Wiki User
∙ 11y agoNo ( you can start a fire )
Wiki User
∙ 11y agoIt is ok to use a fuse with a higher amperage rating and not ok to use a fuse with a smaller amperage rating why?
No, a fuse of a higher amperage rating will not usually have a higher melting point link. The higher amperage fuse will use a wider link or a link of larger diameter.
The fuse is supposed to be the weakest link in the circuit. The circuit is rated to handle a specific load current. The wire and insulation rating of the circuit is governed by this specific load. If this load malfunctions and the load current becomes higher that what is specified, the fuse is there to break the circuit. A fuse of a higher rating than what is called for will allow a higher current to flow through the circuit which could cause the insulation on the wire to melt, the wire to burn open or components in the circuit to become unusable. Never over fuse an electrical circuit with a larger amp rated fuse.
It is not safe or recommended to replace a low voltage fuse with a high voltage fuse. The fuse should always match or exceed the voltage rating of the circuit it is protecting. Using a high voltage fuse in a low voltage circuit can lead to overcurrent, equipment damage, or in extreme cases, fire hazards. Always use the correct rated fuse for your circuit.
Using a higher rated fuse is not recommended. For example, using a 13 amp fuse on a radio rated for 3 amps, means that, in the case of a short, components would burnout before the fuse, so damaging the radio, probably beyond repair. The same care should be taken with household mains electricity. In the UK (240 volts) the light circuits (usually one upstairs and one downstairs) take 5 amp fuses.
The fuse is rated to protect the equipment, the supply, and you. Change the fuse for a higher rating and you compromise your safety and equipment and supply safety; increasing the risk of electric shock and of fire.
Using a fuse correctly rated for current but "overrated" for voltage does not present a problem. Current ratings are critical safety issues, and fuses should be replaced with those of the same current rating. But using a fuse with an identical current rating but a higher voltage rating is not a problem. The reason for that lies in what the voltage rating of a fuse is. Fuses are given a voltage rating to state a maximum voltage in a circuit that they are designed to protect. And the voltage rating has nothing to do with the "normal" operation of the fuse. The fuse carries current when it operates normally, but when something happens and excessive current flows, the fusible link heats up and opens. This is where the voltage rating comes into play. It is possible that a fuse can arc through when it fails. It is the voltage rating that stands in the way of this. As long as the voltage rating of a circuit is not beyond the voltage rating of the fuse, that fuse will fail safely when it fails. It is acceptable to use a fuse of an equal current rating but a higher voltage rating when replacing a fuse that has failed.
If it fits you are fine. You are at the same current and the voltage rating is higher.
It should be, yes. Never higher.
Yes, a 250V fuse can replace a 125V fuse if they have the same ampacity rating. The voltage rating is simply the maximum voltage that the fuse is capable of safely interrupting. You can go higher, but you can not go lower. Obviously, the form factor of the fuse must be the same, but that is often the case.
That would depend. On most cars the fuse is rated for operation at 12 VDC, but that is an almost meaningless rating. Right all cars are 12v and it does not matter! What matters is the current rating of the fuse. Never use a higher rated fuse. Use what the book calls for so you don't fry anything if you have a short or such. An auto store or the dealer should tell you what fuse you need. One call, that's all!
To calculate the fuse rating level, you typically want to choose a fuse that is slightly higher than the full-load current to avoid nuisance tripping. For a full load of 4 amps, you could choose a fuse rating of 5 or 6 amps.