embodiments include a circuit breaker having first and second electrical contacts , the contacts adapted to generate an electrical arc during separation , at least one of the first and second electrical contacts being a movable electrical contact . the circuit breaker also includes an expansion chamber disposed adjacent to at least one of the first and second electrical contacts such that an arcing space is defined by the first electrical contact and the second electrical contact when the first and second electrical contacts are separated . the expansion chamber includes an opening configured to permit air flow between the arcing space and a chamber of the expansion chamber .