Overview
The Allen-Bradley 440R-N23135 Guardmaster MSR127RP safety relay delivers dependable fault detection for small to medium safety-critical applications. This single-function safety relay is designed to minimize downtime and is well-suited for relatively small safety applications and single zone control. Operating at 24V AC/DC with monitored manual reset in a 22.5mm housing width and CAT 4 rated output, the MSR127RP meets IEC 61508/61511 safety integrity requirements for emergency stop circuits, light curtain monitoring, and interlock applications.
Key Features
- Flexible Input Configuration: Can be connected in three different input wiring configurations: 1NC, 2NC, or with two PNP connections from a light curtain.
- Monitored Manual Reset: The MSR127RP unit has a monitored manual reset which offers checking of the output.
- Cross-Fault Detection: The MSR127RT checks for cross faults across the two inputs when connected in the 2NC configuration.
- CAT 4 Safety Rating: Provides the highest level of fault tolerance and diagnostic coverage for critical safety functions.
- Compact DIN-Rail Design: 22.5mm housing width enables space-efficient panel integration.
Technical Specifications
- Model: MSR127RP
- Part Number: 440R-N23135/C
- Supply Voltage: 24V AC/DC
- Input Configuration: 1 × 2NC or 1 × LC (Light Curtain)
- Safety Contact Output: 3 × N.O. (Normally Open)
- Auxiliary Contact: 1 × N.C. (Normally Closed)
- Reset Method: Monitored Manual Reset
- Safety Category: CAT 4 (ISO 13849-1)
- Housing Width: 22.5 mm
- Manufacturer: Rockwell Automation (Allen-Bradley)
- Mounting: DIN-Rail
- Certifications: IEC 61508, IEC 61511
Typical Applications
- Emergency stop and safety interlock circuits
- Light curtain and photoelectric sensor monitoring
- Presence detection and area guards
- Machinery safety control and personnel protection
- Single-channel safety logic for compact control systems
Compatibility & Replacements
The MSR127RP is part of the Guardmaster Minotaur 440R series and is compatible with standard Rockwell Automation safety relay sockets and DIN-rail configuration. This module can be paired with complementary Allen-Bradley safety control components including MSR family variants (MSR127TP, MSR127RT) for expanded dual-channel functionality. Verify control logic configuration when integrating with existing safety systems. The Series C revision ensures compatibility with recent safety protocol updates.
