When a Panel Runs Out of Outputs
A system integrator recently faced a familiar problem: a MicroLogix-controlled packaging line needed 32 discrete outputs, but the existing rack had no spare slots. Adding a second controller was too costly. The solution was the Allen-Bradley 1762-OB32T, a high-density solid-state output module that packs 32 channels into a single MicroLogix slot.
What Is the 1762-OB32T?
The 1762-OB32T is a MicroLogix-compatible solid-state output module from Allen-Bradley. It provides Thirty-Two (32) source-type outputs arranged in Two (2) isolated groups of Sixteen (16) channels each. The module delivers a nominal output voltage of 24VDC with an output voltage range of 10.2-26.4 VDC. It suits loads such as indicating lights, sounding devices, solenoid-actuated devices, and small DC motors.
Technical Specifications That Matter
Output Capacity
Each channel handles 0.5 A at 60 °C (140 °F). Each group supports 2.0 A, and the full module supports 4.0 A at the same temperature. These three limits are different, so plan loads carefully. The minimum on-state current is 1 mA.
Isolation and Protection
The module carries an isolation rating of 1200V AC for 2 s or 1697V DC for 2 s, with 75V DC working voltage based on IEC Class 2 reinforced insulation. The two isolated output groups let you separate circuits electrically.
Switching Behavior
Signal delay is 0.5 ms turn-on and 4.0 ms turn-off for resistive loads. Maximum off-state leakage current is 0.1 mA at 26.4V DC. Surge current reaches 2.0 A, repeatable every 2 s at 60 °C (140 °F) for 10 ms.
Physical and Environmental Data
Heat dissipation is 3.4 Watts. Wire size is 22, 24, and 26 AWG. The module operates in a Pollution Degree 2 environment at altitudes up to 6562 feet without derating.
Where the 1762-OB32T Fits
Packaging and Material Handling
A single module can drive 32 solenoid valves or indicator lamps. The 0.5 A per channel covers many small DC loads directly.
Panel Retrofit Projects
When a panel runs out of slots, this module adds 32 outputs without a second rack. The 4.0 A module limit keeps total load planning straightforward.
Replacement and Upgrade Scenarios
If an existing 1762-OB32T fails, a drop-in replacement restores output capacity quickly. SpareTechPLC supplies this module for maintenance and upgrade programs. Please verify current lifecycle status and availability with SpareTechPLC before ordering.
Installation and Setup
Mount the module in an enclosure designed to prevent injury. The enclosure must have flame-retardant properties with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-metallic. The interior must be accessible only by a tool. Use 22, 24, or 26 AWG wire. This is a source output module, so confirm your wiring method matches source configuration. Keep loads within the per-channel, per-group, and per-module current limits.
Maintenance and Reliability
Solid-state outputs have no moving contacts, so wear is minimal. Inspect terminal connections periodically for tightness and heat discoloration. Verify that ambient temperature stays at or below 60 °C (140 °F) to preserve current ratings. Keep the enclosure free of conductive dust and moisture. For safety-related maintenance, follow the manufacturer’s safety manual and inspect periodically.
Compatibility and Integration
The 1762-OB32T works with MicroLogix controllers. It communicates through the host controller’s I/O bus, not a separate network protocol. Confirm your controller model and rack configuration accept this module before purchase.
Selection Guide
Before buying, verify your required channel count, source wiring compatibility, and total current demand. Check that your controller supports the 1762 series. SpareTechPLC is a reliable supplier of industrial automation parts and can help confirm fit. Contact SpareTechPLC for current stock and replacement options.
Frequently Asked Questions
How many outputs does the 1762-OB32T provide?
It provides Thirty-Two (32) outputs in Two (2) isolated groups of Sixteen (16) channels each.
What is the output voltage range?
The output voltage range is 10.2-26.4 VDC with a nominal output of 24VDC.
Can I use it for AC loads?
The module is a source DC output module. AC loads require interposing circuitry between the module and the load.
What is the maximum current per module?
The maximum continuous output current per module is 4.0 A at 60 °C (140 °F).
What wire sizes does it accept?
It accepts 22, 24, and 26 AWG wire.
