A circuit breaker includes at least one set of breaker contacts and a contact actuating mechanism configured to open and close the at least one set of contacts. The circuit breaker further includes a polarity sensitive shunt trip mechanism mechanically coupled to the contact actuating mechanism and configured to lock the contact actuating mechanism responsive to a shunt trip voltage of a first polarity to prevent closing of the at least one set of contacts and to unlock the contact actuating mechanism responsive to a shunt trip voltage of a second polarity to enable closing of the at least one set of breaker contacts.