Low Voltage Electrical distribution systems further facilitate the economic and safe delivery of adequate electrical power to all the electrical equipment used in commercial building, or industrial facility. The transmitted power arrives first at an electric distribution substation, where it is passed through a series of step-down transformers that again lower the voltage to more usable levels. Finally, the usable electricity enters the building at a single point known as the service entrance. Power enters through a main device (circuit breaker or fusible switch) located within an electrical assembly referred to as the service entrance electrical distribution equipment.