ALLEN BRADLEY 1746-P2 Product Description

Overview

ALLEN BRADLEY 1746-P2 is an SLC 500 rack-mount power supply for the Allen-Bradley SLC modular PLC chassis. The supply provides the internal DC power required by the SLC processor, rack backplane and installed I/O modules. The Rockwell product description identifies it as a 120/240 V AC, 5 A SLC system power supply mounted in the chassis power-supply slot. The 1746-P2 is a legacy SLC 500 power supply, listed by Rockwell as discontinued with no planned Rockwell replacement, and traded as a replacement spare for existing SLC installations.

Features

1746-P2 accepts a line voltage of 85 to 132 V AC or 170 to 265 V AC, at 47 to 63 Hz. Typical line power requirement is 180 VA, and maximum inrush current is 45 A. Internal current capacity is 5 A at 5 V DC and 0.96 A at 24 V DC for the SLC backplane. Fuse protection uses the 1746-F2 fuse or equivalent.

The power supply does not provide an external 24 V DC user-power output on the 1746-P2 version according to the SLC power supply specification. Ambient operating temperature is 0 to 60 degrees Celsius, with no derating listed for the P2 supply over that range. Isolation between input terminals and backplane is 600 V AC RMS for 1 second on version B or later. CPU hold-up time is 5 ms at full load and 1000 ms at no load.

The supply is installed in the left-side card guides of the SLC chassis and fastened to the chassis. An input voltage jumper must be set to match the line voltage before applying power. Input wiring uses #14 AWG copper wire, with terminal screws tightened to 0.8 Nm or 7 lb-in, and the power supply fastening screws tightened to maximum 1.2 Nm or 11 lb-in. Rockwell lists country of origin as Malaysia, product depth as approximately 140 mm, and catalog dimensions for the P2 supply at approximately 85 mm length.

Specs

Brand: ALLEN BRADLEY, Rockwell Automation System: SLC 500 modular PLC chassis Model: 1746-P2Product type: Rack-mount chassis power supply Line voltage: 85 to 132 V AC or 170 to 265 V ACLine frequency: 47 to 63 HzTypical line power: 180 VAMaximum inrush current: 45 AInternal current capacity: 5 A at 5 V DC; 0.96 A at 24 V DCFuse protection: 1746-F2 or equivalent External 24 V DC user power: Not applicable on 1746-P2 Operating ambient temperature: 0 to 60 degrees CelsiusIsolation: 600 V AC RMS for 1 s, version B or later, input to backplane CPU hold-up time: 5 ms full load; 1000 ms no load Mounting: SLC chassis power-supply slot, left-side card guides Input jumper: Required to match line voltage before power-up Input wiring: #14 AWG copper; terminal torque 0.8 Nm, 7 lb-inMounting screw torque: Maximum 1.2 Nm, 11 lb-inApproximate depth: 140 mm, 5.70 inApproximate length: 85 mm, 3.35 inCountry of origin: MalaysiaProduct status: Rockwell discontinued legacy SLC 500 power supply; replacement spare for existing SLC installations

Principle

The 1746-P2 converts the supplied AC line voltage into the regulated DC voltages required by the SLC 500 rack: 5 V DC for logic and backplane electronics, and 24 V DC for internal rack and module requirements. The supply distributes this power through the SLC chassis backplane to the processor and I/O modules installed in the chassis slots. Internal current capacity limits must be respected when adding processor, communication, analog, digital and specialty modules.

When line voltage drops below the operating range, the SLC controller continues scanning and controlling I/O for the short CPU hold-up period before stopping if the supply remains out of range. The fuse protects against fire hazard caused by short-circuit conditions, but may not protect against miswiring or excessive line transients. Because inductive loads such as motors, starters, solenoids and relays can generate voltage surges, an isolation transformer is recommended where these loads are connected near the supply. Replacement should verify input voltage jumper setting, chassis slot, ground connection, backplane load, total module current, fuse condition and SLC chassis revision before commissioning.

Applications

ALLEN BRADLEY 1746-P2 is used to power legacy Allen-Bradley SLC 500 PLC racks in industrial machinery, production lines, conveyor systems, packaging machines, material handling, pumps and fans, compressors, machine tools, process equipment, utilities, water and wastewater, chemical and process plants, and general automation control panels. It supplies the processor and I/O modules in existing SLC chassis installations. In SLC systems originally equipped with the P2 supply, it serves as a direct replacement rack-mount power spare matched to the original chassis, voltage configuration and installed module load.