440R-W23221

Overview of Allen Bradley 440R-W23221

The Allen Bradley 440R-W23221 is a Guardmaster MSR330P safety relay expansion module. This device is designed for the safety monitoring and control of machine systems that require redundancy and reliable safety outputs. Manufactured by Allen Bradley, it operates at 24 VDC and offers a DIN rail mount for quick installation in control panels. The 440R-W23221 model provides three normally open (3NO) safety outputs and one normally closed (1NC) auxiliary contact, allowing it to support flexible integration into a wide range of industrial safety applications. This relay helps expand the safety circuit of primary safety controllers, meeting global standards such as CE, UL, and cUL approvals. Its compact footprint and removable terminal blocks make panel layout and maintenance easier, while IP20/IP40 ratings ensure it meets typical industrial environmental demands. It is well-suited to environments where operational safety is a top priority, supporting systems designed for Performance Level e (PLe) and SIL 3 compliance.

Key Features of Allen Bradley 440R-W23221

• Designed for safety relay expansion with three NO safety outputs and one NC auxiliary contact
• Operates on 24 VDC and mounts easily to DIN rails
• Compliant with global safety standards: CE, UL, cUL
• Removable terminal blocks for simplified wiring
• IP20/IP40 enclosure ratings for standard industrial environments

Technical Specs of 440R-W23221

• Type: Guardmaster MSR330P Safety Relay Expansion Module
• Input Voltage: 24 VDC
• Contacts: 3 NO (Safety), 1 NC (Auxiliary)
• Maximum Switching Current: 2.5 A
• Mounting: DIN Rail
• Standards: CCC, CE, cUL, UL
• Performance Level: PLe per ISO13849-1, SIL 3
• Protection: IP20/IP40

Applications / Use Case

The Allen Bradley 440R-W23221 is ideal for expanding safety circuits in automated machinery and large industrial systems that require additional safety outputs. It is commonly deployed in manufacturing cells, robotic safety systems, packaging machinery, and process automation where compliance with stringent safety requirements is essential. Integrators and OEMs use this relay to increase the number of available safety contacts for emergency stops, gate switches, safety mats, or light curtains. The module’s compatibility with Allen Bradley controllers and its ability to interface with various safety devices make it a valuable addition for maintaining system uptime while maximizing operator protection. Its use improves machine safety integrity and supports flexible modifications as safety demands evolve in dynamic production settings.

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