Thermal magnetic circuit breakers are devices that provide protection against overcurrent in circuits. Circuit breakers use an automatically operated electrical switch to disrupt the flow of current when an overload or short circuit is detected. Thermal magnetic circuit breakers do this using an electromagnet and bimetallic strips.
Circuit breakers provide more sophisticated protection against overcurrent than a simple fuse. Fuses simply burn out and have to be replaced, whereas circuit breakers just need to be reset.
How do thermal magnetic circuit breakers work?
In thermal magnetic circuit breakers, there are two ways the flow of current might be detected and disrupted. In the event of a short circuit, the electromagnet rapidly trips the switch. If the overload is smaller, over a longer period of time, the bimetallic strips will instead eventually react to trip the switch.
What are thermal magnetic circuit breakers used for?
Thermal magnetic circuit breakers are most often used in distribution boards. They make up part of the subsidiary circuits in the broader electrical supply system, protecting against overcurrent.