A circuit interrupter system, comprising: a circuit interrupter (4, 4') including a processing unit and an electronic trip unit, the circuit interrupter being configured to run a USB stack; characterised by one or more additional circuit interrupters (4, 4') including one or more additional processing units and one or more additional electronic trip units; and a portable computing device selectively and simultaneously connectable to the circuit interrupter (4, 4') through a first USB connection and the one or more additional circuit interrupters through one or more additional USB connections, the portable computing device being structured to function as a USB host and to implement a graphical user interface for enabling communication between the portable computing device and the processing unit of the circuit interrupter when the portable computing device is connected to the circuit interrupter through the first USB connection and for enabling communication between the portable computing device and the one or more additional processing units of the circuit interrupter when the portable computing device is connected to the one or more additional circuit interrupters through the one or more additional USB connections, wherein the graphical user interface is configured to enable one or more first functional trip settings of the electronic trip unit and one or more additional functional trip settings of the one or more additional circuit interrupters to be simultaneously adjusted using a single settings screen of the graphical user interface when the portable computing device is simultaneously connected to the circuit interrupter and to the one or more additional circuit interrupters, thereby enabling the portable computing device to perform selective coordination among the circuit interrupter and the one or more additional circuit interrupters. a circuit interrupter (4, 4') including a processing unit and an electronic trip unit, the circuit interrupter being configured to run a USB stack; characterised by one or more additional circuit interrupters (4, 4') including one or more additional processing units and one or more additional electronic trip units; and a portable computing device selectively and simultaneously connectable to the circuit interrupter (4, 4') through a first USB connection and the one or more additional circuit interrupters through one or more additional USB connections, the portable computing device being structured to function as a USB host and to implement a graphical user interface for enabling communication between the portable computing device and the processing unit of the circuit interrupter when the portable computing device is connected to the circuit interrupter through the first USB connection and for enabling communication between the portable computing device and the one or more additional processing units of the circuit interrupter when the portable computing device is connected to the one or more additional circuit interrupters through the one or more additional USB connections, wherein the graphical user interface is configured to enable one or more first functional trip settings of the electronic trip unit and one or more additional functional trip settings of the one or more additional circuit interrupters to be simultaneously adjusted using a single settings screen of the graphical user interface when the portable computing device is simultaneously connected to the circuit interrupter and to the one or more additional circuit interrupters, thereby enabling the portable computing device to perform selective coordination among the circuit interrupter and the one or more additional circuit interrupters.