Product Overview

The Allen-Bradley 1762-OW16 is a high-density relay output expansion module, purpose-built for the MicroLogix 1100, 1200, and 1400 programmable logic controller (PLC) families. As a vital component of the 1762 MicroLogix Expansion I/O series, this module offers 16 discrete output points, providing engineers with the flexibility to interface control logic with a wide array of field-level electrical loads. By utilizing mechanical relay outputs, the 1762-OW16 ensures complete galvanic isolation between the controller’s logic circuitry and high-voltage field devices, which is essential for protecting the integrity of the control system in harsh industrial environments.

This module is designed for versatility, supporting both AC and DC switching voltages across a range of 5V to 265V AC or 5V to 125V DC. With two isolated groups of eight outputs each, it allows for the simultaneous management of disparate voltage domains on a single module—a common requirement in complex machine control applications. Whether you are driving contactors, solenoid valves, pilot indicators, or intermediate relays, the 1762-OW16 delivers reliable performance and robust signal switching. Its compact design and DIN-rail or panel-mount capability make it an optimal choice for space-constrained industrial cabinets where reliability and long-term durability are not optional.

Technical Specifications

Model Configuration Explanation

The 1762-OW16 catalog number follows a standardized Rockwell Automation logic:

• 1762: Represents the MicroLogix expansion I/O platform, ensuring compatibility with the 1100/1200/1400 controller backplane.

• O: Signifies an Output module.

• W: Designates the use of mechanical Relay contact outputs, preferred for high-voltage and load-versatile applications.

• 16: Indicates the module provides 16 discrete output channels.

Typical Applications

The 1762-OW16 is utilized across diverse industrial automation sectors:

• Motor Control Centers (MCC): Interfacing PLC logic with contactor coils to trigger motor starters and drives.

• Process Valve Control: Switching solenoid-operated pneumatic and hydraulic valves in batch process systems.

• Lighting & Climate Control: Managing high-current lighting contactors and environmental control actuators in large-scale building automation.

• Packaging and Bottling: Driving high-speed indicators and intermediate relays for carton assembly and labeling lines.

• Remote Pump Stations: Providing isolated switching for secondary chemical dosing pumps and level-monitoring relay circuits.

System Compatibility

The 1762-OW16 is optimized for integration with the MicroLogix 1100, 1200, and 1400 platforms. It communicates directly with the controller through the 1762 bus, which provides both the internal logic power and data exchange paths. For optimal system configuration, maintain the correct distance from the CPU backplane as specified in your controller's manual. Its ruggedized design ensures that it performs consistently when used in tandem with other 1762 analog or digital I/O expansion modules, provided the total system power budget is monitored.

Deployment Guidelines

• Environmental Seating: Install the module in an environment conforming to IP20 ratings, housed within an industrial enclosure. Ensure the mounting surface is level and securely grounded.

• Mounting Protocol: The module supports snap-on mounting for 35mm DIN rails or direct panel mounting. Use the provided mounting tabs to secure the unit against vibration.

• Terminal Wiring: Each relay output is designed for normally open (NO) operation. Ensure that field wiring is rated for the maximum expected current (2.5 A per point) and adheres to proper insulation standards for AC/DC environments.

• Inductive Load Suppression: When switching inductive loads (such as motor starters or solenoids), always install an external suppression device (e.g., an MOV, RC circuit, or diode) across the load to prevent relay contact degradation due to arc-back.

Product Advantages

• High Output Density: With 16 relay points in a single compact module, this unit optimizes cabinet space and reduces the number of expansion modules required.

• Isolation Flexibility: Two separate groups of 8 outputs allow for independent voltage isolation, permitting the control of different machine sections with varying power requirements from one module.

• Robust Switching: Mechanical relay outputs are inherently resistant to electrical noise and transient spikes, making them a safer choice than transistor outputs for high-voltage field loads.

• Standardized Footprint: Its compatibility with the broad MicroLogix 1762 family ensures it is a drop-in component for most maintenance and upgrade scenarios.

Ordering Information

• 1762-OW16 Relay Output Module.

• Ships with standard Rockwell Automation documentation.

• Note: Field wiring terminal blocks are typically included. If replacement is needed, ensure the part matches the 1762-series terminal block specifications.

Frequently Asked Questions

• Can I switch both 24V DC and 120V AC on the same 1762-OW16?

  Yes. Because the 16 outputs are divided into two isolated groups of 8, you can supply 24V DC power to one group and 120V AC to the other, maintaining proper isolation.

• What is the response time for these relay outputs?

  The mechanical relay contacts have a signal delay of approximately 10 ms. While this is sufficient for most control applications, it should not be used for high-speed pulse applications.

• Is the 1762-OW16 hot-swappable?

  No. The MicroLogix 1762 expansion I/O system does not support hot-swapping. Always disconnect power from the controller and the field loads before installing or removing modules.

• How do I protect the relay contacts from sticking?

  Always use surge suppression devices on inductive loads. Excessive current or switching highly inductive loads without suppression is the most common cause of contact welding.

• Can I use this with an analog output?

  No. This module is exclusively designed for discrete, digital ON/OFF switching. It cannot produce a variable analog signal.

• What is the maximum current allowed per output point?

  Each output channel is rated for a maximum current of 2.5 A. Always ensure your external load does not exceed this rating, or you risk damaging the internal relay.

• Are the relay outputs Normally Open or Normally Closed?

  The 1762-OW16 utilizes Normally Open (NO) relay contacts. The circuit is completed only when the PLC energizes the specific relay output.

• Is a separate power supply required for the module?

  The module receives its communication power from the MicroLogix backplane. You must, however, provide external field power to the relay terminals to drive your field loads.

• How can I tell if a relay has failed?

  If an output LED indicator is ON but the device it controls does not respond, or if an output remains stuck ON even when the PLC logic is OFF, the relay contact is likely welded.

• Does the module require configuration in the PLC software?

  Yes. In RSLogix 500 or Studio 5000, you must add the module to the I/O configuration tree to ensure the CPU recognizes the added points and maps them to the memory table correctly.