The 1746-P2 power supply is a modular power unit developed by Allen‑Bradley and used within the 500 controller platform from Rockwell Automation. It is designed to provide stable operating power for the SLC 500 PLC rack and its installed I/O modules. The 1746-P2 was developed to support larger SLC 500 configurations, offering higher output capacity and a flexible input voltage range.
1746-P2 distributes power to each module through the backplane of the PLC rack. After installation, the power module will automatically supply power to the following devices:
SLC 500 CPU Processor
I/O Module
Communication module
Special Function Module
With the development of automation technology, the SLC 500 series has gradually been replaced by the new generation of PLC systems, such as:
ControlLogix
CompactLogix
Technical Information
|
Manufacture |
Allen Bradley |
|
Model |
1746-P2 |
|
Description |
SLC 500 PLC Rack Power Supply |
| Installation location | Side of the 1746 series PLC rack |
|
Origin |
USA |
|
Dimension |
20*20*18cm |
|
Weight |
0.8kg |
Why choose the 1746-P2 Power Supply?
Compared with the smaller power modules in the same series, the 1746-P2 Power Supply provides a higher current output. Its 5V DC output can reach up to 5A, which allows the rack to support more I/O modules or additional expansion racks. This makes it suitable for control systems where the PLC needs to handle a large number of field signals.
The 1746-P2 Power Supply can work with both 110V and 220V AC power sources. By adjusting the internal jumper setting, the same power supply can be used in different regions without changing the model. For equipment that may be installed in different countries or exported to overseas projects, this simplifies inventory and maintenance.
Besides powering the PLC backplane, the 1746-P2 also provides a 24V DC auxiliary output with a capacity of 200 mA. This can be used to supply small field devices such as sensors or switches. In many control cabinets, this eliminates the need for a separate small power supply and helps keep wiring simpler.
The 1746-P2 Power Supply includes a brief hold-up time of around 20 milliseconds at full load. This means a very short power disturbance will usually not shut down the PLC immediately. For production equipment where unexpected stops can cause losses, even a short buffer time can help maintain system stability.
Use the power module.
Dedicated Power Slot in the Rack
The 1746-P2 Power Supply is installed in the power supply slot at the far left side of the rack, rather than occupying an I/O slot. This keeps the addressing of I/O modules consistent and makes system configuration easier during installation and programming.
The unit is designed to operate within a 0–60°C temperature range. Even when cabinet temperatures rise during summer operation, the power supply can still function with only a slight reduction in output capacity. In many cases, additional cabinet cooling equipment is not necessary.
Proper grounding of the rack is recommended, usually with a resistance below 4 ohms. This helps reduce electrical noise, which can be important when the PLC system is installed close to large motors, drives, or other high-power equipment.
System installation & Typical application scenarios
1746-P2 is installed in a modular rack and is designed for the SLC 500 PLC system.
The installation process usually consists of:
Turn off the power supply of the PLC system
Install the power module on the left side of the rack.
Connect the AC input power supply
Check for grounding
Power-on test
After the installation is completed, the power module will automatically supply power to the system module through the backplane.
This module supports:
4-slot rack
7-slot rack
10-slot rack
13-slot rack
Manufacturing automation:
Production line control system
Packaging machinery, printing equipment, textile machinery
Robot workstations
Process control:
Chemical, petroleum, and natural gas industries
Water treatment and sewage treatment systems
Food and beverage processing
Infrastructure:
Building automation (HVAC)
Traffic Signal Control Energy Management System
FAQ
Q: 1746-P2 power supply occupies the SLC 500 rack slot?
A: It does not occupy a slot. It is installed on the left side of the rack and is not included in the total number of I/O slots.
Q: What is the operating temperature range of 1746-P2?
A: The working environment temperature ranges from 0°C to +60°C.
Q: Is 1746-P2 still officially manufactured by Allen-Bradley?
A: This product has been officially marked as "Discontinued" and will cease production in 2024.
Q: Was there an official alternative model after the 1746-P2 model was discontinued?
A: At present, there is no officially designated direct replacement model. However, we have a large quantity of spare parts in stock for selection, which can ensure that the user's equipment operates for a long time.