Allen-Bradley MicroLogix 1762-OW16 16-Point AC/DC Relay Output Module

Module Overview

The 1762-OW16 is a high-density discrete output module designed for the Allen-Bradley MicroLogix 1100, 1200, and 1400 controller families. Featuring 16 independent relay contacts, this module provides the versatility to switch a wide range of AC and DC voltages, making it an essential component for controlling solenoids, motor starters, and indicator lamps. Its electromechanical relay design offers complete electrical isolation between the PLC logic and the field-side loads, ensuring robust performance in electrically noisy industrial environments.

Detailed Engineering Specifications

The 1762-OW16 is organized into two isolated groups, allowing for the control of different voltage levels within a single expansion slot.

• Module Type: Digital Relay Output (Normally Open)

• Number of Outputs: 16 Points

• Number of Groups: 2 Isolated Groups (8 points per group)

• Operating Voltage Range: 5V to 265V AC / 5V to 125V DC

• Relay Contact Ratings: 24–125V DC / 120–240V AC

• Maximum Current per Point: 2.5 Amperes

• Maximum Current per Module: 16 Amperes (total)

• Signal Delay (Typical): 10 milliseconds (On and Off)

• Backplane Current (5V DC): 120 mA

• Backplane Current (24V DC): 140 mA

• Maximum Heat Dissipation: 6.1 Watts

• Isolation Voltage: 265V (Continuous), reinforced insulation

• Hardware Termination: Removable Terminal Block (RTB)

• Operating Temperature: 0°C to 55°C (32°F to 131°F)

• Physical Weight: 0.69 lbs (0.31 kg)

Flexible Load Management

A primary advantage of the 1762-OW16 is its "dry contact" architecture. Because each of the two groups has its own common (VAC/VDC COM), you can simultaneously control a 120V AC lighting circuit on Group 0 and a 24V DC hydraulic valve on Group 1. This flexibility eliminates the need for interposing relays in many applications, simplifying cabinet wiring and reducing overall system cost.

Installation and Mechanical Reliability

The module is designed for easy DIN rail mounting and features a compact 1762-series footprint. To ensure long-term reliability of the relay contacts when switching inductive loads (such as motor starter coils or solenoids), it is highly recommended to install external surge suppression. Using a snubber circuit for AC loads or a diode for DC loads will prevent contact arcing and significantly extend the mechanical life of the 1762-OW16.

Technical FAQ

What is the minimum load requirement for these relays?

While there is no strict minimum current for operation, very low-current signals (under 10mA) may experience higher contact resistance over time due to the lack of "wetting current" needed to clean the relay contacts.

Can I replace the individual relays if one fails?

No. The relays are soldered directly to the internal PCB of the 1762-OW16. If a contact fails, the entire module or the removable terminal block must be addressed, though the terminal block itself is replaceable for quick hardware swaps.

Does this module require an external power supply?

The module draws its logic power (5V and 24V) from the MicroLogix controller’s backplane. However, the power for the actual field loads must be provided by an external source connected to the "COM" terminals of the module.