Question

Why should we use proper rating fuse in circuit

Answer 1

Answer:

The rule of thumb is that for every 20°C higher or lower in temperature, the fuse should be re-rated higher or lower 10-15%. Conversely, when a fuse is intended to be used in extreme low temperature conditions, the fuse must have a lower rating than that in normal conditions.

Answer 2

It is important to use a proper rating fuse for proper safety of the electrical wiring and the electrical equipment installed in any circuit. If the lower rating fuse is used it will blow off as soon as the circuit is switched on. On the other side, if the higher rating fuse is used then it won't blow off even if the current reaches the safety mark.

It could affect the electrical equipment in the circuit.

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A TV set works around 0.6-0.75A on a current. When a 5A fuse is mounted in your circuit, it won't blow off even though the 5A current flows through the device. However, the high current will damage the TV circuit. Therefore fuses of proper ratings should be used for proper safety of electrical appliances.