Allen-Bradley 440R-D22R2 Guardmaster Dual Input Safety Relay

Allen-Bradley 440R-D22R2 Guardmaster Dual Input Safety Relay

Configured for dual safety-zone evaluation in Guardmaster safety control systems, the Allen-Bradley 440R-D22R2 (440R-D22R2 safety relay) provides selectable AND/OR logic, reset control, and relay-based safety outputs.

Hardware Specifications

Guardmaster Safety Logic and I/O Characteristics

The 440R-D22R2 provides two dual-channel universal safety inputs for separate safety zones.
Input compatibility includes normally closed devices, OSSD devices, and safety mat interfaces.
A front rotary selector configures the internal logical relationship between the two safety zones.
The selectable AND function requires both configured safety conditions to satisfy the relay logic.
The selectable OR function permits either configured safety condition to control the associated logic path.
Single Wire Safety supports cascading safety functions between compatible safety relays with reduced interconnection wiring.
The output stage provides two normally open electromechanical safety contacts and one auxiliary PNP output.
The auxiliary solid-state output supports continuous current up to 50 mA according to supplied specifications.
Reset configuration supports automatic/manual operation and monitored manual reset operation.

Frequently Asked Questions

Q: What supply voltage does the 440R-D22R2 require?
A: The relay operates from 24 VDC within the specified range of 20.4 to 26.4 VDC.

Q: What safety input devices can the relay monitor?
A: The two universal dual-channel inputs support N.C. devices, OSSD devices, and safety mats.

Q: Can the relay be mounted directly inside a control cabinet?
A: Yes. The supplied specifications identify 35 mm DIN rail mounting with IP40 enclosure protection and IP20 terminals.

Field Installation Guidelines

Mount the relay on a compatible 35 mm DIN rail with adequate clearance for terminal access and wiring.

Verify the 24 VDC supply remains within the specified 20.4 to 26.4 VDC operating range.

Separate safety input wiring from high-current conductors, motor cables, and switching circuits to reduce electrical interference.

Route OSSD and other safety-device conductors according to the connected device manufacturer's wiring requirements.

Terminate cable shields according to the applicable control-panel grounding scheme and avoid unintended shield current paths.

Use removable screw terminals with conductors secured against mechanical movement and accidental contact between adjacent circuits.

Configure the front rotary selector only after confirming the required AND or OR safety logic.

Select automatic/manual or monitored manual reset according to the safety circuit design and connected reset device.

Verify both safety channels independently during commissioning before placing the safety circuit into service.

Confirm each safety output changes state correctly when the corresponding safety input condition is interrupted.