A polarity detector is configured to detect whether a polarity of one of the secondary direct current terminals is reversed in polarity consistent with an improper connection of a removable load or the removable direct current energy source to the secondary direct current terminals. A protection module or transient clamp comprises a protection semiconductor switch with protection switched terminals and a protection control terminal. A controller is configured to control a plurality of switches of the circuit breaker and the protection module via a driver. Further, the controller is configured to open or activate the circuit breaker responsive to a signal or data message of the polarity detector detecting the improper connection.