Katkojärjestelmiä

Katkojärjestelmiä, known in English as circuit breakers, are essential safety devices in electrical systems. Their primary function is to protect electrical equipment from damage caused by overcurrents. Overcurrents can arise from two main sources: overloads and short circuits. An overload occurs when too many appliances are connected to a single circuit, drawing more current than it is designed to handle. A short circuit is a more severe fault, typically caused by damaged insulation, where a low-resistance path allows a very large current to flow.

When an overcurrent is detected, the circuit breaker automatically interrupts the flow of electricity, thereby preventing overheating of wires and potential fires. This interruption is achieved by a mechanical switch that opens the circuit. The mechanism can be activated by thermal means, where a bimetallic strip bends due to heat generated by the overcurrent, or by magnetic means, where an electromagnet is energized by the excessive current, causing it to trip. Some breakers utilize both methods for enhanced protection.

Circuit breakers replace older, less convenient safety devices like fuses. Unlike fuses, which must be replaced after they "blow," circuit breakers can be reset manually after the fault condition has been cleared. This makes them more practical and cost-effective for repeated use. They are widely used in homes, businesses, and industrial settings to safeguard electrical infrastructure and the people who use it. Different types of circuit breakers exist, designed for various voltage levels and current capacities, ensuring appropriate protection for diverse applications.