Allen-Bradley 1794-OW8XT FLEX I/O 8-Point Relay Output Module

Product Overview

The Allen-Bradley 1794-OW8XT functions as a ruggedized 8-channel relay output module within the FLEX I/O platform. This module provides isolated dry-contact outputs capable of switching both AC and DC loads up to 250V AC. The "XT" designation identifies this hardware as an extended-temperature version, specifically designed to withstand harsh industrial environments that exceed the thermal limits of standard control equipment. We supply this module in 100% Brand New condition, ensuring pristine contact surfaces and maximum mechanical life for your distributed I/O network.

Technical Specifications

• Module Type: Discrete Relay Output

• Number of Outputs: 8 Normally Open (N.O.) Relays

• Relay Contact Rating: 250V AC

• Minimum Contact Load: 100 µA @ 100 mV DC

• Initial Contact Resistance: 30 mΩ

• Bounce Time: 1.2 ms

• Switching Frequency: 1 operation every 3 seconds (max at rated load)

• Flexbus Current: 5V DC

• Power Dissipation: 5.5 Watts

• Thermal Dissipation: 18.8 BTU/hr maximum

• Weight: 0.31 lbs (0.14 kg)

Engineering Advantages

The 1794-OW8XT resolves specific field-level integration challenges through its specialized relay architecture and hardened design:

• Extreme Thermal Resilience: The XT hardware profile maintains reliable switching performance across a significantly wider temperature range than standard modules. This eliminates the need for expensive climate-control systems in remote cabinets or outdoor enclosures.

• Low-Level Signal Switching: With a minimum contact load requirement of just 100 µA at 100 mV DC, this module accurately switches low-energy signals. This capability proves vital when interfacing with high-impedance electronic inputs or sensitive instrumentation that traditional power relays cannot handle.

• Superior Load Isolation: The relay contacts provide physical separation between the backplane logic and high-voltage field wiring. This isolation protects the FLEX I/O rack from electrical noise, transients, and potential ground loops originating from heavy industrial machinery.

• Integrated Snubber Protection: The module incorporates a snubber circuit to manage off-state leakage and suppress electrical arcs during contact transition. This protection extends the mechanical life of the relay and prevents electromagnetic interference (EMI) from disrupting nearby sensitive electronics.

FAQs

• What is the difference between the 1794-OW8 and the 1794-OW8XT?

  The "XT" version features enhanced components and protective coatings that allow it to operate in extended temperature ranges. While they share the same logic and wiring footprint, the 1794-OW8XT provides superior reliability in non-climate-controlled environments.

• Does this module require a separate terminal base?

  Yes. The 1794-OW8XT must seat into a 1794 terminal base (such as the 1794-TB2, 1794-TB3, or 1794-TBN). The base handles all field wiring, allowing you to replace the module without disconnecting any wires.

• Is this a Brand New original product?

  Yes. We guarantee this unit is 100% Brand New and original. Using new relay modules is essential because relay contacts suffer from mechanical wear and oxidation over time; only a new module guarantees a full 30 mΩ initial contact resistance.

• How do I ensure the longest life for the relay contacts?

  Avoid exceeding the switching frequency of one operation every three seconds at full rated load. If your application requires high-speed cycling, consider using a solid-state output module instead to prevent mechanical fatigue.