Allen-Bradley 1790D-T0W6 6 Relay Output Base Module Overview

Product Introduction

When industrial applications require dependable relay output switching, the Allen-Bradley 1790D-T0W6 provides a compact and robust solution. This 6 relay output base module is part of the 1790D series, designed for distributed control environments. It features six Form A (normally open) single-pole, single-throw relays, each with a dedicated common point (1 point/1COM), ensuring clear channel separation for reliable signal routing. The module operates with a DeviceNet power supply voltage of 24V DC nominal (range 11…28.8V DC) and a field power supply voltage of 24V DC nominal (range 19.2…28.8V DC), making it suitable for standard industrial power systems.

Technical Specifications Breakdown

The 1790D-T0W6 delivers versatile output capabilities. Each relay can switch loads up to 2.0 A resistive across multiple voltage ranges: 5…24V DC, 30V AC, 125V AC, and 250V AC. This flexibility allows the module to control both DC and AC devices, such as solenoids, contactors, and indicator lamps. The minimum load requirement is 100 µA at 100 mV DC per input, ensuring reliable switching even for low-power signals. On-state voltage drop is a maximum of 0.5V at 2.0 A resistive load with 24V DC, minimizing power loss. Initial contact resistance is 30 MΩ, and expected contact life is 300 Kcycles resistive or 100 Kcycles inductive, providing long service in typical industrial cycles. Off-state leakage is limited to 1.5 mA max, preventing unintended activation. Output delay time is 10 ms max for both Off to On and On to Off transitions, ensuring predictable response.

Isolation between I/O and logic is provided by photocoupler isolation, with an isolation voltage of 1250V AC rms, protecting the control system from high-voltage transients. The module includes six green status indicators for quick visual diagnostics. Wiring uses a terminal block with M3.0 screws, and the recommended screw torque is 7 lb-in max (use copper or copper-clad aluminum conductors).

Industry Applications

The 1790D-T0W6 is well-suited for discrete manufacturing, packaging machinery, and material handling systems. For example, in a conveyor system, the relay outputs can control motor starters and solenoid valves, with each output independently switching up to 2.0 A at 24V DC. In a packaging line, the module can actuate pneumatic cylinders and indicator lights, leveraging the 125V AC capability for direct control of AC-powered devices. Compared to solid-state output modules, relay outputs offer galvanic isolation and higher inrush current handling, making them ideal for inductive loads like relays and contactors.

Installation & Setup Guidance

Mount the 1790D-T0W6 on a DIN rail in a clean, dry environment within the specified voltage ranges. Connect the DeviceNet power supply (24V DC, 11…28.8V DC) and field power supply (24V DC, 19.2…28.8V DC) separately. Use copper or copper-clad aluminum conductors with a maximum screw torque of 7 lb-in. Wire each relay output to its load, ensuring the common terminal (1 point/1COM) is correctly connected. Verify polarity for DC loads and observe proper fusing per local codes. After wiring, power up and check the green status indicators for each channel.

Maintenance & Reliability

Periodically inspect the terminal block connections for tightness and check for signs of overheating or contact wear. The expected contact life of 300 Kcycles resistive and 100 Kcycles inductive provides a maintenance baseline; replace the module if relay failure is detected. Keep the module free from dust and moisture to ensure reliable photocoupler isolation. Follow the manufacturer's guidelines for routine inspection intervals.

Compatibility & Integration

The 1790D-T0W6 integrates with Allen-Bradley DeviceNet networks, allowing seamless communication with controllers like CompactLogix and ControlLogix. It can also be used in standalone applications with a DeviceNet scanner. The module's 1 point/1COM configuration simplifies wiring and troubleshooting in multi-device setups.

Selection Guide & Purchasing Advice

Before purchasing the 1790D-T0W6, verify your system's power supply voltage and load requirements match the module's specifications. Ensure the DeviceNet network is properly configured. For current availability and lifecycle status, contact BluePLC Industrial. As a trusted supplier, BluePLC Industrial offers genuine Allen-Bradley modules and expert support for your automation needs.