If the appliances in a house were connected in series, turning off one would turn off the others. So, they are always connected in parallel. In a modern household wiring, a three-wiring system is used: the live or hot, neutral, and ground wires. Insulating plastic is color coded and is used to identify around the world. The live wire supplies the current to operate the appliance, while the current flows back through the neutral wire and completes the circuit. The neutral wire is connected to the ground wire. A short circuit occurs, when the live wire comes in contact with the neutral wire. This contact provides a low-resistance path, allowing a large current through the circuit that could lead to overcurrent and overheating. This can be avoided by using a fuse in series with the live wire. When the current exceeds a specific value, the fuse containing lead-tin alloy melts and breaks the circuit. This prevents the appliance from damage.