An apparatus and method for identifying the current and voltage phase and terminal for power system devices is described. In one aspect of the present invention, the respective current phase and terminal of two current terminals is identified based on a known phase and known phase angle associated with a third current terminal at the location of the electrical power system. In another aspect of the present invention, the voltage phase and terminal is identified based on a known phase and known phase angle associated with a third current terminal at the location of the electrical power system. In another aspect of the present invention, the respective voltage phase and terminal of three voltage terminals is identified based on known phase and known phase angles associated with first and second current terminals at the location of the electrical power system.