Safety Coupling Relays – Reliable Signal Transmission in Safety-Critical Applications

In the process industry, the safe coupling of output signals, such as those from a safety controller, to the periphery is of critical importance. Conventional coupling relays cannot be used in these scenarios, as they interrupt the safety chain, thereby compromising the ability to ensure a safe shutdown in the event of a hazard.

The solution is the use of safety coupling relays, which are specifically designed for safety-critical applications. These relays are built redundantly and feature self-monitoring. As a result, they enable the standard-compliant coupling of safety-related signals up to the highest safety levels of SIL 3 and PL e.

Typical applications of safety coupling relays include:

• Galvanically isolated coupling of 24V digital signals to 230V – Protects control components and prevents disturbances caused by overvoltage.
• Safe coupling of sensor signals to the controller – Enables the connection of safety-related sensors, such as pressure monitors or limit switches, to the control system.
• Contact amplification for controllers with limited output power – Ensures that connected loads are reliably switched even when the control system has limited power capacity.
• Filtering of test pulses sent by safety controllers – Prevents false alarms by recognizing and filtering test pulses sent by the safety controller.

Safety coupling relays are essential when safe shutdowns and compliance with the highest safety standards are required. Their use ensures the reliable transmission of safety-critical signals without compromising the integrity of the safety chain.

Technical Data:

• Safety Levels: Up to SIL 3 / PL e
• Redundancy: Redundant relays with self-monitoring
• Signal Transmission: Galvanically isolated coupling of 24V to 230V
• Functions:
- Safe coupling of sensor signals (e.g., pressure monitors)
- Contact amplification for controllers with limited output power
- Filtering of test pulses from safety controllers

• Applications: Process industry, mechanical engineering, safety control systems