Allen Bradley 440R-D23171 Safety Relay – MSR125HP, 24V DC, 4 N.O. Safety Outputs, Two-Hand Control, Automatic/Manual Reset, Removable Terminals

The Allen Bradley 440R-D23171 (MSR125HP) is a Guardmaster safety relay designed specifically for two-hand control monitoring applications. Operating at 24V DC, this high-integrity relay provides four normally open (N.O.) safety contacts for immediate output control, ensuring operator safety in press and machinery operations that require simultaneous activation of two control buttons.

With support for both automatic and manual reset functions, the MSR125HP enables flexible configuration to meet varying safety and production requirements. It conforms to Performance Level “e” (EN ISO 13849-1) and SIL 3 (IEC 61508) standards, offering top-tier protection for high-risk industrial environments. The plug-in removable terminals make wiring, testing, and maintenance fast and efficient, while its compact 22.5mm design saves valuable space in control panels.

Technical Specifications

Model: 440R-D23171 Allen Bradley
Series: Guardmaster MSR
Product Type: Two-Hand Control Safety Relay
Supply Voltage: 24V DC (AC/DC compatible)
Voltage Type: AC/DC
Safety Outputs: 4 N.O. contacts
Auxiliary Outputs: None
Input Type: Dual control channels (two-hand operation)
Reset Function: Automatic or Manual selectable
Performance Level (EN ISO 13849-1): Level e
SIL (IEC 61508): SIL 3
Stop Category (IEC 60204): 0
Mounting Type: DIN Rail (35mm top hat)
Connection Type: Plug-in removable terminals
Dimensions (W x H x D): 22.5 x 114.5 x 99 mm

Electrical & Performance Details

• Supply Voltage Range: 24V DC ±10%
• Output Configuration: 4 N.O. safety contacts (immediate switching)
• Input Type: Dual-channel (two-hand control inputs)
• Reset Function: Selectable automatic or manual
• Safety Category: Category 4 / Performance Level e
• Stop Function: Category 0 (instantaneous stop)
• SIL Rating: SIL 3 according to IEC 61508
• Feedback Circuit: Yes (for contactor monitoring)
• Start Input: Yes (monitored start supported)
• Muting Function: No

Mechanical Specifications

• Width: 22.5 mm
• Height: 114.5 mm
• Depth: 99 mm
• Mounting: 35mm DIN Rail
• Connection Type: Plug-in removable terminals
• Housing Type: Compact industrial-grade enclosure

Environmental & Application Suitability

• Typical Applications: Press control, cutting machinery, stamping operations, and dual-operator stations
• Monitoring Capability: Two-hand operation with input timing control for safety verification
• Stop Function: Category 0 (immediate power interruption)
• Suitable For: Two-hand control systems and operator safety circuits
• Installation Environment: Industrial machinery and control cabinets

Compliance & Certifications

• Performance Level: PL e (EN ISO 13849-1)
• SIL Rating: SIL 3 (IEC 61508)
• Safety Category: Category 4 (IEC 62061)
• Stop Category: 0 (IEC 60204)
• UL / cUL Listed: Yes
• CE Marked: Yes
• BG BIA Approved: Yes
• RoHS Compliant: Yes

Key Features & Benefits

✅ Four safety outputs provide redundancy and high reliability.

✅ Two-hand control input ensures operator safety during machine actuation.

✅ Performance Level e / SIL 3 guarantees the highest functional safety integrity.

✅ Automatic or manual reset supports flexible control configurations.

✅ Compact 22.5mm housing saves valuable panel space.

✅ Removable plug-in terminals simplify wiring and maintenance.

✅ Category 0 stop function enables immediate machine shutdown for safety.

📦 Order the Allen Bradley 440R-D23171 from Drive Outlet Megastore

At Drive Outlet Megastore we offer unbeatable Allen Bradley 440R-D23171 prices, with fast UK & EU delivery and expert support for Guardmaster MSR safety relays and two-hand control systems.

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Ensure maximum operator safety with the Allen Bradley MSR125HP — engineered for precision two-hand control applications, available exclusively from Drive Outlet Megastore.