Piirikytkimiä

Piirikytkin, often translated as circuit breaker, is an automatic electrical switch designed to protect an electrical circuit from damage caused by overcurrent or short circuit. Its basic function is to interrupt the current flow when a fault condition is detected.

The core principle behind a piirikytkin involves a bimetallic strip or an electromagnet. In thermal piirikytkimiä, an overcurrent causes a bimetallic strip to heat up and bend. This bending action eventually triggers a mechanism that opens the switch, interrupting the circuit. In magnetic piirikytkimiä, a strong electromagnet is used. When a sudden surge of current occurs, the magnetic field generated by the electromagnet becomes strong enough to pull a lever, which opens the switch. Many piirikytkimiä incorporate both thermal and magnetic tripping mechanisms for enhanced protection.

Piirikytkimiä are essential safety devices in virtually all electrical installations, from residential homes to industrial facilities. They replace older fuse technology because they can be reset after a fault, whereas fuses must be replaced. They provide reliable protection against electrical fires and damage to equipment. Different types of piirikytkimiä exist, designed for various voltage and current ratings, and specific applications like protecting sensitive electronics or high-power industrial machinery. Their presence significantly enhances electrical safety and system reliability.