Fuses are small, simple components—but misunderstanding them can lead to equipment damage, fire risk and serious safety issues.

Let’s clear up some of the most common fuse myths and explain why believing them can be dangerous.

Myth #1: "Any fuse with the same voltage rating will work"

The truth: You do need to ensure that the voltage rating of the fuse is equivalent to or higher than the voltage rating of the circuit.

However, the current rating matters just as much - often more - because it determines the practical performance of the fuse.

Using a fuse with a higher current rating than specified can allow excessive current to flow, overheating wires and damaging components before the fuse opens.

Using a fuse with a lower current rating than specified may result in premature opening of the circuit (nuisance blowing).

Why it’s dangerous: The circuit will not be protected as intended.

Myth #2: "A bigger fuse means better protection"

The truth: By ‘bigger’, most people are referring to fuses with a higher current rating.

Oversizing a fuse rating prevents or delays interruption during a fault. The result can be melted insulation, destroyed electronics, or even fire.

This is not achieving what the fuse was intended to do – choosing higher current rated fuse protect less—not more.

Why it’s dangerous: Damage occurs before the fuse reacts.

Myth #3: "Fast-acting and time-delay fuses are interchangeable"

The truth: They are designed for very different applications.

Fast-acting fuses protect sensitive components.

Time-delay fuses are designed to tolerate temporary in-rush currents as experienced in applications featuring motors, pumps, fans & transformers.

Why it’s dangerous: The wrong type can cause nuisance blowing—or fail to protect during a real fault.

Myth #4: "If a fuse keeps blowing, the fuse is the problem"

The truth: If the fuse keeps blowing, this is a certain indication that the circuit is experiencing an overcurrent. The fuse is doing its job! A blown fuse is usually a symptom, not the cause.

Repeated failures often point to overloads, short circuits, aging components, or incorrect fuse selection.

Why it’s dangerous: Replacing fuses without fixing the root issue invites the possibility of more serious overcurrent scenarios.

Myth #5: "Replacing a fuse with wire or foil is an easy fix"

The truth: This removes proper protection entirely!

Makeshift "repairs" turn the fuse holder into a direct conductor—allowing unlimited current until something else fails.

Why it’s dangerous: The circuit has had its safety feature completely removed. High risk of fire, equipment destruction and personal injury. Never do this!

Myth #6: "All fuses perform the same at their rated current"

The truth: The performance of a given fuse is dependent on its time-current curve and performance designation.

There can be enormous variance between fuses that look similar and have the same current rating.

Two fuses with the same current rating can behave very differently during overloads and short circuits as they may be designed for completely different applications or electrical environments.

Why it’s dangerous: Assuming equivalence can lead to incorrect & inadequate protection.

The Takeaway

Fuses are precision safety devices—not placeholders.

Choosing the correct type, rating, and speed is essential to protecting both equipment and people.

When in doubt:

✔ Match current and voltage ratings

✔ Select the correct performance designation

✔ Investigate repeated failures

✔ Never bypass protection

Why Fuseco?

Fuseco are experts at identifying fuses and we love to help our customers identify fuses & find replacements.

If you’re trying to identify a fuse, please contact the experts at FUSECO. We have 30 years of experience specialising in electrical products. Our friendly staff members will be willing to help you identify exactly what fuse you need.

Call us today for a quote and let FUSECO become your No.1 supplier of fuses!