Allen-Bradley 440R-D22S2 Guardmaster GSR Safety Relay

The Allen-Bradley 440R-D22S2 is a Guardmaster GSR (Guardmaster Safety Relay) designed for emergency stop and safety gate monitoring in industrial machinery. It features 2 safety outputs (normally open, 6 A), 2 auxiliary outputs (solid-state), and a 24V DC power supply. The relay supports single or dual-channel operation with cross-circuit detection. It is certified to Category 4, Performance Level e (ISO 13849-1) and SIL3 (IEC 61508). The 440R-D22S2 includes an integrated reset (automatic or monitored manual) and feedback (EDM) monitoring. The module is 45 mm wide and DIN rail mountable.

Technical Specifications

Supply voltage: 24 V DC (19.2-28.8 V). Power consumption: 2 W. Safety outputs: 2 NO (force-guided relays), 6 A at 230 V AC / 24 V DC (AC-15/DC-13). Auxiliary outputs: 2 solid-state (PNP, 0.1 A). Inputs: 2 safety channels (S11/S12, S21/S22), reset input (S33/S34), feedback input (S35). Response time: ≤ 25 ms. Operating modes: single or dual-channel, automatic or monitored manual reset. Diagnostics: LED indicators for power, input status, output status, and fault. Dimensions: 45 mm (W) × 100 mm (H) × 115 mm (D). Weight: 0.2 kg. Operating temperature: -10°C to 55°C. Storage: -40°C to 85°C. Protection: IP20. Certifications: CE, UL, TÜV, RoHS.

Key Features

• 2 safety NO relay outputs (6 A)

• 2 solid-state auxiliary outputs (PNP)

• Single or dual-channel input configuration

• Cross-circuit detection

• Monitored manual or automatic reset

• Feedback (EDM) monitoring for external contactors

• LED indicators for all I/O and fault

• Removable screw terminals

Safety Functions

The 440R-D22S2 is used to monitor emergency stop buttons, interlocking gates, light curtains, and safety mats. In dual-channel mode, it detects cross-shorts and opens the safety outputs within 25 ms. The monitored manual reset ensures the reset button is not shorted and that external contactors have properly de-energized before restarting.

Installation and Wiring

Mount the relay on a 35 mm DIN rail. Connect 24V DC to A1/A2. Wire safety inputs: emergency stop contacts to S11/S12 and S21/S22. For single-channel, use only S11/S12. For reset, connect a normally open button between S33 and S34. For feedback, connect external contactor auxiliary contacts (normally closed) between S35 and S24. Safety outputs connect to contactor coils. Auxiliary outputs (Y0, Y1) provide status to a PLC. All wiring must comply with EN 60204-1.

Configuration

Configuration is via DIP switches on the front. Switch 1: single/dual channel. Switch 2: automatic/manual reset. Switch 3: feedback enabled/disabled. Switch 4: cross-circuit detection on/off (for dual-channel). The relay reads the switches at power-up.

Maintenance and Diagnostics

LEDs: green (PWR), yellow (IN1, IN2), green (OUT), red (FAULT). If the red LED flashes, check the error code: 1 flash = reset circuit shorted, 2 flashes = cross-circuit, etc. The relay requires no routine maintenance. Test the safety function monthly.

Conclusion

The Allen-Bradley 440R-D22S2 Guardmaster GSR safety relay offers a compact, high-integrity solution for machine safety circuits. Its dual safety outputs, auxiliary outputs, and configurable inputs make it suitable for a wide range of emergency stop and guard monitoring applications.