance of ±5%. The unit is designed for left-side mounting in the 1771 I/O chassis or within about 5 cable-feet from the I/O rack, weighs roughly 5.89 kg (13 lb), and measures 11.6 cm (4.56 in) wide, 28.6 cm (11.25 in) high, and 18.2 cm (7.16 in) deep. Electrical isolation between input and output is rated at 2,500 V DC for 1 second, supporting safe operation in industrial environments. Fusing varies by input voltage: 1 A, 3AG slow-blow for 120 V operation and 0.5 A, 3AG slow-blow for 220–240 V operation. The 1771-P7B is capable of powering a single 1771-A1B, -A2B, -A3B, -A3B1, or -A4B I/O chassis when used with an appropriate adapter or PLC that lacks an internal power supply.