The EDWARDS SIGNALING INT-22.5R1-24 is an emergency stop safety relay that serves as a base device for emergency stop and safety gate applications. It is a two-channel safety switching device that performs self-monitoring on each ON-OFF cycle. The device conforms to EN 60204-1 and is equipped with positively driven relays. It is intended for monitoring connected switching elements on separating safety devices—such as protective screens, safety doors, enclosures, covers, and screens—and generating a safety-oriented output signal (enable). With a service life of 20 years and Safety Category 4 to EN 954-1, this device provides a robust foundation for functional machine safety.

A defining technical feature of the INT-22.5R1-24 is its flexible two-channel activation architecture. The device supports both equivalent and non-equivalent activation modes. With equivalent activation, safety channel CH1 is connected via positive potential while safety channel CH2 uses negative potential; cross monitoring is achieved through the short-circuit principle. With non-equivalent activation, both safety channels are connected to positive potential, and cross monitoring is achieved through functional diversity. This dual-mode capability allows the relay to be adapted to different safety sensor configurations and wiring schemes, providing system designers with valuable flexibility. A feedback circuit is included for monitoring external contactors (EDM), ensuring that any failure in the downstream power circuit is detected and the safety function is maintained.

The INT-22.5R1-24 offers comprehensive control over machine restart behavior. It supports both manual and automatic start modes. In manual start mode, after the safety inputs are closed, the reset button must be operated to close the enabling current paths—using either the falling edge of reset input S34 or the rising edge of reset input S35. Automatic start is configured by connecting reset input S35 to S33/S14. The device also incorporates critical safety lockout functions: starting lockout prevents the enabling paths from closing upon initial power-up until a deliberate reset action is performed, and restarting lockout prevents automatic restart after safety inputs have been opened and re-closed. These functions ensure that a machine cannot unexpectedly restart after a safety event or power interruption without explicit operator confirmation.

Installation is straightforward on a standard DIN rail. The device features a wide power supply range of 24-230V AC/DC with a start-up current of just 40mA. The housing is rated IP40 with terminals at IP20, and the device is designed to be installed inside a control cabinet with a minimum protection class of IP54. Front-panel LEDs provide clear visual status indication: a green SUPPLY LED confirms power supply, and two green LEDs indicate the status of relays K1 and K2. For applications requiring additional safe output contacts, the INT-22.5R1-24 can be paired with the INT-03 Safety Monitor Relay or INT-04 Emergency-Stop Safety Relay as contact expansion modules. With its combination of certified safety integrity, flexible activation modes, and robust lockout functions, the EDWARDS SIGNALING INT-22.5R1-24 is an ideal safety core for industrial machinery safeguarding.

Technical Specifications