Which of the following is NOT a classification of circuit breakers?

Solid-state circuit breakers are not classified in the same way as oil, air, or gas circuit breakers. Circuit breakers are categorized based on the medium they use to quench the electrical arc formed when the circuit breaks.

Oil circuit breakers utilize oil as an insulating medium and for arc extinction. Air circuit breakers rely on air to cool and extinguish the arc that forms when interrupting the current. Gas circuit breakers, on the other hand, typically use sulfur hexafluoride (SF6) gas, which has excellent insulating and arc-extinguishing properties.

Solid-state devices, while they can function in a capacity similar to circuit breakers, do not rely on these physical mediums to interrupt the circuit. Instead, they use semiconductor technology to control and manage electrical flow. Therefore, determining that solid-state is not under the traditional classifications reinforces the understanding of how these types differ based on their operational characteristics and the environments in which they are used.