Why should a 5-ampere fuse never be replaced with a 20-ampere fuse?

A fuse is designed to protect a circuit by breaking the electrical connection when the current exceeds a safe level. If a circuit is designed for a maximum of 5 amperes, its wiring and components can only safely handle up to that amount of current. Replacing a 5-ampere fuse with a 20-ampere fuse completely removes this intended protection. If a short circuit or fault occurs, the circuit could draw up to 20 amperes before the fuse blows, causing the thinner wires and fragile components to overheat, melt, or start a fire. Distractors claiming the larger fuse would blow easier, or mentioning power supply ripple and voltage drop, are incorrect. The primary purpose of a fuse is strictly for overcurrent protection to prevent fires and catastrophic equipment damage.