Allen-Bradley 1790-T0A8X I/O Module 0.5A

Allen-Bradley 1790-T0A8X 8 Output Base Module

Product Introduction

The Allen-Bradley 1790-T0A8X brings eight nonisolated AC outputs to your control system. This base module operates directly with 120V AC field power. You can connect Pin 1 for V AC and Pin 2 for COM without extra wiring since all V AC terminals share an internal connection. Similarly, all COM terminals are also internally connected. Therefore, installation becomes much faster and cleaner. The module supports a wide load voltage range from 15V to 132V RMS. Each output handles up to 0.5A RMS continuously. The 1790-T0A8X also provides a low on-state voltage drop of just 1.3V RMS at full load. Its operate time reaches only 1ms maximum, while release time stays within half a cycle plus 1ms. For applications requiring high reliability, this module delivers consistent performance.

Technical Specifications of the 1790-T0A8X

Output Characteristics

• Number of outputs: 8 points, nonisolated.

• Load voltage range: 15…132V RMS.

• Maximum load current: 0.5A RMS per point.

• Minimum load current: 10 mA RMS.

• Off-state leakage current: 1.0 mA RMS maximum at 100V RMS, 60 Hz.

• On-state voltage drop: 1.3V RMS maximum at rated load.

• Operate time: 1 ms maximum.

• Release time: 1/2 cycle + 1 ms maximum.

• Common type: 8 points share 8 COM terminals.

Power and Isolation

• External AC supply: 110V RMS, 60 Hz.

• Voltage range: 15…132V RMS, 60 Hz.

• Power dissipation: 5.2W at rated current.

• Isolation (I/O to logic): Photocoupler isolation.

• Isolation voltage: 1250V AC RMS.

• Field power: Non-isolated internally.

• Insulation resistance: Min 1,000 MΩ (input-output).

• Dielectric strength: 2500V RMS for 1 minute (input-output).

Indicators and Wiring

• Indicators: 8 green status LEDs, one per output.

• Terminal block: M3.0 screws.

• Torque: 7 lb-in maximum.

• Conductor material: Copper or copper-clad aluminum.

Mechanical and Environmental Data

This module weighs exactly 1.36 kg (3.00 lbs). Its rugged housing protects internal circuits from dust and light impacts. The operating temperature range suits typical industrial environments from 0°C to 55°C. Storage temperature extends from -40°C to 85°C. Relative humidity can reach 5% to 95% non-condensing. Additionally, the 1790-T0A8X meets standard industrial vibration and shock requirements. You can mount it directly on a DIN rail or panel. Always keep the module away from high-voltage cables and heat sources.

Installation Guidelines for the 1790-T0A8X

First, ensure field power is completely turned off before wiring. Connect the 120V AC live wire to Pin 1 (V AC). Then connect the neutral wire to Pin 2 (COM). Because all V AC terminals are internally connected, you only need one power supply feed for all eight outputs. Similarly, the internal COM connection simplifies return wiring. Use copper conductors with an appropriate gauge for 0.5A per point. Tighten each screw to exactly 7 lb-in. Over-tightening may damage the terminal block. Next, mount the 1790-T0A8X securely onto a DIN rail. Push the module until the locking clip clicks. After wiring, apply power and check the eight green LEDs. Each LED lights up when its corresponding output is active. Furthermore, verify that the load voltage stays within 15-132V RMS. Lower voltages may not guarantee proper operation due to the 10mA minimum load current.

Packaging List for the 1790-T0A8X

• One Allen-Bradley 1790-T0A8X Base Module (8 outputs)

• One product label sheet

• One quick start guide (printed)

• No mounting screws included (use standard M3 hardware)

• No communication cables included

Note: This package does not include certificates or warranty statements. Shipping documents are separate.

Shipping Information

All orders ship via FedEx, UPS, or DHL depending on your region. Delivery typically takes 3-7 business days for major industrial zones. Tracking numbers are provided within 24 hours after dispatch.

Frequently Asked Questions (FAQ)

1. Can I mix AC and DC loads on the same 1790-T0A8X module?
No, this module is designed exclusively for AC loads from 15V to 132V RMS. Do not connect DC loads because the internal circuitry and leakage current ratings apply only to AC.

2. What happens if my load draws less than 10 mA RMS?
The module may not turn off correctly. The minimum load current is 10 mA RMS. Below this value, the off-state leakage current (1.0 mA) could keep sensitive loads partially energized.

3. Is the 1790-T0A8X isolated from the logic side?
Yes, it uses photocoupler isolation between I/O and logic with a rating of 1250V AC RMS. However, field power terminals (V AC and COM) are non-isolated from each other.

4. Can I use this module with 230V AC systems?
No, the maximum voltage rating is 132V RMS. For 230V AC applications, please select another Allen-Bradley module with a higher voltage range.

5. How many 1790-T0A8X modules can I connect to one controller?
The total number depends on your controller’s backplane current and network limitations. Generally, you can expand up to 8 modules per system, but refer to your specific controller manual for exact limits.