The Allen-Bradley 440R-D22R2, also cataloged as the 440RD22R2 Safety Relay, operates as a dedicated hardware component for monitoring safety-related signal inputs within industrial control architectures.

Model Identification Matrix

• Series: Guardmaster
• Functional Class: Safety Monitoring Relay
• Input Configuration: Dual Channel
• Enclosure Type: DIN-rail Mountable

Hardware Specifications

Industrial Control Integration

The module is designed for I/O density scaling within safety-rated control circuits. By monitoring feedback from safety switches, E-stops, or light curtains, the relay manages state transitions with deterministic timing. Firmware flash compatibility and standardized backplane logic allow for seamless integration into safety networks where fail-safe signal processing is required to inhibit hazardous machine operation during fault conditions.

Ordering Info

1. 1 x 440R-D22R2 Safety Relay
2. 1 x Terminal block connector set
3. 1 x Technical manual

Field Installation Guidelines

• Mounting: Install the relay in an IP54 or higher rated cabinet to prevent ingress of conductive dust or moisture.
• Orientation: Mount vertically on a standard 35 mm DIN-rail to ensure adequate thermal convection across the heat-dissipating housing.
• Wiring: Ensure wire termination follows the marked schematic; verify that input signals are synchronized to prevent nuisance tripping of the safety circuit.
• Grounding: Maintain a low-impedance connection to the system ground bus to protect against transient voltage spikes.

Frequently Asked Questions

• What is the default state of the relay contacts?

  The internal safety contacts are normally open and close only when the input conditions are satisfied and the internal logic confirms no fault exists.

• Does this relay support manual or automatic reset?

  The relay configuration depends on the specific wiring of the reset loop; refer to the wiring diagram for configuring either monitored manual reset or automatic operation.

• How is the input signal monitored?

  The relay monitors the dual-channel inputs for cross-channel faults; a mismatch in timing between channels will prevent the output contacts from closing.

• Is the relay capable of hot-swapping?

  Hot-swapping is not supported; ensure all power is removed and the system is in a safe state before disconnecting or replacing the relay module.

• Can the relay be used with non-safety PLC signals?

  The relay is intended for safety-rated devices; signal compatibility must be verified to ensure the safety integrity level of the machine remains compliant.

• What is the maximum contact rating?

  The output contacts are rated for 3 A at 250 V AC or 30 V DC; do not exceed these values to prevent welding of the internal relay contacts.

• Is there a built-in diagnostic indicator?

  The front panel includes LED indicators that display the status of the power supply, safety inputs, and output contact state for simplified troubleshooting.

• What is the recommended wire gauge for connections?

  Use stranded or solid copper wire between 0.2 and 2.5 mm squared; ensure terminal screws are tightened to the torque specification in the manual.