Circuit Protection

ABB MCB
Science Technology
How does an MCB work?
This excerpt from ABB introduces the technology inside and miniature circuit breaker (MCB). What does an MCB do? The short answer: it protects wires from overloads and short-circuits. When we look on the inside of an MCB we can see how that actually works. For overload protection the temperature of a bimetal, through which the current passes (yellow area), is decisive. If the nominal current—the current the circuit breaker is…