Purchase now: Allen Bradley 1746-P2 SLC 500 Power Supply
Purchase now: Atlantechdrives provides you the 1746-P2, a robust and highly dependable chassis-mounted power supply designed by Allen Bradley for the widely deployed SLC 500 automation platform. Acting as the electrical backbone of the PLC, the 1746-P2 takes incoming AC line voltage and meticulously regulates it into the precise 5V DC and 24V DC backplane currents required by the processor and the associated I/O modules. While the baseline P1 model is sufficient for small 4-slot racks, the 1746-P2 delivers a significantly upgraded 5.0 Amps at 5V DC, making it the industry standard choice for medium-sized 7-slot or 10-slot chassis loaded with multiple analog or high-density digital modules.
Technical Specifications of the 1746-P2
The 1746-P2 power supply is engineered to endure harsh industrial environments, featuring built-in overcurrent protection and robust hold-up times to ride out minor AC brownouts without crashing the PLC logic. It mounts directly onto the left end of any standard 1746 chassis.
- Part Number: 1746-P2
- Component Type: System Power Supply
- Compatible System: Allen Bradley SLC 500 (1746 Chassis)
- Input Voltage (Selectable): 85…132V AC or 170…265V AC
- Input Frequency: 47…63 Hz
- Backplane Output Capacity (5V DC): 5.0 Amps
- Backplane Output Capacity (24V DC): 0.96 Amps
- User 24V DC Power: Isolated external supply block (200 mA capacity)
- Inrush Current: 20A maximum
Expert Installation Advice: The 120V / 240V Jumper Switch
A simple oversight during installation can instantly destroy this expensive unit. Expert Tip: The 1746-P2 does not feature an auto-sensing AC input. Instead, it relies on a physical, red plastic jumper switch located on the internal circuit board (visible from the rear before mounting). Out of the box, or when purchased from surplus, this jumper is often set to the 120V AC position. If you install this in a plant that utilizes 240V AC control power and you fail to move the jumper to the 240V position, the moment you flip the main breaker, the internal primary transformer will catastrophically blow. Always visually verify the jumper’s physical position against your wiring schematics before sliding the unit into the chassis.
Maintenance and Power Budgeting
When upgrading a legacy machine by adding new communication cards or analog inputs, you must calculate your total backplane power draw. Even though the 1746-P2 provides 5.0 Amps, filling a 10-slot rack with power-hungry modules can exceed this limit, causing the processor to enter a fault state and shut down the machine. Always consult the Allen Bradley power budgeting worksheets before adding hardware. Additionally, inspect the internal slow-blow fuse periodically; repeated blowing indicates a hard short on the backplane.
Frequently Asked Questions (FAQs)
Q: Can I use the «User Power» terminals to power all my sensors?
A: No. The 24V DC User Power terminals on the front of the 1746-P2 only provide up to 200 mA of current. This is enough for a handful of photoelectric sensors, but it is not sufficient to power solenoid valves or large sensor arrays. You will need a separate DIN-rail power supply for heavy field loads.
Q: Will the 1746-P2 fit in any size chassis?
A: Yes, it is fully compatible with the 4-slot, 7-slot, 10-slot, and 13-slot SLC 500 chassis.
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For higher I/O densities, this robust supply is required to power high-performance units like the SLC 5/04 controller.
