Allen Bradley 12 To 120V AC Output Module 1771-OAD REM

Allen-Bradley 1771-OAD Digital AC Output Module

The Allen-Bradley 1771-OAD is a 16-point digital AC output module designed for use within the PLC-5 series, providing reliable control over AC-powered devices in industrial automation systems.

Key Features

• Number of Outputs: 16
• Operating Voltage Range: 10 to 138 V AC at 47–63 Hz
• Output Current Rating: 2 A per output, with a maximum of 8 A per module
• Surge Current: 25 A per output for 100 ms, repeatable every 1 second
• Minimum Load Current: 5 mA per output
• On-State Voltage Drop: Maximum of 1.5 V at load currents greater than 50 mA
• Off-State Leakage Current: Maximum of 3.0 mA per output at 138 V AC
• Signal Delay: Zero crossing 8.3 ms at 60 Hz, 10.0 ms at 50 Hz
• Power Dissipation: 13 W maximum, 1.5 W minimum
• Thermal Dissipation: 48.0 BTU/hr maximum, 5.13 BTU/hr minimum
• Backplane Current: 295 mA
• Isolation Voltage: Tested to 2500 V DC for 1 second
• Compatible Wiring Arm: 1771-WH
• Fuse Rating: 12 A, 250 V rectifier fuse (1/4 x 1-1/4 inch), Bussman GBB12, IEC 127 Type F

Installation Considerations

The 1771-OAD module is compatible with 1771 I/O chassis models 1771-A1B through A4B or later, as well as 1771-AM1 and AM2 chassis. It is not compatible with 1771-A1, 1771-A2, and 1771-A4 chassis. Ensure that the total backplane current does not exceed the chassis power supply capacity to prevent overloading.

Applications

This module is suitable for controlling various AC-powered devices such as solenoids, motor starters, relays, and indicators, making it ideal for diverse industrial automation applications.

Additional Information

The 1771-OAD utilizes zero-crossing technology, allowing it to turn on when the output voltage is below a specified threshold, typically between 40 to 50 V AC. This feature reduces stress on contacts and other sensitive devices during current surges.

For proper operation with devices that include a single diode in series with the load, a shunt resistor (39 KΩ, 1 W) should be placed across the load. Note that the shunt resistor may cause the LED indicator to light when the output is off; in such cases, using an incandescent lamp instead of an LED is recommended.

By integrating the 1771-OAD module into your PLC-5 system, you can achieve efficient and reliable control over your AC-powered industrial devices.