Allen-Bradley 440R-W23221 Guardmaster MSR330P Modular Safety Relay

Product Overview

The Allen-Bradley 440R-W23221 belongs to the Guardmaster MSR330P family, functioning as a high-performance modular monitoring safety relay. This unit specifically serves as a Group 1 output expansion module within a modular safety system. It provides essential logic-controlled switching for machine guarding applications, ensuring safe shutdown procedures when the system detects a fault or emergency stop request. We supply this module as 100% Brand New and original, providing a critical replacement path for systems utilizing this discontinued modular architecture.

Technical Specifications

The 440R-W23221 utilizes a compact housing to deliver reliable safety switching capacity:

Engineering Advantages

The 440R-W23221 solves specific integration challenges in complex safety circuits:

• Modular Scalability: This relay functions within a modular "plug-and-play" architecture. You expand your safety output capacity by simply adding this Group 1 module to the MSR330 system, eliminating the need for extensive rewiring of the base controller.

• Space-Efficient Design: The ultra-slim profile (weighing only 0.42 lbs) allows for high-density mounting on standard DIN rails. This solves the problem of "cabinet bloat" in facilities with limited enclosure space.

• Low Thermal Footprint: Drawing only 1.5 Watts, the module generates minimal heat. This permits side-by-side mounting without the risk of thermal derating or the need for specialized cooling fans in the control cabinet.

• Auxiliary Feedback: The inclusion of a 1NC auxiliary contact allows the PLC or monitoring system to verify the relay's mechanical state. This diagnostic loop prevents the machine from restarting if the safety contacts fail to cycle correctly.

FAQs

Can I use the 440R-W23221 as a standalone safety relay?

No. The 440R-W23221 is a modular output expansion (Group 1). It requires an MSR330 series base module to provide the necessary logic and input monitoring. It does not possess its own safety inputs.

What is the primary benefit of the MSR330P modular system?

The MSR330P system separates the input monitoring logic from the output switching. This modularity allows you to replace a damaged output module like the 440R-W23221 without replacing the more expensive base logic unit, significantly reducing maintenance costs.

Is this a "New-Old-Stock" (NOS) item?

Yes. Since the manufacturer has discontinued this series, we source these units from factory-sealed surplus inventory. We guarantee the unit is 100% Brand New, unused, and remains in its original Allen-Bradley packaging to ensure maximum reliability for your safety-critical system.

How do I install the module on the DIN rail?

The module features a standard 35mm DIN rail clip. Snap the unit onto the rail and ensure it makes proper contact with the modular bus connectors of the adjacent MSR330 base module to establish logic communication and power.