The current in a circuit depends on the rating of the appliances connected to it. The choice of wires depends upon the maximum current estimated to pass through them. If the total power rating of the appliances exceeds this permitted limit, they tend to draw a large current. This is known as overloading due to excessive heating takes place.

Overloading occurs when too many appliances are connected in a single socket or live and neutral wires come in contact with each other.