Why is fuse always connected to live wire?

What is the purpose of connecting a fuse to the live wire?

Why is it important for electrical safety mechanisms?

Answer:

Fuses are connected to the live wire to ensure effective engagement of electrical safety mechanisms in the event of a fault, such as insulation breakdown, to prevent fires and overheating.

Explanation: The reason a fuse is always connected to the live wire is to ensure that electrical safety mechanisms are effectively engaged in the event of a fault. The live wire, also referred to as the live/hot wire, is the conductor that supplies voltage and current to operate an appliance or circuit. When a fuse is installed on the live wire, it protects against thermal overload by breaking the circuit if excessive current flows through it. This action helps prevent overheating and potential fires.

In a three-wire system, the neutral wire is connected to the earth at both the voltage source and user location, making it zero volts and providing an alternative return path for the current. The case of the appliance is also grounded, ensuring it remains at zero volts. If there is any insulation breakdown in the live wire that causes it to contact the case, the intact earth/ground connection will cause the fuse or circuit breaker to trip, immediately disrupting the circuit and necessitating repair.

Wire insulation colors differ by region, so it is essential to check local codes to determine the correct wiring practices. Ground connections through the earth offer a low-resistance path and contribute to the overall safety of the electrical system. Meanwhile, the neutral wire is safe to touch even if its white insulation is compromised. Lastly, not all appliances require a three-prong plug; those with non-conducting cases that are doubly insulated may still use two-prong plugs, and modern outlets are designed to ensure correct connection.