Allen Bradley 1746-P2

Our company has specially prepared a key power supply unit for overseas industrial automation engineers. As those who have dealt with PLC systems know, no matter how good the CPU is or how many modules there are, if there is no reliable power supply to power them, the entire system is just a decoration. Feimu Technology, as a professional spare parts supplier, recommends this high-power and highly stable power module to everyone, in order to ensure that when the system is operating at full capacity, there will be no concerns about unstable voltage or power failure, and the equipment in the cabinet will always have sufficient power.

Product Application

This Allen Bradley 1746-P2 power module is used in an extremely wide range of applications. The most common ones include the control systems of large machining centers, the main control cabinets of food packaging lines, and the pump stations of water treatment plants. As long as it is a SLC 500 system with a large number of modules installed and high current consumption, this power module is definitely the first choice. It is the energy source that powers the entire cabinet.

How is the performance?

This 1746-P2 power module performs extremely well, being "powerful and reliable". Its input voltage range is wide, capable of accommodating 85 to 265 volts of alternating current. Whether it's a 110V system or a 220V power grid, it can be plugged in and used immediately. The most crucial aspect is that its output ripple is extremely small, and the output DC 5V and 24V are very clean, without interfering with those precise modules. Moreover, its response speed is extremely fast. As soon as the load increases, it can immediately adjust the output voltage to ensure no power loss, which is extremely important for those production lines that cannot be shut down.

How to maintain?

The maintenance of this Allen Bradley 1746-P2 power module is not difficult. It should be kept in the cabinet at all times. The most important things are dust prevention and ventilation. Make sure not to block its ventilation holes. Otherwise, if the temperature is too high, the capacitors may explode. Also, regularly use a hair dryer to blow away the dust inside to keep it clean. If it is not used for a long time, it is recommended to unplug it and put it in an anti-static bag, and store it in a constant-temperature and dry cabinet. The most important point is that when connecting the wires, you must clearly distinguish the live wire, neutral wire and ground wire. Never directly connect the 220V to the output terminals. Otherwise, it will be damaged as soon as it is powered on.

Correct Product Specifications

The Allen Bradley 1746-P2 is a power supply module designed specifically for the SLC 500 system. It provides DC power to the backplane and connected modules.

Input specifications:

Input voltage: 85-265V AC, 47-63Hz

Input current: 2.5A maximum at 115V AC, 1.2A at 230V AC

Inrush current: 20A maximum at 115V AC, 40A at 230V AC (cold start)

Output specifications:

Output 1: 5V DC at 8A maximum

Output 2: 24V DC at 0.5A maximum (for analog modules or field devices)

Maximum combined output: 35W at 60°C

Hold-up time: 15ms minimum (at full load)

Output ripple: Less than 50mV peak-to-peak for 5V, less than 100mV for 24V

Efficiency: 75% typical at full load

General specifications:

Protection: Overvoltage protection, short circuit protection, thermal shutdown

Operating temperature: 0°C to 60°C

Storage temperature: -40°C to 85°C

Relative humidity: 5% to 95% (non-condensing)

Mounting: Chassis slot 0 only

Certifications: UL, cUL, CE

Power Budget Calculation

The 1746-P2 provides 8A of 5V DC power. Each module in the SLC 500 chassis draws a specific amount of 5V current. Use this guide to calculate your system's power consumption.

Backplane current draw for common modules:

- 1746-IA16 (digital input): 60mA

- 1746-OW16 (relay output): 100mA

- 1746-OBP16 (triac output): 85mA

- 1746-NI4 (analog input): 150mA

- 1746-NO8V (analog output): 200mA

- 1746-IO4 (combo analog): 150mA

- 1747-L552 (CPU): 500mA

- 1747-L532 (CPU): 400mA

Total 5V current draw: Add all module currents together. Include the CPU and any communication modules.

Example calculation:

CPU: 500mA

Module 1: 60mA

Module 2: 60mA

Module 3: 100mA

Module 4: 150mA

Total: 870mA

The 1746-P2 provides 8A (8000mA). This system uses only 870mA. There is plenty of spare capacity.

When to upgrade to a larger power supply:

If the total 5V current exceeds 8A, you must either reduce the number of modules or add a second power supply chassis. Most SLC 500 systems use less than 4A. The 1746-P2 is sufficient for most applications. For systems with more than 10 modules or multiple analog modules, calculate the total before ordering.

Common field issue: A customer added 4 analog output modules to their system without recalculating power. The total current exceeded 8A. The system randomly reset during peak operation. Fix: Removed two analog modules and used a remote I/O rack with its own power supply. The problem disappeared.

Installation and Clearance Requirements

The Allen Bradley 1746-P2 occupies slot 0 in the SLC 500 chassis. This is the only slot that supports the power supply. Correct installation ensures proper airflow and cooling.

Installation steps:

1. Turn off all power to the chassis.

2. Remove the filler plate from slot 0.

3. Slide the power module into the slot.

4. Push until the top and bottom latches click.

5. Connect the AC power cord to the module.

6. Connect the ground wire to the chassis ground terminal.

7. Turn on the AC power. The Power LED should turn on.

Clearance requirements:

Top clearance: 10cm minimum above the module for airflow

Bottom clearance: 5cm minimum below the module

Side clearance: 2cm minimum on each side

Front clearance: 15cm minimum in front of the module for ventilation

Heat dissipation:

The 1746-P2 dissipates up to 15W of heat at full load. This heat must be removed from the enclosure. If the cabinet temperature exceeds 60°C, the module may shut down or fail prematurely. Use a cooling fan if the cabinet is sealed or has limited airflow.

What happens if clearance is ignored: The module overheats. The output voltage drops. The system resets unpredictably. The capacitors have a shortened life. In severe cases, the module fails completely. Always maintain recommended clearances.

Power LED Status and Troubleshooting

The 1746-P2 has one LED indicator on the front panel. It indicates the power status of the module.

Power LED (green): On when the module is supplying correct output voltages. Off when no AC power is present or the module has failed.

Troubleshooting checklist:

If the Power LED is off:

- Check that the AC power cord is plugged in.

- Check that the AC power source is live (85-265V AC).

- Check that the input fuse is not blown. The fuse is located on the front panel of the module.

- Check that the module is fully inserted into slot 0.

- Check that the latches are locked.

If the Power LED is on but the CPU does not start:

- Check that the CPU is inserted correctly in slot 1.

- Check that the backplane connector on the power supply is clean.

- Remove all other modules. Test with only the CPU and power supply.

- If the CPU starts without other modules, one module is drawing too much current. Add modules one by one to find the problem.

If the Power LED flickers or dims:

- The AC input voltage may be unstable. Check the grid voltage.

- The load may be exceeding the maximum output current. Remove modules to reduce load.

- Internal component failure. Replace the module.

What Feimu does before shipping: Every 1746-P2 is tested with an SLC 500 chassis. The output voltage is measured at 5V and 24V under load. The ripple is measured to ensure it is within specification. The module runs through a 24-hour burn-in test. This identifies early failures before the module reaches you.

Product Authenticity Verification

Allen Bradley 1746-P2 power modules are widely counterfeited. Use these five checks to verify authenticity.

1. Front panel color: Genuine modules have a specific olive-green color with a matte finish. Counterfeits often use the wrong shade or a glossy surface.

2. Input connector: Genuine modules use a heavy-duty AC power connector. The connector is securely attached to the panel. Counterfeit connectors are often loose or made of lower quality plastic.

3. Fuse holder: The fuse holder on the front panel of genuine modules is labeled with the fuse rating. The label is permanent. Counterfeit labels often peel or are missing.

4. Module weight: Genuine 1746-P2 weighs approximately 0.6 kg. The heavy transformer and heat sink give it weight. Counterfeits feel lighter due to smaller transformers and cheaper components.

5. Packaging: Genuine packaging has the Rockwell Automation logo on high-quality cardboard. Counterfeit packaging uses thinner cardboard and poor print quality.

If you suspect a counterfeit: Do not install. Contact Feimu Technology with photos. We verify within 2 hours. All modules supplied by Feimu pass these five checks before shipment.

Supplier Background and Service Commitment

Feimu Technology operates from Jiangmen City, Guangdong Province, China. The company was founded in 2005 and has supplied automation components to customers in over 30 countries.

Years in operation: 20 years as of 2025.

Warehouse: 2000+ square meters. Temperature controlled. Humidity maintained below 60%.

Inventory: 5000+ active SKUs. Includes SLC 500 power supplies, PLC modules, ControlLogix, CompactLogix, POINT I/O, PanelView HMIs, and drives.

Brands carried: Allen Bradley, Siemens, GE, Schneider.

Export markets: Europe, North America, South America, Middle East, Southeast Asia. Over 30 countries.

Testing for 1746-P2:

- Visual inspection for panel color and connector condition.

- AC input voltage range test: 85V, 115V, 230V, 265V tested.

- 5V output test: 5.00V ± 2% at 8A load. Verified.

- 24V output test: 24.00V ± 5% at 0.5A load. Verified.

- Ripple test: 5V output ripple measured below 50mV peak-to-peak. Verified.

- Hold-up time test: Minimum 15ms at full load. Verified.

- 24-hour burn-in test: Module runs at 60°C ambient. Outputs checked for stability.

Warranty: 12 months from shipment date. Covers manufacturing defects and component failure. Does not cover wiring errors, overvoltage damage, water damage, or physical impact. Defective modules are replaced.