säkring

Säkring is a protective device used in electrical installations to interrupt the flow of current if it becomes too high, protecting cables, appliances, and structures from damage due to overloads or short circuits.

A säkring consists of a conductive element that melts or fuses open when exposed to excessive current. It has ratings: current rating (amperes), voltage rating, and breaking capacity (the maximum fault current it can safely interrupt). Depending on design, it can be fast-acting (snabb) or time-delay (tidsfördröjd).

Forms: historically glass or ceramic cartridge fuses; modern versions include cartridge fuses and blade fuses. In household installations, fuses have largely been replaced by circuit breakers (brytare) in many countries, but fuses are still used in some appliances or older installations, and in vehicles.

Safety and replacement: only replace with the same type and rating; power should be off during replacement; improper replacement can cause overheating or fire. In many jurisdictions, installation and servicing must be performed by a qualified person.

In Swedish usage, säkring can also refer to protection or safety in a general sense, not only the specific fuse device. The term thus covers both the concrete protective component and broader notions of safeguarding.