A fuse used in series with an electric appliance limits the current through the appliance. Thus, it protects the appliance due to short-circuiting or overloading as when current exceeds the limit for which the fuse is rated, it blows off and the appliance is disconnected from the electirc supply. When a fuse with a defined rating for a particular appliance is replaced by one with larger rating, it does not blow off and the appliance is damaged due to larger current passing through it.
