What Material Is The Fuse Made Of?
Aug 02, 2023
A fuse is also called a fuse, which is defined as a "fuse link" by international standards. It is an electrical component installed in a circuit to ensure the safe operation of the circuit. Nowadays, as products become smaller and more integrated, the shape and size of fuses are also very different from traditional fuses. For example, fuses for mobile phones must conform to the trend of fast charging and must withstand large instantaneous currents. To achieve its protective function, the requirements for fuses are getting higher and higher. So what material is the fuse made of? Can it be replaced by copper wire? Let's take a look together:
1. Production materials
The fuse must be a metal wire that is easy to melt so that it can be blown in time when the current is large, so as to play a protective role, lead-antimony alloy wire is usually used. The fuse material is mainly made of low melting point alloys such as aluminum antimony alloy. The main element of aluminum-magnesium alloy aluminum plate is aluminum, and a small amount of magnesium or other metal materials are added to strengthen its hardness. The aluminum alloy with Mg as the main additive element is also called anti-rust aluminum alloy because of its good corrosion resistance.
Because it is metal itself, its thermal conductivity and strength are particularly outstanding. The aluminum-magnesium alloy aluminum plate is light in weight, low in density, good in heat dissipation, and strong in compression resistance, which can fully meet the requirements of 3C products for high integration, lightness, miniaturization, impact resistance, electromagnetic shielding, and heat dissipation. It is several times stiffer than traditional plastic cases, yet only one-third the weight.
2. Can the copper wire be used instead?
Generally speaking, it is not possible, because the resistance of the copper wire is small, so the internal energy generated when the current passes is small, and the melting point of copper is relatively high. Without the function of the protection circuit, it is easy to cause the fuse to blow.
It can be used as a temporary emergency. One major premise is that you must pay attention to the allowable current value of the circuit, the allowable current of the copper wire, and the fusing current. But it must not be used for a long time, otherwise, there will be a safety hazard of overload, which may easily cause a short-circuit fire. The reason why fuses use metals with low melting points such as lead and tin is that they can protect electrical equipment and electrical circuits. When the current load is too large, the circuit may be destroyed. However, if a lead-tin fuse is used, its melting point is low, and when the current is too large, it will be blown to protect the electrical appliance. The melting point of copper wire is much higher than that of lead and tin, and it will not fuse when the current is large, which will damage electrical appliances. If you can't find it temporarily, you can use copper wire to replace it temporarily, but you should replace it as soon as possible after you find it.
Therefore, in the electrical safety regulations, it is forbidden to use copper wire, iron wire, and aluminum wire instead of fuses. Because ordinary electricians, or some people who do not understand, blindly connect the core or iron wire of ordinary wires to the switch knife and use it. When the circuit is overloaded, the switch knife loses its insurance function, causing the line to catch fire. It is not uncommon for the ammeter to burn out and cause serious accidents; if there is a short circuit in the circuit, it is even more dangerous. When the switch is turned on, the arc will seriously burn the operator and even cause fatal accidents. Therefore, the current electrical safety technical regulations still have: In any case It is never allowed to use copper wire and iron wire instead of fuse.
3. Precautions
(1) Do not use a fuse that is too thin. If a fuse is too thin, the normal current passing through it will easily blow out, causing unnecessary power outages;
(2) A suitable fuse must be selected and used. The fusing current of the fuse is usually 1.5~2.0 times the rated current. For example, if the total power of all electrical appliances exceeds 1100 watts in normal household use, choose a 5-amp fuse, and use a No. 20 fuse with a diameter of 0.98 mm. When the current exceeds 7.5 amps to 10 amps, the fuse will blow Automatic fusing to achieve the purpose of protection;
(3) If the selected and used fuse meets the specifications and the fuse is often blown, it means that there is a problem with the electrical circuit and electrical equipment, and an electrician should be asked to find out the cause and eliminate the hidden danger in time. Do not replace the thick fuse at will simply replace it with copper wire or iron wire.
(4) When installing a fuse on the power switch (switch), it is not allowed to operate with power on. The power switch should be pulled apart to disconnect the power supply; turn the fuse clockwise around the fastening screw for one week, and tighten the screw with a gasket until Do not tighten the fuse too tightly until it is tightened firmly; in addition, the fuse should not be pulled too tightly between the other fastening screws, and there should be a margin to prevent the fuse from being injured. Usually, the power switch and the fuse cannot be exposed, and the bakelite cover must be covered to ensure safety;
(5) Fuse blown in daily use: The first case is that the middle is broken but both sides are intact, the excessive load current causes the fuse to blow or the fuse is damaged, and the melting point is lowered, but the current is not too large. The second situation is that the fuse is completely melted when the fuse is blown, and there are burn marks and black and white gray around the fastening screw. This is caused by an instantaneous short circuit of the power supply, and the short circuit current is too large. Blindly install a thicker fuse without finding out the reason. To prevent damage to electrical appliances and causing a fire.
