Short circuits occur when a live wire comes into direct contact with a neutral wire. However, if the fuse does not blow and electricity continues to flow, the wires will get hot. The heat will then melt the outer plastic coating, which may cause it to catch on fire.
All wires which have electric current flowing through them have electrons moving through the wire. The reason for why wires heat up when a current flows through them is that a battery converts chemical energy into electric potential energy. This thermal energy causes the wire to heat up.
Overheating may be caused from any accidental fault of the circuit (such as short-circuit or spark-gap), or may be caused from a wrong design or manufacture (such as the lack of a proper heat dissipation system).
One may also ask, can heat damage wires? The heat doesn’t affect the copper conductors in the wiring. They can handle far higher temperatures than those found in attics. The problem is the plastic insulation and jacketing that surround the wires. These are usually rated to withstand up to 194°F, but temperatures that approach this limit are not recommended.
How hot does copper wire get?