What is the difference between load and line wires?
A load is a device that consumes electricity. A line wire is a conductor, or wire, transmitting an electric current from one place to another.
Wires carry electrical energy from source to destination. Loads use the power as an energy input and do not transmit it onwards (to other loads). In single-phase alternating current circuits, wires are connected between the live wire of the system and a ground point called neutral–hence “line” or “neutral”. In three phase AC circuits, only one of two opposing live wires is grounded per phase (i.e., all equipment connections in these systems are 240 volts). The third line/phase of these systems has no connection at its end so if voltage were lost on this line/phase the live wires would not be grounded.