OVERVIEW

Official designation: Allen-Bradley 440R-EM4R2 (Guardmaster GSR EM Series, Safety Relay Expansion Module)

Role/Application: A safety expansion module used with a single wire safe base unit to easily extend the system with four instantaneous safety outputs, rated up to SIL 3/PLe.

KEY SPECS SUMMARY

Power: 24V DC (20.4V to 26.4V range)

Interfaces / Ports: Removable screw terminals

Indicators: PWR, SWS (Input/Link), O (Output) LEDs

Operating Temp: -5 to 55 degrees C

Platform / Compatibility: DIN rail mount, Single Wire Safe

Limit: 4 N.O. safety, 1 N.C. solid state auxiliary

Lifecycle: Active or mature, varies by model/revision

FREQUENTLY ASKED QUESTIONS

Technical Specifications:

Q: What is the maximum individual continuous current rating for each of the safety relay outputs?

A: The maximum continuous output current for each safety output is 2 Amps at 24V DC.

Wiring & Installation:

Q: What ventilation clearances are required when mounting this module on a DIN rail?

A: The unit must be mounted vertically with 37.4 millimeters (1.5 inches) clearance above and below.

Troubleshooting & Compatibility:

Q: What specific input technology does this expansion module use to connect to the base relay?

A: This module uses a Single Wire Safety (SWS) input for simple cascading from the primary relay.

Replacement & Upgrades:

Q: What is the typical width of this safety relay expansion module for panel space calculations?

A: The overall width of the 440R-EM4R2 module is 22.5 millimeters.