440R-N23126 | Allen-Bradley | Guardmaster MSR127T Safety Monitoring Relay

Product Description

The 440R-N23126 is a versatile, high-reliability safety monitoring relay within the Allen-Bradley Guardmaster MSR127T family. This unit is specifically engineered to provide a robust interface between safety input devices—such as E-stops, light curtains, or safety gates—and the machine's final control elements. It ensures that any detected fault or safety breach results in an immediate and controlled cessation of hazardous motion.

The MSR127T (440R-N23126) features triple safety output contacts and a dedicated auxiliary contact for status feedback. It supports both single and dual-channel wiring configurations, offering automatic or manual reset options to suit various operational safety requirements. Its compact 22.5 mm housing is designed for space-efficient DIN rail mounting in industrial control cabinets.

Detailed Technical Specifications

• Model Number: 440R-N23126

• Brand: Allen-Bradley

• Product Line: MSR127T (Automatic/Manual Reset)

• Input Voltage: 24V AC/DC

• Safety Outputs: 3 Normally Open (N.O.)

• Auxiliary Outputs: 1 Normally Closed (N.C.)

• Input Configuration: 1 N.C., 2 N.C., or Light Curtain (OSSD)

• Reset Type: Monitored Manual or Automatic/Manual (T-Type)

• Housing Width: 22.5 mm

• Mounting: 35 mm DIN Rail

• Terminal Type: Removable Screw Terminals

• Safety Category: Cat 4 per EN 954-1; SIL CL3 per EN 62061; PLe per ISO 13849-1

• Operating Temperature: -5 to 55 degrees Celsius (23 to 131 degrees Fahrenheit)

• Enclosure Rating: IP40 (Terminal IP20)

• Net Weight: 0.26 kg (0.57 lbs)

Industrial Application Scenarios

The 440R-N23126 is widely utilized in high-risk manufacturing sectors, including automotive robotic cells, high-speed packaging machinery, and material handling systems. It serves as the primary logic device for E-stop circuits, ensuring that if a cable is cut or a contact welds, the system remains in a safe state and prevents an unexpected restart.

Professional FAQ

• What is the difference between the MSR127T and the MSR127R?

  The MSR127T (like this model) features an automatic/manual reset, whereas the MSR127R version specifically supports "Monitored Manual" reset for applications requiring a reset button to be pressed and released.

• Can this relay be used with OSSD outputs from a light curtain?

  Yes, the 440R-N23126 is designed to interface directly with the semiconductor (OSSD) outputs common on modern safety light curtains and laser scanners.