Allen-Bradley 1762-OB8 Output Module Specs

Product Introduction

The 1762-OB8 module from Allen‑Bradley expands your MicroLogix 1200 system with eight digital DC output channels. Each channel sources 24V DC at 0.5A, with a total aggregate current of 4A per module. Its solid‑state design ensures fast response – 0.1 ms turn‑on and 1.0 ms turn‑off under resistive loads. This 1762-OB8 operates over a wide temperature range (0 to 55 °C) and fits standard DIN rails, making it ideal for conveyor controls, packaging machines, and simple actuator interfaces. With isolated outputs (tested at 1200V AC) and low power dissipation of just 1.6W, the 1762-OB8 delivers both safety and efficiency in compact spaces.

Technical Specifications – Core Parameters

Let’s begin with the electrical characteristics. The 1762-OB8 accepts an operating voltage between 20.4 and 26.4V DC, matching standard 24V industrial supplies. For each of its 8 output points, the maximum current load is 0.5A, while the entire module can handle up to 4A continuously. Additionally, it supports a 2A intermittent surge for 10 ms, repeating every 2 seconds – useful for momentary inrush loads like small solenoids or indicator lamps.

Regarding signal timing, this 1762-OB8 offers a maximum ON‑state delay of 0.1 ms and an OFF‑state delay of 1.0 ms at resistive loads. Its ON‑state voltage drop is only 1.0V DC maximum, which minimizes power loss. The OFF‑state leakage current stays below 1.0 mA, preventing false triggering on sensitive inputs. Furthermore, the backplane current consumption is just 115 mA at 5V DC, so it places minimal burden on the controller’s power budget.

Isolation and protection are equally robust. The 1762-OB8 provides group‑to‑backplane isolation tested at 1200V AC (or 1697V DC) for one second, ensuring reliable separation between field wiring and the logic side. This feature is critical for preventing ground loops and protecting the CPU from transient surges.

Mechanical and Environmental Ratings

Now consider the physical and environmental limits. The 1762-OB8 operates within a temperature range of 0 to 55 °C (32 to 131 °F) and can be stored from –40 to 85 °C (–40 to 185 °F). Relative humidity may range from 5% to 95% non‑condensing, covering most factory floor conditions. Moreover, it withstands 30G shock and 5G vibration at 500 Hz, making it suitable for machinery with moderate motion.

In terms of mounting, this module clips directly onto a standard DIN rail, simplifying installation and removal. Its compact dimensions – 90 x 87 x 40.4 mm – allow dense packing in control cabinets. Power dissipation is rated at 1.6W, which helps keep panel temperatures low. For altitude, the 1762-OB8 is certified for operation up to 6561 feet (2000 meters) above sea level.

Installation Guidelines for the 1762-OB8

Installing the 1762-OB8 is straightforward, but following correct steps ensures long‑term reliability. First, ensure the controller is powered off before handling any expansion I/O. Next, align the module with the DIN rail and snap it into place until the locking mechanism clicks. Then, connect the removable terminal block – use copper wire rated for 24V DC, and tighten screws to 0.56 N·m (5 lb‑in) to avoid loose connections.

After mounting, assign the output addresses within your MicroLogix 1200 program. The 1762-OB8 automatically maps to the next available output words, so verify the I/O configuration in RSLogix 500 or Connected Components Workbench. Finally, power up the system and test each point with a multimeter to confirm correct sourcing behavior – remember that this module sources current to the load, so the common terminal must be connected to DC return.

For maximum power supply distance, do not exceed 6 module lengths between the 1762-OB8 and the power supply. This limitation prevents voltage drop along the backplane, ensuring stable operation. Additionally, maintain proper clearance around the module for airflow, especially in high‑temperature environments.

Common Applications and Use Cases

The 1762-OB8 excels in controlling DC‑powered devices such as pilot lights, relays, small valves, and buzzer indicators. For instance, in a packaging line, it can trigger solenoid actuators for diverting products. Specifically, its fast switching speed suits applications requiring precise timing, like pick‑and‑place stations. Moreover, the surge capability handles momentary current peaks without tripping, so you can drive incandescent lamps or capacitive loads with confidence.

Because the 1762-OB8 is a sourcing output module, it works best with loads that have one side connected to DC common. This is typical in many North American and Asian machine designs. If your system requires sinking outputs, consider other models in the MicroLogix 1200 family. However, for most small‑to‑medium automation tasks, this 1762-OB8 provides a cost‑effective and dependable solution.

Certifications and Compliance

While we do not include certificates in the package, the 1762-OB8 carries UL, c‑UL, and CE marks. These certifications confirm compliance with North American and European safety and electromagnetic compatibility standards. Therefore, you can integrate this module into machines destined for global markets without additional regulatory hurdles.

Packaging List

When you receive the 1762-OB8, the box contains the following items:

• 1 x 1762-OB8 Digital DC Output Module

• 1 x Removable Terminal Block (18‑pin)

• 1 x DIN rail mounting clip (pre‑attached)

• 1 x Quick Start Guide (printed)

Please note that cables, programming software, and mounting hardware are not included. Also, no certificates or warranty documents are shipped with this product – those are managed through your Rockwell Automation distributor.

Shipping and Delivery

We ship all orders via FedEx, UPS, or DHL depending on your location and service preference. Each parcel is securely packed with anti‑static protection to safeguard the 1762-OB8 during transit. Tracking numbers are provided within 24 hours of dispatch, and express delivery typically takes 3‑7 business days worldwide.

Frequently Asked Questions (FAQ)

Q1: Can the 1762-OB8 drive a 24V DC motor directly?
A: It can handle small motors with a running current under 0.5A, but check the start‑up surge. If the motor draws more than 2A peak, use an interposing relay to protect the module.

Q2: How do I know if my 1762-OB8 is working correctly?
A: Monitor the LED indicators on the front panel – each output has a green status light. Additionally, use a voltmeter across the output and common terminals to verify the presence of 24V when the output is energized.

Q3: Is the 1762-OB8 compatible with the MicroLogix 1100 controller?
A: Yes, the MicroLogix 1100 supports expansion I/O modules like the 1762-OB8, provided you use the proper bus connector and stay within the total current budget of the power supply.

Q4: What wire gauge should I use for connecting loads?
A: Use 14‑22 AWG copper wire rated for 75°C. For currents near 0.5A, 18 AWG is recommended to minimize voltage drop over long distances.

Q5: Can I replace a faulty output point on the 1762-OB8?
A: No, output points are not individually replaceable. If one channel fails, replace the entire module. However, the solid‑state design offers high reliability under normal operating conditions.