Allen-Bradley 1790-T0A8X 120V AC 8-Output Base Module Overview

Introduction

When an industrial process demands reliable switching of multiple 120V AC loads from a single compact module, the Allen-Bradley 1790-T0A8X delivers a straightforward solution. This base module provides eight nonisolated outputs, each capable of handling up to 0.5 A rms, making it a practical choice for controlling solenoids, relays, and indicator lamps in automated machinery. Designed for simplicity and durability, the 1790-T0A8X integrates easily into existing control panels.

Technical Specifications

The 1790-T0A8X operates with a load voltage range of 15…132V rms, accommodating common AC line voltages. Each output supports a maximum load current of 0.5 A rms and a minimum load current of 10 mA rms. Off-state leakage current is limited to 1.0 mA rms at 100V rms, 60 Hz, while the on-state voltage drop stays under 1.3V rms at full load. Operate time is 1 ms maximum, and release time is 1/2 cycle plus 1 ms maximum. Insulation resistance between input and output is at least 1,000 MΩ, with a dielectric strength of 2500V rms for one minute. The module uses photocoupler isolation between I/O and logic, rated at 1250V ac rms. Field power is non-isolated. Eight green status indicators provide clear visual feedback for each output.

Industry Applications

In a typical manufacturing line, the 1790-T0A8X can control a bank of 120V AC pilot lights or small solenoid valves, consolidating eight discrete outputs into one module. This reduces wiring complexity and panel space. For packaging machinery, the module's fast 1 ms operate time ensures precise timing for actuation sequences. The nonisolated output design is well-suited for applications where all loads share a common AC supply, simplifying installation and reducing component count.

Installation & Setup

To install the 1790-T0A8X, connect 120V AC field power to the V ac terminal (pin 1) and COM (pin 2). All V ac terminals are internally connected, as are all COM terminals. Use copper or copper-clad aluminum conductors with a maximum screw torque of 7 lb-in for the M3.0 terminal block. The module requires an external AC power supply of 110V rms, 60 Hz, with a voltage range of 15…132V rms, 60 Hz. Power dissipation is 5.2 W at rated current. Ensure proper isolation between I/O and logic circuits as specified.

Maintenance & Reliability

Routine inspection of the 1790-T0A8X should focus on verifying secure terminal connections and checking that the green status indicators illuminate correctly for each active output. The photocoupler isolation provides reliable electrical separation between the control logic and field wiring, reducing the risk of ground loops. Given the module's solid-state design, there are no moving parts to wear, contributing to long service life in continuous-duty applications. Keep the enclosure free of dust and moisture to maintain optimal performance.

Selection Guide & Purchasing Advice

Before ordering the 1790-T0A8X, verify your system's AC supply voltage (15…132V rms, 60 Hz) and ensure the total load current per output does not exceed 0.5 A rms. Confirm that your application can tolerate nonisolated outputs and that the common wiring scheme (8 points per 8 COM) aligns with your load distribution. For complete technical specifications or to check current availability, contact BluePLC Industrial. Our team can assist with compatibility questions and provide prompt delivery for your automation needs.