The 1746-P4 is an SLC 500 Power Supply by Allen-Bradley and Rockwell Automation. It has a line voltage of 85...132/170...250 Volts AC at 47-63 Hertz and a typical line power requirement of 150 Volt-amperes. Maximum inrush current for the 1746-P4 is 45 Amperes and it has an internal current capacity of 10.0 Amperes at 5 Volts DC and 2.88 Amperes at 24 Volts DC. Fuse protection is capable by being soldered into place. The 1746-P4 has a 24 Volt DC user-power current capacity of 1 Ampere and a 24 Volt DC user-power voltage range between 20.4...27.6 Volts DC. Maximum user-supplied overcurrent protection is 15 Amperes and it has an ambient operating temperature ranging between 0 and 60 degrees Celsius (32 to 140 degrees Fahrenheit) with no derating. The 1746-P4 has an isolation of 2600 Volts DC for 1 second and a CPU hold-up time of 20 milliseconds at full load and 3000 milliseconds at no load.

The manufacturer gives detailed information on installation of the power supply; when installing the 1746-P4, the installer must first align the circuit board of the power supply with the card guides on the leftmost side of the 1746-P4 chassis. Next, slide the 1746-P4 power supply into the chassis until it is flush with it; fasten the power supply to the chassis. When wiring the 1746-P4 power supply, first place the input voltage jumper to match the input voltage; after this is complete, connect the ground screw of the power supply to the closest ground/ground bus. Use a 1.68 millimeter, 75 degree copper wire and keep the leads as short as possible. For more information on installing and wiring this 1746-P4 Power Supply, refer to the Allen-Bradley/Rockwell Automation user and installation manual.

As of note, the SLC 500 Power Supplies have a hold-up mode. These power supplies operate in hold-up mode for a short time when the input voltage of the power supply drops below the recommended voltage range for operation, or in other terms, if the power supply is undervoltage. This line of power supply will turn off if the input voltage is dropped or removed from the power supply and automatically resumes once the input voltage is restored. Additionally, the CPU hold-up time for this power supply at full load is twenty milliseconds (20 ms) and three thousand milliseconds (3000 ms) for no load. The Allen-Bradley 1746-P4 may also, in its life, have an overcurrent condition. In the event that the 1746-P4 goes into an overcurrent condition, the power supply of the device will shut down and there will be a CPU fault. In order to fix this problem, all one needs to do is reload the user program, and the device is ready to go again. 

The physical dimensions of the Allen-Bradley 1746-P4 measure out to 110 mm x 145 mm x 140 mm (4.33 in. x 5.70 in. x 5.51 in.). The Allen-Bradley 1746-P4 also has many certifications to its name. These certifications include UL Listed Industrial Control Equipment and CSA Certified Process Control Equipment for Class 1, Div. 2, Groups A, B, C, and D Hazardous Locations. This product is intended to be used in a Pollution Degree 2 industrial environment. Do not use this product at an altitude that is above two thousand (2000) meters, or 6561 (six thousand five hundred and sixty-one) feet, without derating.