Turvallisuusreläit

Turvallisuusreläit, or safety relays in English, are specialized electrical components designed to monitor safety-related functions in industrial automation systems. They play a critical role in protecting both personnel and machinery from hazardous situations. Unlike standard relays that are primarily used for control and switching, safety relays are built with enhanced reliability and redundancy features to ensure they function correctly even in the event of a single failure.

The fundamental purpose of a safety relay is to detect dangerous conditions, such as a safety gate being opened while a machine is in operation, or an emergency stop button being pressed. Upon detection of such a condition, the safety relay will immediately de-energize the hazardous parts of the machine, bringing it to a safe state. This prevents potential injuries to workers or damage to equipment.

Safety relays typically incorporate internal monitoring mechanisms, dual-channel inputs to detect discrepancies between signal paths, and force-guided contacts. Force-guided contacts are a key feature; they ensure that if one contact fails to open or close, the other contacts in the relay will not be able to move to their corresponding positions, thus preventing unintended operation. This mechanical linkage guarantees that the relay's internal contacts are always in a predictable state relative to each other.

These relays are often used in conjunction with safety sensors like emergency stop buttons, light curtains, safety mats, and door interlocks. They are integral to achieving compliance with various safety standards and regulations, such as ISO 13849 and IEC 62061, which govern the safety of machinery. Choosing the correct safety relay for a specific application depends on the required safety integrity level (SIL) or performance level (PL).