Allen Bradley Guardmaster MSR117T Safety Relay 440R-B23211

The Allen Bradley Guardmaster MSR117T (440R-B23211) is a small, high-performance safety relay that is designed to keep an eye on emergency stops, guard doors, and safety gates in industrial automation systems. This SIL 3 and Category 4/PL e certified device runs on 24V AC/DC and has three N.O. safety outputs and one N.C. auxiliary contact. It may be controlled by one or two channels and can be reset automatically or manually.

Key Features of Allen Bradley 440R-B23211:

• Three N.O. safety outputs (4A/250V AC rated) plus one N.C. auxiliary for signaling.​

• Manual monitored or automatic reset modes for flexible safety configurations.​

• 10 million mechanical cycles and 100,000 electrical operations at full load.​

• Compliant with EN ISO 13849-1, IEC 61508, UL, CUL, CCC, and KC standards.

The MSR117T is 22.5 mm wide and fits well on DIN rails. It has cross-fault detection, infinite input simultaneity, and strong electromechanical contacts that can handle millions of cycles. The IP20/IP40-rated housing can handle tough situations up to 55°C, and the LED status indications make it easy to diagnose problems quickly.

Technical Specifications:

Usage in Industry:

This Guardmaster relay is great for single-zone safety operations like machine guarding, e-stops, and interlocks in manufacturing, maritime controls, and automation panels. Its Category 4 design and PFH of 2.451E-10 make sure that it stays up and running and follows the rules in high-risk situations.