A system comprising: an electrical panel comprising an enclosure enclosing one or more circuit breakers; and an energized parts guard configured to be installed on the electrical panel and comprising a panel of substantially rigid, electrically insulative material wherein the substantially rigid panel further comprises a first one or more apertures; wherein the first one or more apertures are so dimensioned to accept the one or more circuit breakers inserted into the first one or more apertures when the energized parts guard is installed on the electrical panel such that there is less than a 12.5 mm gap between the panel and the circuit breaker on at least two sides of the one or more circuit breakers; characterised by: the substantially rigid panel further comprising a second one or more apertures; and in that: the energized parts guard further comprises electrically insulating covers for the second one or more apertures; the second one or more apertures are aligned with at least one terminal of the one or more circuit breakers when the energized parts guard is installed on the electrical panel and when the one or more circuit breakers are inserted into the first one or more apertures to facilitate access to the at least one terminal; and the insulating covers interlock with the one or more circuit breakers, preventing access to the circuit-breaker terminals unless the circuit breakers are in the open position. an electrical panel comprising an enclosure enclosing one or more circuit breakers; and an energized parts guard configured to be installed on the electrical panel and comprising a panel of substantially rigid, electrically insulative material wherein the substantially rigid panel further comprises a first one or more apertures; wherein the first one or more apertures are so dimensioned to accept the one or more circuit breakers inserted into the first one or more apertures when the energized parts guard is installed on the electrical panel such that there is less than a 12.5 mm gap between the panel and the circuit breaker on at least two sides of the one or more circuit breakers; characterised by: the substantially rigid panel further comprising a second one or more apertures; and in that: the energized parts guard further comprises electrically insulating covers for the second one or more apertures; the second one or more apertures are aligned with at least one terminal of the one or more circuit breakers when the energized parts guard is installed on the electrical panel and when the one or more circuit breakers are inserted into the first one or more apertures to facilitate access to the at least one terminal; and the insulating covers interlock with the one or more circuit breakers, preventing access to the circuit-breaker terminals unless the circuit breakers are in the open position. the substantially rigid panel further comprising a second one or more apertures; and in that: the energized parts guard further comprises electrically insulating covers for the second one or more apertures; the second one or more apertures are aligned with at least one terminal of the one or more circuit breakers when the energized parts guard is installed on the electrical panel and when the one or more circuit breakers are inserted into the first one or more apertures to facilitate access to the at least one terminal; and the insulating covers interlock with the one or more circuit breakers, preventing access to the circuit-breaker terminals unless the circuit breakers are in the open position. the energized parts guard further comprises electrically insulating covers for the second one or more apertures; the second one or more apertures are aligned with at least one terminal of the one or more circuit breakers when the energized parts guard is installed on the electrical panel and when the one or more circuit breakers are inserted into the first one or more apertures to facilitate access to the at least one terminal; and the insulating covers interlock with the one or more circuit breakers, preventing access to the circuit-breaker terminals unless the circuit breakers are in the open position.