1791-16AC | Allen-Bradley Block I/O Module - Petro Auto Tech

Product Overview

The 1791-16AC is a Block I/O module manufactured by Allen-Bradley. This module integrates a power supply, PLC interface, I/O connections, and signal processing circuitry into a single unit. It is designed for implementing Remote I/O architecture in industrial automation systems. With 16 input channels and 16 output channels, it provides a compact and efficient solution for distributed control.

Technical Specifications Analysis

The 1791-16AC operates on a nominal input voltage of 120VAC. It has an on-state voltage range of 79 to 132 Volts AC at 47-63 Hz. The module features sixteen discrete input channels with an on-state current of 12.3 mA at 132 Volts maximum. The off-state voltage is 35 Volts maximum, and the off-state current is 2.3 mA minimum. For outputs, the module provides sixteen 120VAC outputs arranged in 2 groups of 8. The output voltage range is 20-132VAC. External power requirements are 85 to 132 Volts AC at 150 mA. The module dissipates a maximum of 31.3 Watts of power and 106.73 BTU/Hr of thermal energy. It weighs 2.00 lbs (0.91 kg) and supports both vertical and horizontal mounting.

Application Scenarios & Usage Methods

This module is ideal for remote I/O applications where you need to collect discrete signals from field devices and control outputs over a distance. For example, in a manufacturing plant, you can use the 1791-16AC to monitor limit switches and proximity sensors on a conveyor line. The 16 input channels connect to these binary devices, while the 16 outputs control pilot lamps and relay coils. The module communicates with the main PLC via a Remote I/O adapter, using a daisy-chain topology for easy expansion. Another scenario is in material handling systems, where the module manages solenoid valves and horn alerts based on input from pushbutton switches and float switches.

Installation Guide & Packing List

Mount the 1791-16AC in either a vertical or horizontal orientation. Ensure proper air circulation for cooling, as output current ratings vary by mounting position. For vertical mounting, the output current rating is 300 mA at 60 degrees Celsius and 600 mA at 30 degrees Celsius. For horizontal mounting, it is 150 mA at 60 degrees Celsius and 300 mA at 30 degrees Celsius. Connect external power within 85 to 132 Volts AC. Use the integrated Remote I/O interface to link to the scanner. The packing list typically includes the 1791-16AC module and documentation. Always verify the continuous current requirements of connected devices.

Purchasing Advice

When selecting the 1791-16AC, confirm that your system requires 16 inputs and 16 outputs at 120VAC. Check the external power supply range of 85-132VAC to ensure compatibility. For reliable supply, consider purchasing from Petro Auto Tech, an industrial automation parts supplier. This module supports both vertical and horizontal mounting, so plan your cabinet layout accordingly. The maximum power dissipation of 31.3 Watts helps in sizing your enclosure cooling.

Repair & Maintenance Tips

Regularly inspect the 1791-16AC for dust accumulation and ensure ventilation openings are clear. Check all wiring connections for tightness and signs of corrosion. Store the module in a dry, static-free environment when not in use. Avoid exposing the module to excessive vibration or moisture. Periodically verify that the input and output signals match expected states using a multimeter.

Frequently Asked Questions (FAQs)

Q: What is the input voltage range for the 1791-16AC?

A: The nominal input voltage is 120VAC, with an on-state voltage range of 79 to 132 Volts AC at 47-63 Hz.

Q: How many outputs does this module have?

A: The 1791-16AC has sixteen 120VAC outputs arranged in 2 groups of 8.

Q: Can I mount this module vertically?

A: Yes, the 1791-16AC supports both vertical and horizontal mounting. Output current ratings vary by orientation.

Q: What is the maximum power dissipation?

A: The maximum power dissipation is 31.3 Watts, with a thermal dissipation of 106.73 BTU/Hr.

Q: What external power is required?

A: The module requires an external power supply of 85 to 132 Volts AC at 150 mA.