The 1771-P4S1 Power Supply Module is an AC power module by Allen-Bradley which provides power to the backplane and is installed in a single slot of the 1771 I/O chassis. It has a nominal input voltage of 120V AC and an input current of 0.88 Ampere. Its input voltage ranges between 85 and 120V AC at 47-63Hz, and the module has a real input power of 56W, and an apparent power of 89VA. It has an output rating of 5.06V DC (+-3/6% of the total output) voltage and a maximum output current of 8A at 5V DC. It dissipates 4W heat at 2A, and 17W heat at 8A and the maximum power dissipated by the adjacent slot is 10W. The 1771-P4S1 provides tested 2160V DC isolation for 1 seconds, and a branch circuit protection for a current no greater than 15A. 

It has a Terminal Block Screw torque of 0.5Nm and is fused with a 1.5A 125V slow blow fuse, Bussman MDX 1.5, Littel fuse 31301.5, and IEC 127 Type T (blue) fuse. The 1771-P4S1 has a maximum power loss delay time of 13.6ms (-+3.6), and uses a copper conductor with 14 AWG size rated at 60 0C and with an insulation thickness of 1.2mm (max). The module has an IEC tested and rated working temperature range of 0060 0C without de-rating around a relative humidity range of 5-95% without condensation. The 1771-P4S1 weighs approximately 1.04Kg (2.3lb) and is designed with an open-style enclosure.  A recommended 140VA load transformer optional transformer may be used alongside it, and the module is UL and CSA-certified.