Why nichrome wire cannot be used as a fuse wire?

15 Dec 2021

Why is nichrome wire unsuitable for use as a fuse wire?

Nichrome wire cannot be used as a fuse wire because it does not possess the property of low melting point required for an effective fuse.

Explanation:

Fuses play a critical role in electrical circuits as safety devices. When the current exceeds a safe limit due to a fault or overload, the fuse wire should melt, interrupting the circuit and preventing damage to connected devices and preventing the risk of fire. Nichrome wire is a nickel-chromium alloy known for its high melting point, typically around 1400 degrees Celsius. This high melting point is advantageous in applications where wires need to withstand high temperatures, such as in heating elements. However, it is a disadvantage when it comes to fuse applications. Fuse wires are deliberately made from materials with low melting points, such as copper or aluminum. Copper, for instance, melts at a relatively low temperature (around 1084 degrees Celsius), which means it will melt and break the circuit when exposed to excessive current, effectively protecting the electrical system. In summary, nichrome wire's high melting point disqualifies it from being used as a fuse wire, as it would not melt at the desired low current thresholds needed for effective circuit protection.

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