Product Overview

The 1790-T0W8X is an 8 Relay Output Expansion Module from Allen-Bradley, designed to extend the output capabilities of compatible control systems. This module features Form A, normally open relay outputs with single pole, single throw configuration, making it a reliable choice for switching various loads in industrial environments. Its compact design and robust specifications ensure seamless integration into existing automation setups.

Technical Specifications Analysis

The 1790-T0W8X offers a versatile output voltage range that is load dependent: 5…28V dc @ 2.0 A resistive, 48V ac @ 0.8 A resistive, 125V ac @ 2.0 A resistive, and 250V ac @ 2.0 A resistive. It requires a minimum load of 100 µA and 100mV dc per input. The on-state voltage drop is a maximum of 0.5V @ 2.0 A with a resistive load at 24V dc. Initial contact resistance is 30 mΩ, and expected contact life is 300 Kcycles resistive and 100 Kcycles inductive. Off-state leakage is a maximum of 1.5 mA. Output delay time is 10 ms max for both Off to On and On to Off transitions. The module includes 8 green status indicators and uses a 1 point/1COM common type. Field power supply voltage is 24V dc nominal with a voltage range of 19.2…28.8V dc. Power dissipation is 2.3W @ 28.8V dc per channel. Isolation between I/O and logic is provided via photocoupler with an isolation voltage of 1250V ac rms. Wiring uses a terminal block (M3.0) with a screw torque of 7 lb-in max, requiring copper or copper-clad aluminum conductors. The module weighs 0.38 lbs (0.17 kg).

Application Scenarios & Usage Methods

The 1790-T0W8X is ideal for controlling discrete loads such as solenoids, relays, and indicator lights in manufacturing lines. For example, in a packaging machine, it can switch 24V dc actuators at 2.0 A resistive load. In a conveyor system, it can handle 125V ac motors at 2.0 A. When used with 250V ac loads, ensure the total current stays within the 2.0 A resistive limit. The module's fast 10 ms response time supports precise timing in automated sequences.

Installation Guide & Packing List

Mount the module on a DIN rail or panel using the provided slots. Connect field power (19.2…28.8V dc) to the designated terminals, observing polarity. Wire output loads to the terminal block using copper conductors, tightening screws to 7 lb-in max. Typical package includes the 1790-T0W8X module, terminal block, and mounting hardware. Always refer to the user manual for detailed wiring diagrams.

Purchasing Advice

When selecting the 1790-T0W8X, verify that your system's field power supply matches the 24V dc nominal with a range of 19.2…28.8V dc. Ensure your load requirements fall within the specified voltage and current limits. For reliable sourcing, PetroPartsOnline offers genuine Allen-Bradley modules with fast shipping and competitive pricing.

Repair & Maintenance Tips

Periodically inspect the terminal block for tight connections and signs of corrosion. Clean the module with a dry cloth to prevent dust buildup. Store in a dry, static-free environment. Avoid exceeding the rated contact life of 300 Kcycles resistive or 100 Kcycles inductive to maintain performance.

Frequently Asked Questions (FAQs)

Q: What is the output voltage range of the 1790-T0W8X?

A: The output voltage range is load dependent: 5…28V dc @ 2.0 A resistive, 48V ac @ 0.8 A resistive, 125V ac @ 2.0 A resistive, and 250V ac @ 2.0 A resistive.

Q: What is the field power supply requirement for this module?

A: The field power supply is 24V dc nominal with a voltage range of 19.2…28.8V dc.

Q: How many outputs does the 1790-T0W8X have?

A: It has 8 relay outputs, each Form A normally open, single pole, single throw.

Q: What is the expected contact life of the relays?

A: Expected contact life is 300 Kcycles resistive and 100 Kcycles inductive.

Q: What type of isolation does the module use?

A: It uses photocoupler isolation between I/O and logic with an isolation voltage of 1250V ac rms.