Low voltage (600 Volts and below) overcurrent protection is achieved through the use of circuit interruption devices which both detect and interrupt the flow of circuit overcurrents.

While solid-state “black box” protection may be uniquely configured to protect an electrical circuit, generally available standard low voltage protection devices are fuses and circuit breakers, in the form of: thermal circuit breakers, magnetic circuit breakers and thermal-magnetic circuit breakers.  The following article link is offered to assist one’s understanding of the differences in these devices.

http://www.mechprod.com/circuit-protection---types/

The article provides a good basic overview of the benefits and shortcomings in using each type of device.  Cost, size, and application benefits and limitations are among the considered attributes.