Service Drop Conductors
Service drop conductors are generally run with cables called triplex or quadraplex and are usually made of aluminum. Triplex cable is usually used for overhead single phase service. Triplex cable contains three individual wires twisted around each other: two insulated conductors called the "hot" legs of the service and a bare or uninsulated wire which is the neutral wire of the service. If a circuit is connected between the two hot legs, the circuit voltage is 240 volts. If a circuit is connected between the neutral and either hot leg of the service, the circuit voltage will be 120 volts.
Quadraplex cable contains four individual wires and is commonly used for overhead three phase service drops. The three insulated conductors correspond to the three phases, commonly referred to as Phase A, phase B, and phase C. The neutral in triplex and quadraplex cable is often bare and grounded at the transformer and electric meter. It is also very common for the neutral to be a smaller wire gauge size than the hot or phase conductors.
Underground service drops utilize special insulated cable approved for direct burial or may be installed in conduit so the cable can be replaced without extensive digging.