interlockkytkimiin

Interlockkytkimet (interlock switches) are safety devices that detect whether a machine guarding element, such as a door, gate, or access panel, is fully closed and latched. Their primary purpose is to prevent machine start-up or to stop a running machine if the guard is opened, thereby reducing the risk of injury to operators and bystanders.

Common types include mechanical interlocks (latching and non-latching), magnetic interlocks, and electrical contact interlocks. Mechanical interlocks rely on a physical latch and a keeper, while magnetic interlocks use magnets to sense the door position. Some interlocks include tamper-detection or auto-checking features. They are typically installed on guards and connected to the machine's safety circuit.

In safety circuits, interlock switches are used with safety relays or safety controllers and are designed with two-channel (redundant) monitoring and positive-opening contacts to fail safe. When the guard opens, the contacts change state, triggering a safe stop. Proper wiring often differentiates between safety contacts (for guarding) and auxiliary contacts (for indication or control logic).

Standards and guidance for interlock switches emphasize reliable design and performance. ISO 14119 (Safety of machinery — Interlocking devices associated with guards) specifies requirements for design and verification; IEC 62061 and ISO 13849-1 address functional safety of electrical control systems that use interlocks. Compliance helps ensure consistent safety levels, documentation, and maintenance requirements.

Applications include manufacturing lines, packaging, food and beverage, robotics, and any equipment with guarded access. Installation considerations include choosing the correct actuation method, ensuring guard integrity, routine testing of the safety function, and replacement with compatible safety-rated components over time.